Videos by Karl J . Wittmann
Habitat and swimming activity of Heteromysis abednavandii in an aquarium of the public institutio... more Habitat and swimming activity of Heteromysis abednavandii in an aquarium of the public institution 'Haus des Meeres' in Vienna (Austria). Accompanying crustaceans are the snapping shrimp Alpheus bellulus Miya & Miyake, 1969, and a swarm of the copepod Euaugaptilus sp. 22 views
Biogeography by Karl J . Wittmann
European Journal of Taxonomy, 2024
Twenty-one species of Mysidae were sampled by three ANDEEP expeditions to the Southern Ocean with... more Twenty-one species of Mysidae were sampled by three ANDEEP expeditions to the Southern Ocean with epibenthic sledges dragged over the deep-sea floor in the realm of 58-71° S and 00-65° W, depth 774-5190 m. Previously known ranges are significantly extended southward for four species and to greater depth in the same four species plus two other species. Supplementary descriptions are given for Amblyops tattersalli and Dactylamblyops murrayi, and a first description of a (subadult) male for Thalassomysis tattersalli. The definitions of the genera Amphiakrops gen. nov., Chelamblyops gen. nov., Desmocornea gen. nov. and Schizurakrops gen. nov. are mainly based on the structure of the eyes as well as of the antennal peduncle, chelate second thoracic endopod and telson. These structures are also important for the descriptions of Amblyops arianii sp. nov., A. bipapillatus sp. nov., Amblyopsoides fenestragothica sp. nov., A. lepidophthalma sp. nov., Amphiakrops brandtae gen. et sp. nov., Dactylamblyops benthophilus sp. nov., Desmocornea subchelata gen. et sp. nov., Paramblyops petrescui sp. nov., Schizurakrops meesi gen. et sp. nov., Scolamblyops muehlenhardtae sp. nov., Stellamblyops doryphorus sp. nov. and Mysidella antarctica sp. nov. Six previously described taxa are recombined as Amblyopsoides laticauda comb. nov., Amphiakrops bidigitatus comb. nov., A. japonicus comb. nov., Chelamblyops globorostris comb. nov., Meierythrops tattersalli comb. nov. and M. triangulatus comb. nov. One species is revised back to the initial combination as Dactylamblyops japonicus. All except one (Mysidella antarctica sp. nov.) newly described (12), newly recombined (6) or back-combined (1) species belong to the Erythropinae. Keys to the resulting 61 genera and 263 species of Erythropinae and 18 species of Mysidellinae are given at the worldwide scale. Ocular papillae with a terminal pore (sensory pore organ) are recorded in nine ANDEEP species. The organ of Bellonci is identified on the reduced eyes in 16 species, among which D. subchelata gen. et sp. nov. has many ommatidia arranged in a self-contained ribbon which shows a banded rhabdom only in non-adults. Reduction of visual elements together with shrinking of ocular papillae during ontogenetic development suggest that nonadults of D. subchelata and T. tattersalli stay in the photic zone for feeding and growth and then descend only once during their lifetime to the abyss for reproduction.
arthropoda, 2023
Why do the eyes remain comparatively large whereas the cornea is reduced in most troglobiont mysi... more Why do the eyes remain comparatively large whereas the cornea is reduced in most troglobiont mysids? Are there any important organ size-dependent functions served by non-visual eye rudiments? This issue was approached by measuring eye structures in five tro-globiont species of Mysida and two Stygiomysida compared with 14 troglophile and 49 trogloxene Mysida species. The Organ of Bellonci (OB) was found in all Mysida and as first records also in Stygiomysida. The length of OBs increased with individual body length and eye length in four examined species: from postnauplioid larvae to adult stage in a troglophile and a trogloxene mysid species examined; and from juveniles to adults in a troglobiont mysid and a troglobiont stygiomysid. At the interspecific level, eye length was on average 26% shorter at a given body length while the OB was 40% longer at a given body length and 54% longer at a given eye length, respectively, in adult troglobionts compared with trogloxene mysids. The OB is clearly proliferating while the cornea is reduced in troglobionts. This points to sensory functions (possibly together with other functions). The sensory pore organ was found in all 15 Mysida species whose eyes were mounted on slides, and a first record of this organ was also found in Stygiomysida.
Checklist of the Italian Fauna. Version 1.0. Last update: 2021-05-31, 2021
Online database of the fauna of Italy. Census in 2021 gave three species of Lophogastrida, two St... more Online database of the fauna of Italy. Census in 2021 gave three species of Lophogastrida, two Stygiomysida, and 61 Mysida (plus four non-nominotypical subspecies) from marine, brackish , and limnic habitats.
Wittmann K., 2021. Crustacea Malacostraca Mysidacea.
In: Bologna M.A., Zapparoli M., Oliverio M., Minelli A., Bonato L., Cianferoni F., Stoch F. (eds.), Checklist of the Italian Fauna. Version 1.0. Last update: 2021-05-31. Available at: https://www.lifewatchitaly.eu/en/initiatives/checklist-fauna-italia-en/checklist/
Similar to other small invertebrates, the conservation status of the crustacean orders Mysida and... more Similar to other small invertebrates, the conservation status of the crustacean orders Mysida and Stygiomysida is insufficiently established. It has so far only been estimated for two out of 1183 species worldwide. Here we provide first attempt to assess the conservation status of all known continental species of mysid and stygiomysid crustaceans on both global and national levels. A total of 86 species plus subspecies are currently known to inhabit fresh and other continental waters globally. Most taxa are rather poorly studied, thus remaining in the category data deficient (DD). Three species are critically endangered (CR): Diamysis pusilla, endemic of the Eastern Caspian Sea, found only in Kazakhstan and Turkmenistan and not recorded since 1930s, and two disappearing species from the Salento Peninsula (SE Italy), D. camassai from brackish semisubterranean habitats (dolinas), and the subterranean Stygiomysis hydruntina. Three stenoendemic species are considered endangered (EN): Troglomysis vjetrenicensis, from Vjetrenica cave in Bosnia and Herzegovina, D. lacustris from Lake Scutari, on the border between Montenegro and Albania, and Spelaeomysis bottazzii, from groundwater of the Salento Peninsula, SE Italy. Two stenoendemic species and a subspecies are considered vulnerable (VU): Paramysis (Serrapalpisis) kosswigi, from Lake Işikli in Turkey together with several springs, P. (S.) lacustris turcica, endemic of Lake Beyşehir in Turkey, and D. hebraica known from only three coastal streams in Israel. Seven species plus subspecies are probably nearly threatened (NT): the Caspian Mysis amblyops, M. macrolepis, M. microphthalma, Paramysis (Metamysis) inflata, P. (P.) eurylepis, Schistomysis elegans, and the Adriatic freshwater species D. fluviatilis. Factors posing risks on mysids and stygomysids are hydrological and climate effects, habitat degradation , sediment intrusion, deforestation of watersheds, damage of bottom sediments, and to a minor extent illegal commerce.
Rapports de la Commission internationale pour l'Exploration scientifique de la Mer Méditerranée, 1983
Nous avons étudié la faune vagile associée aux feuilles de Posidonia oceanica d'un herbier de l'I... more Nous avons étudié la faune vagile associée aux feuilles de Posidonia oceanica d'un herbier de l'Ile d'Ischia (Golfe de Naples). On a examiné 12 stations localisées entre 1 et 30m de profondeur. On a pu reconnaître 4 groupements cénotiques disposés le long du gradient de profondeur, dont la distribution peut être expliquée sourtout par la variation quali-quantitative de 1'hydrodynamisme.
Annalen des Naturhistorischen Museums in Wien, 1986
The seasonal and morphogeographic differentiation of populations of Leptomysis lingvura (SARS) , ... more The seasonal and morphogeographic differentiation of populations of Leptomysis lingvura (SARS) , L. heterophila n. sp., and L. posidoniae n. sp. is studied in detail. Main diagnostic features are scales at the outer ventral margin of the mandibula in L. heterophila n. sp., the eyestalks completely covered with scales in L. posidoniae n. sp., and the lack of both features together with large size of body chromatophores in L. lingvura (SARS). The latter species occurs in three morphologically distinct forms: at Atlantic coasts L. lingvura lingvura (SARS) with the exopod of fourth pleopod of males 10 to 11-segmented; in the central and west Mediterranean and in the Aegean Sea the revalidated L. lingvura marioni (GOURRET) having this pleopod 8 to 9-segmented and the first thoracic epipod with a large seta; and in the Adriatic and the Ionian Sea L. lingvura adriatica n. ssp. without this seta. Adriatic populations of L. lingvura and L. heterophila each show morphologically different over-wintering and summer generations. These differences are weaker or do not exist in west or in central Mediterranean populations, respectively.
Fauna der Antarktis, 1990
Mysidacea (Schwebgarnelen)
Garnelenförmige Peracarida mit freien, gestielten Augen; Brustschild d... more Mysidacea (Schwebgarnelen)
Garnelenförmige Peracarida mit freien, gestielten Augen; Brustschild die 5 hinteren Brustsegmente großteils überdachend, aber nicht mit diesen verwachsen; 8 Paar 2ästige Brustbeine; Außenäste fast immer vielsegmentig; Innenäste am 1. und 2. Brustsegment als Kieferfüße, ansonsten als Greifbeine, ausgebildet; 5 Schwimmbeinpaare; Weibchen mit Brutbeutel aus 2 - 7 Brutplattenpaaren.
Mysidaceen werden oft mit dem Mysis-Stadium von Dekapoden und mit Euphausiaceen verwechselt. Bei diesen ist der Brustschild mit (fast) allen Brustsegmenten verwachsen, die Uropoden haben niemals eine Statozyste. Dekapoden mit 3 Paar Kieferfüßen und meist Scheren am 4. Brustbeinpaar, Euphausiaceen ohne Kieferfüße, dafür meist Leuchtorgane und als Adultus ein Paar seitlicher Anhänge vor der Spitze des Telson.
Bei der Kopulation wird das Sperma in den Brutbeutel eingebracht. Danach werden die Eier in den Brutbeutel abgelegt und befruchtet. Aus der Eihülle schlüpft das Nauplioid-, und nach der ersten Häutung das Postnauplioid-Stadium. Kurz nach oder vor der zweiten Larvalhäutung zum freibeweglichen Juvenilstadium erfolgt die Freigabe aus dem Brutbeutel. Nach weiteren 10 - 11 postlarvalen Häutungen wird die Geschlechtsreife erreicht (bei Antarctomysis maxima möglicherweise nach 2 Jahren). Bezogen auf die große Körperlänge (20 - 60 mm) findet man in der Antarktis nur wenige (20 - 35) aber sehr große (0,5 - 1,3 mm) Eier. Nach Erfahrungen an arktischen Formen ist zu vermuten, daß Weibchen 1 - 2 Bruten nach einer Inkubationszeit von je 5 - 9 Monaten absetzen.
In den Mägen findet man meist Detritus, Diatomeen und Zooplankton. Plankton und Sinkstoffe werden durch die rotierenden Außenäste der Brustfüße herbei- bzw. vom Boden aufgewirbelt. Oft wird gezielt nach Nahrung gegriffen. Vielfach epibenthisch, meist hyperbenthisch, d.h. in dauernder Schwimmaktivität knapp über dem Bodengrund schwebend. Vertikalwanderungen treten oft auf.
Südlich des 60. Breitengrades sind 26 Arten nachgewiesen; außer der endemischen 264 Antarctomysis sind alle Genera kosmopolitisch.
Berichte zur Polarforschung, 1991
In den reichhaltigen benthischen Lebensgemeinschaften des Weddellmeeres sind die Mysidacea faunis... more In den reichhaltigen benthischen Lebensgemeinschaften des Weddellmeeres sind die Mysidacea faunistisch nahezu unbekannt. Nur wenig besser ist die Situation für die gesamte Hochantarktis, aus der nur 26 Arten nachgewiesen sind. Bei Vergleich mit der Arktis und den in beiden Polargebieten bisher eingesetzten Sammelmethoden ist es hoch wahrscheinlich, daß die tatsächliche Artenzahl weit über dem Doppelten liegt. Wie man von wärmeren Meeresgebieten weiß, kann erst der Einsatz spezifischer Methoden eine wesentliche Verbesserung der Faunenkenntnis bewirken. Besonders effizient ist der Hyperbenthosschlitten mit Netzen geringer Maschenweite, wie er nunmehr erstmals im Weddellmeer zum Einsatz gelangt. Nach der systematischen Aufsammlung in den Schelfgebieten und am Kontinentalabhang soll das Material monographisch aufgearbeitet werden, um späteren synökologischen und ökophysiologischen Forschungen eine solide Basis zu geben.
Neben der zoogeographischen und taxonomischen Bearbeitung werden auch ökophysiologische und biomineralogische Forschungsziele verfolgt. Geplant sind Lebendbeobachtungen unter kryophysiologischen Aspekten. Die Kenntnis rezenter und subfossiler Statolithen soll die Grundlage zur Aufklärung der Evolution, Faunengeschichte und Biostratigraphie der in manchen geologischen Sedimenten reichhaltig konservierten Statolithen erweitern. Dafür ist frisch gewonnenes Rezentmaterial im Vergleich zu Statolithen aus marinen Sedimenten unter taxonomischen, morphologischen, biomineralogischen, chemisch-analytischen und aktuopaläontologischen Aspekten zu studieren.
VDI Berichte, 1991
Die Artenzahl der Isopoden in den verschiedenen Stadtbiotopen erweist sich als empfindlicher Zeig... more Die Artenzahl der Isopoden in den verschiedenen Stadtbiotopen erweist sich als empfindlicher Zeiger für Versiegelungs- und Verstädterungsgrad der Böden, wohl verursacht durch die Reaktion auf unterschiedliche Feuchtigkeit. Im städtischen Kernbereich dominiert Porcellio scaber. Durch regelmäßiges Auftreten und hohe Akkumulationsraten erweist sie sich als geeigneter Kandidat für die Schwermetall-Indikation. Deutlich ist die Korrelation von Bleigehalt der Asseln und Verkehrsbelastung. Bei den toxischen Schwermetallen Pb und Cd findet man hohe Schwankungen in Monatsabständen. Bei essentiellen Schwermetallen wurden keine (Zn) oder nicht signifikante (Cu) temporäre Unterschiede gefunden.
Berichte zur Polarforschung, 1991
Als Grundlage zur Monographienserie Antarktisches Benthos im DFG-Schwerpunktprogramm Antarktisfor... more Als Grundlage zur Monographienserie Antarktisches Benthos im DFG-Schwerpunktprogramm Antarktisforschung wurde die Untersuchung einer Reihe benthischer Evertebraten im Südsommer 1989/90 in Angriff genommen. Bearbeitet wurden Vorkommen und Verbreitung von Hydroidea, Kamptozoa (Entoprocta), Priapulida, Pogonophora, Phoronida, Pantopoda (Pycnogonida), Cirripedia und Mysidacea. Fanggeräte waren Agassiz-Trawl und Epibenthosschlitten.
Von 45 Hols an 26 Stationen lagen 41 in der Schelfregion von 80-600 m Tiefe. Davon entfielen 25 Hols auf das östliche Weddellmeer zwischen 8° und 28° W, 16 Hols auf den westlichen Bereich zwischen 49° und 611 W (s. Routenkarte Abschn. 4). Vier Fänge wurden in 600-1000 m Tiefe am Kontinentalabhang zwischen 23° und 31° W eingeholt. Ein Faunenprofil aus 4 Stationen von 1000-200 m sollte über die Tiefenverteilung Auskunft geben. Westlich des Filchner-Ronne-Schelfeises beeinträchtigten tiefe Temperaturen bis -19 °C die Auslese empfindlicher Formen erheblich, da der Netzinhalt schon beim Hieven durchfror.
Im östlichen Teil des Untersuchungsgebietes dominieren gröbere Sedimente, im Westen dagegen Sand- und Schlammböden. Generalisierend läßt sich feststellen, daß das Faunenspektrum sessiler Organismen in der stärker strömungsexponierten Steilhangzone des östlichen Weddellmeeres wesentlich breiter, der Individuenreichtum deutlich größer ist als in dem geringer strömungsexponierten, flachen südwestlichen Schelf. Einige vagile epi- und hyperbenthische Gruppen, wie Mysidacea und Cumacea zeigen hingegen ihre größte Entfaltung über den weniger exponierten flacheren Feinsedimentböden beider Meeresteile.
Die wenigen Tiefenfänge waren sehr heterogen. Daher sind bei zukünftigen Benthosarbeiten vermehrt Hols aus größeren Tiefen wünschenswert.
Lauterbornia, 1995
Secondary title: On the immigration of potamophilous Malacostraca into the Upper Danube River: Li... more Secondary title: On the immigration of potamophilous Malacostraca into the Upper Danube River: Limnomysis benedeni (Mysidacea), Corophium curvispinum (Amphipoda), and Atyaephyra desmaresti (Decapoda)
Abstract: Since 1982/83 Limnomysis benedeni migrated along the River Danube from Vienna in several steps to Passau. Populations of Corophium curvispinum which migrated upstreams in the rivers Main and Danube came into contact by the Main-Danube-Channel. In its upstream migration in the Rhine-Main system, Atyaephyra desmaresti extended its distribution in the Main-Danube-Channel and approached closely to the highest point at 406 m above sea level. Collections inside ships and on the exterior wall of a ship point to an important role of dispersion by navigation.
Kurzfassung: Limnomysis benedeni hat sich in mehreren Ausbreitungsschüben seit 1982/83 die Donau aufwärts von Wien bis nach Passau ausgebreitet. Die den Main und die Donau aufwärts migrierenden Populationen von Corophium curvispinum sind über den Main-Donau-Kanal in Kontakt getreten. Atyaephyra desmaresti ist vom Rhein-Mainsystem kommend im Main-Donau-Kanal bis nahe an die Scheitelhaltung gelangt. Nachweise im Inneren von Schiffen und an der Augenseite des Schiffsbodens sprechen für eine bedeutende Rolle der Verschleppung durch die Schiffahrt.
Miscellanea Zoologica Hungarica, 1995
The Danube between Harta (rkm 1549) and Kehlheim (rkm 2410) was sampled qualitatively in 1985-199... more The Danube between Harta (rkm 1549) and Kehlheim (rkm 2410) was sampled qualitatively in 1985-1995 at all seasons. Eighteen epigean species of Malacostraca (Janiridae, Asellidae, Gammaridac, Talitridac, Corophiidae, Mysidae, Astacidae, Cambaridae) were recorded. The malacostracan fauna shows a distinct longitudinal zonation in the River Danube. At least nine species are of Ponto-Caspian origin. The actual distribution patterns were analyzed with respect to former studies. At least six species were strongly expansive during the last few decades. Navigation appears to be among the crucial factors for this dispersion.
Global Biodiversity Research. International Senckenberg Conference, Frankfurt 1996, 1996
So far, 1050 species of Mysidacea (Peracarida, Crustacea) were described and classified. The main... more So far, 1050 species of Mysidacea (Peracarida, Crustacea) were described and classified. The main number, about 90%, is marine (mainly coastal) species, the rest belongs to brackish, freshwater and subterranean forms. The number of known pelagic species showed a roughly linear increment since 1860. Descriptions of benthopelagic and benthic species are still increasing an a logarithmic scales. Due to this exponential growth form, no prediction an the final number of living species can be made from the time-series of descriptions, except that the final number will be large compared with the actual one.
As in most living forms, there is a strong latitudinal decrease of species numbers and diversity from the equator towards higher latitudes. At present, about twice the number of species is known from the northern hemisphere compared to the southern one. This may be indicative of a strong bias in the degree of exploration.
The number of known benthopelagic and benthic species is about four times that of pelagic species, a relation which increases year by year. Pelagic species are efficiently sampled and further species may be expected mainly in deep waters. New types of epibenthic sledges recently strongly increased the efficiency of benthopelagic catches, and resulted in a great number of new species. Sampling methods for benthic species are still at the beginning of development; with the use of traps, examination of molluscs shells, sponges and corals, and with night sampling of diurnally emergent species.
Most sea areas of the globe were poorly explored for mysid species. Best known are the faunas of Japan waters, Caribbean, North AtIantic, Black Sea, and Mediterranean. Projections of species diversity and numbers in well known areas suggest that the globe may be populated by a reasonable minimum of about 4000 living species. Plausibility rather than reason supports a maximum estimate of about 10.000 mysid species.
Boletim do Museu Municipal do Funchal, 1998
In the Madeira Archipeiago, 19 coastal mysid species, five of them new to science, were collected... more In the Madeira Archipeiago, 19 coastal mysid species, five of them new to science, were collected by handnet and by boat operated plankton and bottom nets. These belong to nine different genera, Lophogaster, Siriella, Anchialina, Haplostylus, Erythrops, Leptomysis, Hemimysis, Mesopodopsis, and Heteromysis. So far, 17 coastal mysid species, five of them new to science, were recorded for the Canary Archipelago. These spceies belang to twelve different genera, Siriella, Anchialina, Gastrosaccus, Haplostylus, Erythrops, Leptomysis, Paraleptomysis, Mysidopsis, Hemimysis , Schistomysis, Paramysis, and Heteromysoides.
Two species are known only from the Madeira and Canary islands, four other species appear to be endemic to Madeira, and three more species appear to be endemic to the Canary Islands. 47 % of the Madeiran species were also encountered at the Canary Islands, 53 % of the Canarian species were also recorded for Madeira. Three species were previously regarded as Mediterranean endemics. There is a marked northem influence, in so far as 10 of the 16 `Mediterranean' species are also distributed in boreal to subtropical zones of the NE-Atlantic, extending as far north as the Norwegian coasts.
The (sub)tropical Westafrican fauna is represented by two species only, Lophogaster challengeri and Schistomysis sp. A. A new Heteromysis species inhabits gastropod shells occupied by the hermit crab Dardanus callidus; such associations have been recorded from the Red Sea and the Indopacific; for the Atlantic, this is the first record of a mysid shrimp commensal with a hermit crab. A second new Heteromysis species was found only in association with the sea anemone Telmatactis cricoides; sirnilar associations had so far been reported only from the Western Atlantic.
Abstracts of the 14th International Symposium of Biospeleology, 1999
On both sides of the Atlantic closely related genera are known where the diverse species represen... more On both sides of the Atlantic closely related genera are known where the diverse species represent a broad spectrum from euthalassobious or euepigean forms to eustygophilous and stygobiont species. OId world representatives are the genera Diamysis (fresh- to metahaline waters; Euro-African: mainly Mediterranean and Black Sea) and Troglomysis (freshwater cave in Herzegovina, E-Mediterranean). New world representatives are Surinamysis (freshwaters, S-America), Parvimysis (fresh- to euhaline waters in Central and South America) and Antromysis (cave
waters and crab burrows in Caribbean and Mexico). Obvious adaptations to the underground aquatic habitats are different degrees of reduction of the eyes and of the static organs, where statolith diameters are smaller in hypogean compared with epigean forms. Parallel evolution may have occurred an eastern and western side of the Atlantic resulting in stygobiont forms (Troglomysis and Antromysis, respectively). Comparison of Diamysis populations living in brackish dolinas environments with those from brackish springs and coastal marine habitats of the same region suggests that adaptation to the subterranean life may have a crucial step in the colonization of a typical semi-hypogean environment such as dolinas. Substantially consistent pathways may have been followed by Antrornysis anophelinae living in crab burrows: this is dwelling in crevicular habitats, often in combination with symbiosis with benthic macroorganisms, as is especially known from Heteromysis and Heteromysoides species.
Crustaceans and the biodiversity crisis, 1999
Among the 1078 taxa of mysids and lophogastrids so far described on a world-wide scale, there is ... more Among the 1078 taxa of mysids and lophogastrids so far described on a world-wide scale, there is a strong latitudinal decrease in species numbers and diversity from the equator towards higher latitudes. The number in the northern hemisphere is more than twice that of the southern part of the globe, and may be indicative of a strong bias in degree of exploration. Ninety-one percent are marine species, the remainder lives in brackish, fresh, or subterranean waters. Seventy-four percent are benthopelagic or benthic species, whereby, with the development of more efficient sampling methods, this percentage will tend to increase. Extrapolations departing from species numbers in well studied areas suggest that the globe may be populated by a minimum of around 4000 living species.
Areal regression or even complete extinction of populations due to human impact can be documented. Endangerment arises from the heavy pollution of coastal waters, desalination of estuaries and lagoons due to the construction of dykes and canals, artificial reconstruction of waters, groundwater drainage, and the repeated application of pesticides. The possible effects on native species caused by invasive ones dispersed by man across oceans or along artificial waterways is not known. If the current adverse trends continue, a substantial portion of the estimated figure of more than 3000 undescribed species may become extinct before being described by science.
Bulletin Zoölogisch Museum Universiteit van Amsterdam, 1999
The freshwater Mysidacea of The Netherlands are presently composed of three species. The indigeno... more The freshwater Mysidacea of The Netherlands are presently composed of three species. The indigenous mysid, Neomysis integer (Leach. 1814) has recently been joined by two Pontocaspian species, Limnomysis benedeni Czerniaysky, 1882 and Hemimysis anomala G.D. Sars, 1907. All three species now coexist in the Dutch Rhine. The present paper deals with the first records of L benedeni in The Netherlands with ecological notes on the three species.
Abstracts of the 14th International Symposium of Biospeleology, 1999
The aquatic fauna of the `Spunnulate', a system of brackish water dolinas at Torre Castiglione (l... more The aquatic fauna of the `Spunnulate', a system of brackish water dolinas at Torre Castiglione (lonian coast of Apulia; see Camassa, Ariani & Wittmann in this congress), was studied by monthly inspections from May 1998 to April 1999. Material was collected with hand operated plancton and bottom nets. The obtained faunistic list includes representatives of several phyla from Protozoa to Chordata -(the fish Gambusia, Anguilla and Blennius), passing through Platyhelminthes Turbellaria, Rotatoria, Nematoda, Mollusca Castropoda, Annelida Polychaeta and Arthropoda, whereby mainly Crustacea appeared as dominant elements. Among the crustaceans, four orders of Peracarida were present in this peculiar environment, where dark and light zones are close or in immediate contact: Tanaidacea (Tanais cavolinii, Isopoda (Jaera italica, Lekanesphaera hookeri), Amphipoda (Gammarus aequicauda, Orchestia gamarella), and notably the Mysidacea represented by two species with different degrees of eye reduction. These two taxa were previously reported only from aquatic subterranean (the stygobiont Spelaeomysis bottazzii or from epigean brackish to marine (Diamysis sp.) environments, and showed here to share, surprisingly, the same habitat.
Mémoires de Biospéologie, 2000
A brackish water dolinas system is described from the lonian coast of Apulia (SE-ltaly). These co... more A brackish water dolinas system is described from the lonian coast of Apulia (SE-ltaly). These collapse cavities are locally termed ‘Spunnulate‘ and are of late Pleistocene or Recent origin. Six dolinas, scattered over about 0.1 km2 were studied upon 5-11 inspections from May 1998 to April 1999. The area occupied by the dark zone ranged between 1% and 100% of the accessible water surface. Salinity showed temporal fluctuations of up to ± 2 ‰ within each dolina, where average values decreased with increasing sea distance, from about 8 ‰ at 120 m to about 6 ‰ at 450 m. Temperature was generaily in the range of 16-19°C (max. 21°C) at 0.2 m depth; pH was mostly in the range of 7-8 (max. 9.5). The available data, especially ionic composition (Cl = Na Mg = Ca K) clearly indicate that all the studied dolinas belong to the same water body in the underground, pertaining to deep groundwaters contaminated by sea water and chemically influenced by the corrosion of carbonatic rock. The aquatic fauna was found to include representatives of several phyla from Protozoa to Chordata (four fish species), passing through Platyhelminthes Turbellaria, Rotatoria, Nematoda, Mollusca Gastropoda, Annelida Polychaeta and Oligochaeta, and Arthropoda, whereby Crustacea appeared as dominant elements, with the presence of four orders of Peracarida: Mysidacea, Tanaidacea, Isopoda and Amphipoda. In line with the environmental characteristics, where dark and light zones are close or in immediate contact, the aquatic fauna appeared as a strongly heterogeneous complex in which several ecological and/or chorological components could be recognized: from essentially Iagoon-dwelling, typically epigean and mainly cosmopolitan species to stygophilic or stygobiontic, endemic taxa. These last are represented by two mysidacean species: the Apulian endemic lepidomysid Spelaeomysis bottazzii and an undescribed species of the mysid genus Diamysis, showing a significant degree of eye reduction, i.e. smaller cornea and smaller eyestalks with respect to congeneric, epigean populations living in brackish or marine waters of the same region. Eye reduction may be regarded as the result of an adaptive process where colonization of a semi-hypogean environment was a crucial, intermediate step.
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Biogeography by Karl J . Wittmann
Wittmann K., 2021. Crustacea Malacostraca Mysidacea.
In: Bologna M.A., Zapparoli M., Oliverio M., Minelli A., Bonato L., Cianferoni F., Stoch F. (eds.), Checklist of the Italian Fauna. Version 1.0. Last update: 2021-05-31. Available at: https://www.lifewatchitaly.eu/en/initiatives/checklist-fauna-italia-en/checklist/
Garnelenförmige Peracarida mit freien, gestielten Augen; Brustschild die 5 hinteren Brustsegmente großteils überdachend, aber nicht mit diesen verwachsen; 8 Paar 2ästige Brustbeine; Außenäste fast immer vielsegmentig; Innenäste am 1. und 2. Brustsegment als Kieferfüße, ansonsten als Greifbeine, ausgebildet; 5 Schwimmbeinpaare; Weibchen mit Brutbeutel aus 2 - 7 Brutplattenpaaren.
Mysidaceen werden oft mit dem Mysis-Stadium von Dekapoden und mit Euphausiaceen verwechselt. Bei diesen ist der Brustschild mit (fast) allen Brustsegmenten verwachsen, die Uropoden haben niemals eine Statozyste. Dekapoden mit 3 Paar Kieferfüßen und meist Scheren am 4. Brustbeinpaar, Euphausiaceen ohne Kieferfüße, dafür meist Leuchtorgane und als Adultus ein Paar seitlicher Anhänge vor der Spitze des Telson.
Bei der Kopulation wird das Sperma in den Brutbeutel eingebracht. Danach werden die Eier in den Brutbeutel abgelegt und befruchtet. Aus der Eihülle schlüpft das Nauplioid-, und nach der ersten Häutung das Postnauplioid-Stadium. Kurz nach oder vor der zweiten Larvalhäutung zum freibeweglichen Juvenilstadium erfolgt die Freigabe aus dem Brutbeutel. Nach weiteren 10 - 11 postlarvalen Häutungen wird die Geschlechtsreife erreicht (bei Antarctomysis maxima möglicherweise nach 2 Jahren). Bezogen auf die große Körperlänge (20 - 60 mm) findet man in der Antarktis nur wenige (20 - 35) aber sehr große (0,5 - 1,3 mm) Eier. Nach Erfahrungen an arktischen Formen ist zu vermuten, daß Weibchen 1 - 2 Bruten nach einer Inkubationszeit von je 5 - 9 Monaten absetzen.
In den Mägen findet man meist Detritus, Diatomeen und Zooplankton. Plankton und Sinkstoffe werden durch die rotierenden Außenäste der Brustfüße herbei- bzw. vom Boden aufgewirbelt. Oft wird gezielt nach Nahrung gegriffen. Vielfach epibenthisch, meist hyperbenthisch, d.h. in dauernder Schwimmaktivität knapp über dem Bodengrund schwebend. Vertikalwanderungen treten oft auf.
Südlich des 60. Breitengrades sind 26 Arten nachgewiesen; außer der endemischen 264 Antarctomysis sind alle Genera kosmopolitisch.
Neben der zoogeographischen und taxonomischen Bearbeitung werden auch ökophysiologische und biomineralogische Forschungsziele verfolgt. Geplant sind Lebendbeobachtungen unter kryophysiologischen Aspekten. Die Kenntnis rezenter und subfossiler Statolithen soll die Grundlage zur Aufklärung der Evolution, Faunengeschichte und Biostratigraphie der in manchen geologischen Sedimenten reichhaltig konservierten Statolithen erweitern. Dafür ist frisch gewonnenes Rezentmaterial im Vergleich zu Statolithen aus marinen Sedimenten unter taxonomischen, morphologischen, biomineralogischen, chemisch-analytischen und aktuopaläontologischen Aspekten zu studieren.
Von 45 Hols an 26 Stationen lagen 41 in der Schelfregion von 80-600 m Tiefe. Davon entfielen 25 Hols auf das östliche Weddellmeer zwischen 8° und 28° W, 16 Hols auf den westlichen Bereich zwischen 49° und 611 W (s. Routenkarte Abschn. 4). Vier Fänge wurden in 600-1000 m Tiefe am Kontinentalabhang zwischen 23° und 31° W eingeholt. Ein Faunenprofil aus 4 Stationen von 1000-200 m sollte über die Tiefenverteilung Auskunft geben. Westlich des Filchner-Ronne-Schelfeises beeinträchtigten tiefe Temperaturen bis -19 °C die Auslese empfindlicher Formen erheblich, da der Netzinhalt schon beim Hieven durchfror.
Im östlichen Teil des Untersuchungsgebietes dominieren gröbere Sedimente, im Westen dagegen Sand- und Schlammböden. Generalisierend läßt sich feststellen, daß das Faunenspektrum sessiler Organismen in der stärker strömungsexponierten Steilhangzone des östlichen Weddellmeeres wesentlich breiter, der Individuenreichtum deutlich größer ist als in dem geringer strömungsexponierten, flachen südwestlichen Schelf. Einige vagile epi- und hyperbenthische Gruppen, wie Mysidacea und Cumacea zeigen hingegen ihre größte Entfaltung über den weniger exponierten flacheren Feinsedimentböden beider Meeresteile.
Die wenigen Tiefenfänge waren sehr heterogen. Daher sind bei zukünftigen Benthosarbeiten vermehrt Hols aus größeren Tiefen wünschenswert.
Abstract: Since 1982/83 Limnomysis benedeni migrated along the River Danube from Vienna in several steps to Passau. Populations of Corophium curvispinum which migrated upstreams in the rivers Main and Danube came into contact by the Main-Danube-Channel. In its upstream migration in the Rhine-Main system, Atyaephyra desmaresti extended its distribution in the Main-Danube-Channel and approached closely to the highest point at 406 m above sea level. Collections inside ships and on the exterior wall of a ship point to an important role of dispersion by navigation.
Kurzfassung: Limnomysis benedeni hat sich in mehreren Ausbreitungsschüben seit 1982/83 die Donau aufwärts von Wien bis nach Passau ausgebreitet. Die den Main und die Donau aufwärts migrierenden Populationen von Corophium curvispinum sind über den Main-Donau-Kanal in Kontakt getreten. Atyaephyra desmaresti ist vom Rhein-Mainsystem kommend im Main-Donau-Kanal bis nahe an die Scheitelhaltung gelangt. Nachweise im Inneren von Schiffen und an der Augenseite des Schiffsbodens sprechen für eine bedeutende Rolle der Verschleppung durch die Schiffahrt.
As in most living forms, there is a strong latitudinal decrease of species numbers and diversity from the equator towards higher latitudes. At present, about twice the number of species is known from the northern hemisphere compared to the southern one. This may be indicative of a strong bias in the degree of exploration.
The number of known benthopelagic and benthic species is about four times that of pelagic species, a relation which increases year by year. Pelagic species are efficiently sampled and further species may be expected mainly in deep waters. New types of epibenthic sledges recently strongly increased the efficiency of benthopelagic catches, and resulted in a great number of new species. Sampling methods for benthic species are still at the beginning of development; with the use of traps, examination of molluscs shells, sponges and corals, and with night sampling of diurnally emergent species.
Most sea areas of the globe were poorly explored for mysid species. Best known are the faunas of Japan waters, Caribbean, North AtIantic, Black Sea, and Mediterranean. Projections of species diversity and numbers in well known areas suggest that the globe may be populated by a reasonable minimum of about 4000 living species. Plausibility rather than reason supports a maximum estimate of about 10.000 mysid species.
Two species are known only from the Madeira and Canary islands, four other species appear to be endemic to Madeira, and three more species appear to be endemic to the Canary Islands. 47 % of the Madeiran species were also encountered at the Canary Islands, 53 % of the Canarian species were also recorded for Madeira. Three species were previously regarded as Mediterranean endemics. There is a marked northem influence, in so far as 10 of the 16 `Mediterranean' species are also distributed in boreal to subtropical zones of the NE-Atlantic, extending as far north as the Norwegian coasts.
The (sub)tropical Westafrican fauna is represented by two species only, Lophogaster challengeri and Schistomysis sp. A. A new Heteromysis species inhabits gastropod shells occupied by the hermit crab Dardanus callidus; such associations have been recorded from the Red Sea and the Indopacific; for the Atlantic, this is the first record of a mysid shrimp commensal with a hermit crab. A second new Heteromysis species was found only in association with the sea anemone Telmatactis cricoides; sirnilar associations had so far been reported only from the Western Atlantic.
waters and crab burrows in Caribbean and Mexico). Obvious adaptations to the underground aquatic habitats are different degrees of reduction of the eyes and of the static organs, where statolith diameters are smaller in hypogean compared with epigean forms. Parallel evolution may have occurred an eastern and western side of the Atlantic resulting in stygobiont forms (Troglomysis and Antromysis, respectively). Comparison of Diamysis populations living in brackish dolinas environments with those from brackish springs and coastal marine habitats of the same region suggests that adaptation to the subterranean life may have a crucial step in the colonization of a typical semi-hypogean environment such as dolinas. Substantially consistent pathways may have been followed by Antrornysis anophelinae living in crab burrows: this is dwelling in crevicular habitats, often in combination with symbiosis with benthic macroorganisms, as is especially known from Heteromysis and Heteromysoides species.
Areal regression or even complete extinction of populations due to human impact can be documented. Endangerment arises from the heavy pollution of coastal waters, desalination of estuaries and lagoons due to the construction of dykes and canals, artificial reconstruction of waters, groundwater drainage, and the repeated application of pesticides. The possible effects on native species caused by invasive ones dispersed by man across oceans or along artificial waterways is not known. If the current adverse trends continue, a substantial portion of the estimated figure of more than 3000 undescribed species may become extinct before being described by science.
Wittmann K., 2021. Crustacea Malacostraca Mysidacea.
In: Bologna M.A., Zapparoli M., Oliverio M., Minelli A., Bonato L., Cianferoni F., Stoch F. (eds.), Checklist of the Italian Fauna. Version 1.0. Last update: 2021-05-31. Available at: https://www.lifewatchitaly.eu/en/initiatives/checklist-fauna-italia-en/checklist/
Garnelenförmige Peracarida mit freien, gestielten Augen; Brustschild die 5 hinteren Brustsegmente großteils überdachend, aber nicht mit diesen verwachsen; 8 Paar 2ästige Brustbeine; Außenäste fast immer vielsegmentig; Innenäste am 1. und 2. Brustsegment als Kieferfüße, ansonsten als Greifbeine, ausgebildet; 5 Schwimmbeinpaare; Weibchen mit Brutbeutel aus 2 - 7 Brutplattenpaaren.
Mysidaceen werden oft mit dem Mysis-Stadium von Dekapoden und mit Euphausiaceen verwechselt. Bei diesen ist der Brustschild mit (fast) allen Brustsegmenten verwachsen, die Uropoden haben niemals eine Statozyste. Dekapoden mit 3 Paar Kieferfüßen und meist Scheren am 4. Brustbeinpaar, Euphausiaceen ohne Kieferfüße, dafür meist Leuchtorgane und als Adultus ein Paar seitlicher Anhänge vor der Spitze des Telson.
Bei der Kopulation wird das Sperma in den Brutbeutel eingebracht. Danach werden die Eier in den Brutbeutel abgelegt und befruchtet. Aus der Eihülle schlüpft das Nauplioid-, und nach der ersten Häutung das Postnauplioid-Stadium. Kurz nach oder vor der zweiten Larvalhäutung zum freibeweglichen Juvenilstadium erfolgt die Freigabe aus dem Brutbeutel. Nach weiteren 10 - 11 postlarvalen Häutungen wird die Geschlechtsreife erreicht (bei Antarctomysis maxima möglicherweise nach 2 Jahren). Bezogen auf die große Körperlänge (20 - 60 mm) findet man in der Antarktis nur wenige (20 - 35) aber sehr große (0,5 - 1,3 mm) Eier. Nach Erfahrungen an arktischen Formen ist zu vermuten, daß Weibchen 1 - 2 Bruten nach einer Inkubationszeit von je 5 - 9 Monaten absetzen.
In den Mägen findet man meist Detritus, Diatomeen und Zooplankton. Plankton und Sinkstoffe werden durch die rotierenden Außenäste der Brustfüße herbei- bzw. vom Boden aufgewirbelt. Oft wird gezielt nach Nahrung gegriffen. Vielfach epibenthisch, meist hyperbenthisch, d.h. in dauernder Schwimmaktivität knapp über dem Bodengrund schwebend. Vertikalwanderungen treten oft auf.
Südlich des 60. Breitengrades sind 26 Arten nachgewiesen; außer der endemischen 264 Antarctomysis sind alle Genera kosmopolitisch.
Neben der zoogeographischen und taxonomischen Bearbeitung werden auch ökophysiologische und biomineralogische Forschungsziele verfolgt. Geplant sind Lebendbeobachtungen unter kryophysiologischen Aspekten. Die Kenntnis rezenter und subfossiler Statolithen soll die Grundlage zur Aufklärung der Evolution, Faunengeschichte und Biostratigraphie der in manchen geologischen Sedimenten reichhaltig konservierten Statolithen erweitern. Dafür ist frisch gewonnenes Rezentmaterial im Vergleich zu Statolithen aus marinen Sedimenten unter taxonomischen, morphologischen, biomineralogischen, chemisch-analytischen und aktuopaläontologischen Aspekten zu studieren.
Von 45 Hols an 26 Stationen lagen 41 in der Schelfregion von 80-600 m Tiefe. Davon entfielen 25 Hols auf das östliche Weddellmeer zwischen 8° und 28° W, 16 Hols auf den westlichen Bereich zwischen 49° und 611 W (s. Routenkarte Abschn. 4). Vier Fänge wurden in 600-1000 m Tiefe am Kontinentalabhang zwischen 23° und 31° W eingeholt. Ein Faunenprofil aus 4 Stationen von 1000-200 m sollte über die Tiefenverteilung Auskunft geben. Westlich des Filchner-Ronne-Schelfeises beeinträchtigten tiefe Temperaturen bis -19 °C die Auslese empfindlicher Formen erheblich, da der Netzinhalt schon beim Hieven durchfror.
Im östlichen Teil des Untersuchungsgebietes dominieren gröbere Sedimente, im Westen dagegen Sand- und Schlammböden. Generalisierend läßt sich feststellen, daß das Faunenspektrum sessiler Organismen in der stärker strömungsexponierten Steilhangzone des östlichen Weddellmeeres wesentlich breiter, der Individuenreichtum deutlich größer ist als in dem geringer strömungsexponierten, flachen südwestlichen Schelf. Einige vagile epi- und hyperbenthische Gruppen, wie Mysidacea und Cumacea zeigen hingegen ihre größte Entfaltung über den weniger exponierten flacheren Feinsedimentböden beider Meeresteile.
Die wenigen Tiefenfänge waren sehr heterogen. Daher sind bei zukünftigen Benthosarbeiten vermehrt Hols aus größeren Tiefen wünschenswert.
Abstract: Since 1982/83 Limnomysis benedeni migrated along the River Danube from Vienna in several steps to Passau. Populations of Corophium curvispinum which migrated upstreams in the rivers Main and Danube came into contact by the Main-Danube-Channel. In its upstream migration in the Rhine-Main system, Atyaephyra desmaresti extended its distribution in the Main-Danube-Channel and approached closely to the highest point at 406 m above sea level. Collections inside ships and on the exterior wall of a ship point to an important role of dispersion by navigation.
Kurzfassung: Limnomysis benedeni hat sich in mehreren Ausbreitungsschüben seit 1982/83 die Donau aufwärts von Wien bis nach Passau ausgebreitet. Die den Main und die Donau aufwärts migrierenden Populationen von Corophium curvispinum sind über den Main-Donau-Kanal in Kontakt getreten. Atyaephyra desmaresti ist vom Rhein-Mainsystem kommend im Main-Donau-Kanal bis nahe an die Scheitelhaltung gelangt. Nachweise im Inneren von Schiffen und an der Augenseite des Schiffsbodens sprechen für eine bedeutende Rolle der Verschleppung durch die Schiffahrt.
As in most living forms, there is a strong latitudinal decrease of species numbers and diversity from the equator towards higher latitudes. At present, about twice the number of species is known from the northern hemisphere compared to the southern one. This may be indicative of a strong bias in the degree of exploration.
The number of known benthopelagic and benthic species is about four times that of pelagic species, a relation which increases year by year. Pelagic species are efficiently sampled and further species may be expected mainly in deep waters. New types of epibenthic sledges recently strongly increased the efficiency of benthopelagic catches, and resulted in a great number of new species. Sampling methods for benthic species are still at the beginning of development; with the use of traps, examination of molluscs shells, sponges and corals, and with night sampling of diurnally emergent species.
Most sea areas of the globe were poorly explored for mysid species. Best known are the faunas of Japan waters, Caribbean, North AtIantic, Black Sea, and Mediterranean. Projections of species diversity and numbers in well known areas suggest that the globe may be populated by a reasonable minimum of about 4000 living species. Plausibility rather than reason supports a maximum estimate of about 10.000 mysid species.
Two species are known only from the Madeira and Canary islands, four other species appear to be endemic to Madeira, and three more species appear to be endemic to the Canary Islands. 47 % of the Madeiran species were also encountered at the Canary Islands, 53 % of the Canarian species were also recorded for Madeira. Three species were previously regarded as Mediterranean endemics. There is a marked northem influence, in so far as 10 of the 16 `Mediterranean' species are also distributed in boreal to subtropical zones of the NE-Atlantic, extending as far north as the Norwegian coasts.
The (sub)tropical Westafrican fauna is represented by two species only, Lophogaster challengeri and Schistomysis sp. A. A new Heteromysis species inhabits gastropod shells occupied by the hermit crab Dardanus callidus; such associations have been recorded from the Red Sea and the Indopacific; for the Atlantic, this is the first record of a mysid shrimp commensal with a hermit crab. A second new Heteromysis species was found only in association with the sea anemone Telmatactis cricoides; sirnilar associations had so far been reported only from the Western Atlantic.
waters and crab burrows in Caribbean and Mexico). Obvious adaptations to the underground aquatic habitats are different degrees of reduction of the eyes and of the static organs, where statolith diameters are smaller in hypogean compared with epigean forms. Parallel evolution may have occurred an eastern and western side of the Atlantic resulting in stygobiont forms (Troglomysis and Antromysis, respectively). Comparison of Diamysis populations living in brackish dolinas environments with those from brackish springs and coastal marine habitats of the same region suggests that adaptation to the subterranean life may have a crucial step in the colonization of a typical semi-hypogean environment such as dolinas. Substantially consistent pathways may have been followed by Antrornysis anophelinae living in crab burrows: this is dwelling in crevicular habitats, often in combination with symbiosis with benthic macroorganisms, as is especially known from Heteromysis and Heteromysoides species.
Areal regression or even complete extinction of populations due to human impact can be documented. Endangerment arises from the heavy pollution of coastal waters, desalination of estuaries and lagoons due to the construction of dykes and canals, artificial reconstruction of waters, groundwater drainage, and the repeated application of pesticides. The possible effects on native species caused by invasive ones dispersed by man across oceans or along artificial waterways is not known. If the current adverse trends continue, a substantial portion of the estimated figure of more than 3000 undescribed species may become extinct before being described by science.
Local population extinctions are related mainly to human impact on freshwater input into shallow coastal waters. Urbanization processes favoured the disappearance of brackish and freshwaters from the surface (through drainage and canalization) and the deterioration (through urban and industrial pollution) of the remaining ones, resulting in eutrophication of coastal waters and in impoverishment of the benthos, such as the visible regression of seagrasses. Increased species numbers in the 'insular' gulf reflect the lower degree of urbanization in the less polluted peripheral zones and the increased use of more specific sampling methods in combination with improved knowledge of mysid biology.
With the use of epibenthic nets during the day and at night, Heteromysis (Heteromysis) riedli sp. n. was sampled from Posidonia oceanica meadows on the Island of Ischia. The males of the new species are exceptional in having a pair of modified, backwards-oriented, flagellate setae terminally on the antennular trunc, while the females show only the usual forwards-oriented, smooth setae in this position.
Within the subfamily Leptomysinae (fam. Mysidae) the tribe Mysidopsini has five here acknowledged genera and 74 extant species. It embraces the genera Americamysis with six species from coasts of the NW-Atlantic (Narragansett Bay to Florida), the Caribbean and Gulf of Mexico; Brasilomysis with two species from the SW-Atlantic off Brazilian shores and from the Pacific coast of Ecuador; Cubanomysis with three species from the Caribbean, Gulf of California and southern California; Metamysidopsis with ten species from the Atlantic coasts of the USA to Brazil, Caribbean, Gulf of Mexico, and E-Pacific from California to Panama; and finally the globally occurring Mysidopsis. Not counting the below described new species and one fossil species, the latter genus comprises 53 extant species and one non-nominotypical subspecies. With regard to the great number of species, this genus is comparatively homogeneous, not considering the monotypic subgenera Pseudomysidopsis and Mysidopsoides.
New information
Mysidopsis canariensis sp. nov. is described from five islands of the Canaries and two islands of the Cape Verdes (NE-Atlantic). Records are from depths of 5 to 30 m, mainly over sand, also on stones and rock. It differs from the remaining NE-Atlantic and Mediterranean congeners among other features by the lateral margins of the telson distally having a longer bare portion. Among these species it differs from its northern vicariants M. iluroensis and M. gibbosa in addition by fewer spines on the endopod of uropods. In-situ-photos of M. canariensis sp. nov. document at least six strongly different color variants, four of which are strikingly similar to corresponding variants of M. jenseni from the NE-Pacific coast. The latter differs from all species of the E-Atlantic, including the new one, by a mid-dorsal lappet near the caudal margin of the female carapace. A key to the species of Mysidopsis from the E-Atlantic and Mediterranean is given.
Within the genus one may distinguish two morphogeographic groups, Euro-African species with a spine below the statocyst, and Indo-Australasian species without this spine. Detailed study from the entire distribution range indicates that M. slabberi (van Beneden) should be split into 4 species: the nominal form from the NE-Atlantic, Mediterranean, and Black Sea, with 5-8 segments on the tarsus of the fourth thoracic endopod; M. aegyptia n.sp., widely distributed in the Mediterranean, with 7-9 segments on this tarsus as well as dimorphic setation patterns on the eighth tarsus; M. tropicalis n.sp. from equatorial W-Africa with 5-6 segments and dimorphic setation patterns on the mandibular palp; and M. wooldridgei n.sp. from South African waters with 9-12 segments on the tarsal joint of the fourth thoracic appendage, respectively.
A key to the seven known species of the genus is given.
Egg sizes measured in six species were above or partly in the upper range of previous findings in subpolar to polar climates, while numbers of eggs per female were well within this range. Body sizes measured in nine species were mostly in the upper range. Incubating females were frequent (Diastylopsis goekei), less frequent (Diastylis mawsoni), infrequent (Cyclaspis gigas, Diastylis anderssoni armata, D. corniculata), or absent (Vaunthompsonia inermis, Paralamprops mawsoni, Leptostylis antipus) in the summer samples, thus pointing to the possibility of various breeding strategies in high Antarctic waters.
Die Analyse der Schwermetall-Gehalte (Pb, Cd, Ni, Cu, Zn) in den Schalen von drei Arten zeigte, daß Bithynia tentaculata in hohen Konzentrationen anreichert, Lymnaea stagnalis hingegen in sehr geringen. Im Mittelfeld liegt Radix ovata, die durch weite Verbreitung und hohe Verfügbarkeit für die Schwermetall-Indikation am besten geeignet erscheint.
Further expansion of Pontocaspian Mysidacea (Crustacea) into the middle and upper Danube: first records of Katamysis warpachowskyi for Hungary, Slovakia and Austria with notes on bionomy and ecological risk potential.
A further Pontocaspian representative of the family Mysidae, Katamysis warpachowskyi G.O. Sars, was recorded for the first time in the middle and upper reaches of the Danube River between km 1769 and km 1936 in October 2001. These records extend the known distribution range by 1700 km. K. warpachowskyi is therefore the third Mysidae species within 48 years, following Limnomysis benedeni Czerniavsky and Hemimysis anomala G.O. Sars, to have immigrated into the upper Danube. Regarding body form and behaviour, the euryhaline and oxyphilic K. warpachowskyi shows a clearly benthic habit. Its comparatively frequent occurrence along the banks of the main river course reflects a higher tolerance towards water currents and a stronger substrate relationship than in the remaining nine species in freshwater of the Danube system. Stomach contents and laboratory observations indicate a predominantly microherbivorous feeding mode. The presence of this species in four Danube harbours points to a possible rôle of dispersion by navigation. Due to its almost non-carnivorous and benthic habit, no similar detrimental effects on the ecosystem level - such as known from the invasion of deep, stagnant freshwaters by two other largely carnivorous species - are expected for K. warpachowskyi.
STUDY GOALS To determine toxic metal exposure levels (mercury, cadmium, lead, nickel) and their underlying factors.
METHOD Venous blood samples were provided by 159 volunteers (78 women, 81 men). Study participants filled in a questionnaire on medical history, lifestyle, nutrition, dental status, and smoking. Whole blood samples (2 ml) were wet-ashed with 2 ml HNO3 (suprapur) and 0.75 ml H2O2 in closed teflon vessels in a microwave system. Mercury (Hg), lead (Pb), cadmium (Cd), and nickel (Ni) concentrations were analyzed employing Atomic Absorption Spectrophotometry (GF-AAS; CV-AAS: hydride generation technique and amalgamation).
CONCLUSION Gender influences metal concentrations due to gender-related behaviour and life style. Further research is needed on the relationships between metal exposure and the immune system.
Die Bindung an bestimmte Biotope oder Standorte resultiert aus Prozessen der Anpassung von Organismen und ihrer Bedürfnisse an die Gesamtheit ihrer belebten und nicht-belebten Umwelt. Solche Bindungen konnten für eine Reihe von Aspekten der Umweltbeziehungen von Organismen aufgezeigt werden, vor allem die nicht-belebte Umwelt (klimatische und edaphische Faktoren), intraspezifische Beziehungen (Populationsdynamik und Sozialverhalten) und Beziehungen zur belebten Umwelt, wobei sich insbesondere die Beziehungen innerhalb der Nahrungskette und zu potentiellen Kommensalen zur Untersuchung anboten.
25 Mysidenspezies aus dem Sublittoral des Adriatischen und des Tyrrhenischen Meeres wurden über einen Zeitraum von fünf Jahren untersucht. Feldforschung wie auch Laborstudien wurden mit unterschiedlichen Methoden der Beobachtung, Aufsammlung, Markierung und Kultivierung der Organismen unternommen.
Die räumliche Verteilung der Mysiden war durch bathymetrische Muster, die Natur des Substrates, durch klimatische und edaphische Parameter und das Sozialverhalten charakterisiert, letzteres in Form der Schwarmbildung. Wachstum und Entwicklung zeigten Unterschiede je nach Spezies, Alter, Geschlecht, Erreichbarkeit von Nahrung, Jahreszeit und Temperatur. Abhängigkeiten der Populationsregulation von Dichte und Nahrungsverfügbarkeit konnten aufgezeigt werden. Die jahreszeitlichen Reproduktionszyklen zeigten deutliche Abhängigkeiten von Temperatur und Nahrungsverfügbarkeit. Die untersuchten Spezies waren überwiegend aktive Filtrierer. Diese Art von Ernährung war verbunden mit hoher migratorischer Aktivität, welche für die meisten Arten eine schwache Bindung an andere Organismen in den benthischen Lebensgemeinschaften zur Folge haben kann. Das stimmt damit überein, daß die untersuchten Mysiden sich zur Tageszeit im Allgemeinen als indigene Bewohner des bodennahen Pelagials erwiesen und daß sie geringere Spezifität zu benthischen Biotopen zeigten, an die sie eher durch klimatische und edaphische Faktoren gebunden waren als durch selektive biotische Beziehungen (auch wenn engere interspezifische Beziehungen von bestimmten Arten bekannt sind).
The females adopt in specific patterns according to age and species of the young. Parts of larvae are also accepted in a similar pattern indicating that chemosensory mechanisms may be involved. Depending on the relation between the age of the adopted and original larvae, the former complete their larval development in the marsupium or are lost upon moult of the female. Larvae which are not in an appropriate age stage to finish larval development in any particular marsupium are rarely accepted.
Adoption probably results from a larvae replacement behaviour which serves to inhibit loss of larvae- The females do not appear to clean their brood. There are further intensive interactions between larvae and females when fully developed larvae are released.
25 Mysidenspezies aus dem Sublittoral des Adriatischen und des Tyrrhenischen Meeres wurden über einen Zeitraum von fünf Jahren untersucht. Feldforschung wie auch Laborstudien wurden mit unterschiedlichen Methoden der Beobachtung, Aufsammlung, Markierung und Kultivierung der Organismen unternommen.
Die räumliche Verteilung der Mysiden war durch bathymetrische Muster, die Natur des Substrates, durch klimatische und edaphische Parameter und das Sozialverhalten charakterisiert, letzteres in Form der Schwarmbildung. Wachstum und Entwicklung zeigten Unterschiede je nach Spezies, Alter, Geschlecht, Erreichbarkeit von Nahrung, Jahreszeit und Temperatur. Abhängigkeiten der Populationsregulation von Dichte und Nahrungsverfügbarkeit konnten aufgezeigt werden. Die jahreszeitlichen Reproduktionszyklen zeigten deutliche Abhängigkeiten von Temperatur und Nahrungsverfügbarkeit. Die untersuchten Spezies waren überwiegend aktive Filtrierer. Diese Art von Ernährung war verbunden mit hoher migratorischer Aktivität, welche für die meisten Arten eine schwache Bindung an andere Organismen in den benthischen Lebensgemeinschaften zur Folge haben kann. Das stimmt damit überein, daß die untersuchten Mysiden sich zur Tageszeit im Allgemeinen als indigene Bewohner des bodennahen Pelagials erwiesen und daß sie geringere Spezifität zu benthischen Biotopen zeigten, an die sie eher durch klimatische und edaphische Faktoren gebunden waren als durch selektive biotische Beziehungen (auch wenn engere interspezifische Beziehungen von bestimmten Arten bekannt sind).
The effect of temperature is much stronger when compared with egg sizes and fits very well the Arrhenius equation. The temperature characteristic µ = 11822 corresponds to the periods of marsupial development in L. lingrura. In the laboratory at 16°C, the embryonic stage takes 31% of the total incubation time (mean of 14.9 days), the nauplioid stage 44%, and the postnauplioid stage 25%. At 22.5 °C the corresponding percentages are 27, 53, and 20%, respectively (total duration of 9.0 days). Similar percentages were found for the relative frequencies of larvae among broods in natural populations of nine species in the Adriatic and the Tyrrhenian Sea.
Egg or body sizes at hatching fron the egg membrane and at larval moults depend on the initial egg size and do not vary with the temperature. In nature, the premature loss of young from the brood pouch amounts to ≈ 11 %. The maternal moult cycle and the development of young are synchronized by moult inhibition.
Kurzfassung: Die küstennahe und benthopclagische Myside Leptomysis lingvura G.0. Sars wurde im Labor zu verschiedenen Jahreszeiten unter verschiedenen Temperaturbedingungen gehalten. Zusätzliche Experimente wurden an L. bürgii Bacescu durchgeführt. Bei konstanter Temperatur ist die Entwicklungszeit im Brutbeutel von der Eigröße signifikant abhängig. Die Beziehung ist mit der allometrischen Gleichung beschreibbar. Für L. lingvura wurde der allometrische Exponent αd =0.69 bei Bezugnahme auf Eidurchmesser, beziehungsweise αw, = 0.31 für Trockengewichte gefunden.
Der Effekt der Temperatur ist im Vergleich zur Eigröße erheblich stärker und ist mit der Arrhenius Gleichung sehr gut beschreibbar. Den Entwicklungszeiten von L. lingvura im Brutbeutel entspricht die Temperaturcharakteristik µ = 11822. Im Labor bei 16°C dauert die Embryonalperiode 31% der Inkubationszeit (im Mittel 14.9 Tage), das Nauplioidstadium 44% und das Postnauplioidstadiun 25%. Dem entsprechen hei 22.5 °C folgende Relativzahlen: 27%, beziehungsweise 53 und 20% (Gesamtdauer 9.0 Tage). Ähnliche Prozentsätze fanden sich in der Zusammensetzung natürlicher Populationen von neun Arten der Adria und des Tyrrhenischen Meeres.
Ei- und Körpergröße beim Schlüpfen aus der Eihülle, beziehungsweise bei larvalen Häutungen, sind von der anfänglichen Eigröße aber nicht von der Temperatur abhängig. Während die Bruten ausgetragen werden, gehen in der Natur annähernd 11 % der Jungen vorzeitig verloren. Die Synchronisation des elterlichen Häutungszyklus mit der Entwicklungsdauer der Bruten erfolgt mittels Häutungsinhihition.
The eggs of the first brood clutch are produced in the ovarian tubes most probably during three moult intervals; the subsequent clutches appear during one interval. The colour of the yolk differs between species and corresponds to the colour conditions of the prefered habitats. The eggs are extruded from the paired ovaries into a pair of egg sacs. Following this they are fertilized in the marsupium.
Marsupial development takes on the average 14.9 days at 16 °C. The young pass through three main stages. The following terminology is proposed: embryonic stage, nauplioid stage, and postnauplioid stage. During the embryonic stage development proceeds as is characteristic for Mysidacca. The embryonic period takes 4.6 days and is terminated by hatching from the egg membrane. The freshly hatched nauplioid corresponds in its most important features to the classic nauplius stage. Following this all body segments and appendages of the adults are formed without intervention of a moult. The nauplioid stage takes 6.6 days and ends with the first larval moult. The subsequent postnauplioid stage is liberated after 3.7 days from the brood pouch with the active help of the parent. Immediately after liberation the young undergoes a second larval moult to the juvenile stage which largely represents the adults.
The abdomen of the nauplioid stage bears setae and/or spines, and in some species a caudal furca. These features disappear completely at the first larval moult. In spite of the lack of the manca stage which occurs in the Isopoda and related orders, the Mysidacea have conserved plesioniorphic features which are not present in other orders of recent Peracarida: they hatch from the egg as a nauplius stage and in some species the nauplius carries a caudal (urea. The embryonic time ends at a less advanced stage than in the other orders.
Kurzfassung: Es gelang die schwärmende, küstennahe und benthopelagische Myside Leptomysis lingvura G. O. Sars mit gutem Erfolg im Labor aufzuziehen. Es konnte daher die Entwicklung von der Oogenese his zum Juvenilstadium verfolgt werden. Zusätzliche Untersuchungen wurden an fünf weiteren Arten der Unterfamilien Siriellinae und Mysinae durchgeführt.
Die Eier des ersten Brutsatzes werden wahrscheinlich während dreier Häutungsintervalle gebildet, die folgenden Bruten in jeweils einem Intervall. Die Farbe des Eidotters ist artweise verschieden und entspricht dein Farbmilieu der jeweils bevorzugten Standorte. Die Eier werden vom paarigen Ovar in ein Paar Eisäcke abgelegt und anschließend im Brutbeutel befruchtet.
Die Entwicklung im Brutbeutel erfordet im Mittel 14.9 Tage hei 16 °C. Es werden drei Hauptstadien durchschritten, für die folgende Terminologie vorgeschlagen wird: Embryonalstadium, Nauplioid und Postnauplioid. Die Entwicklung im Embryonalstadium erfolgt in der für Mysidaceen charakteristischen Weise. Die Embryonalperiode dauert 4.6 Tage und wird durch Schlüpfen aus der Eihülle abgeschlossen. Es ist nur eine Eihülle vorhanden. Das frischgeschlüpfte Nauplioid entspricht in den wichtigsten Merkmalen dem klassischen Naupliusstadium. In weiterer Folge jedoch werden alle Segmente und Extremitäten des Aduittieres angelegt, ohne daß eine Häutung erfolgt. Das Nauplioidstadium dauert im Mittel 6.6 Tage und endet mit der ersten Larvalhäutung. Das folgende Postnauplioidstadium wird nach 3.7 Tagen unter aktiver Hilfe des Muttertieres aus dem Brutbeutel freigesetzt und unternimmt sofort die zweite Larvalhäutung zum Juvenilstadium, welches den Erwachsenen weitgehend gleicht.
Das Abdomen des Nauplioids trägt Borsten und/oder Dornen und bei mehreren Arten eine caudale Furca. Diese Merkmale verschwinden bei der ersten Larvalhäutung vollständig. Trotz des Fehlens des Mancastadiums, welches bei den Isopoda und verwandten Ordnungen auftritt, haben sich in den Mysidaceen plesiomorphe Merkmale erhalten, die in anderen recenten Peracariden fehlen: sie schlüpfen als Naupliusstadium und der Nauplius trägt bei einigen Arten eine caudale Furca. Die Embryonalperiode endet in einem weniger fortgeschrittenen Stadium als bei den anderen Ordnungen.
25 species of Mysidacea were studied in the Adriatic and the Tyrrhenian Sea over a period of five years. The study was conducted in the field as well as in the laboratory using differing observation, sampling, staining, and culturing methods.
The spatial distribution is shown to be characterized by bathymetric patterns, character of the substrate, climatic and edaphic parameters, and social behaviour (swarming). Growth and time of development depends on species, age, sex, availability of food, season and temperature. There is evidence of food and density dependent population regulation. The seasonal cycles of reproduction correspond to the seasonal variations in food availability and temperature. The observed species are mainly active filter feeders. This mode of feeding is coupled with a high migrational activity, resulting in a weak relationship to the other organisms in the benthic community. This coincides with the finding that the observed Mysidacea are indigenous inhabitants of the near bottom pelagial (at daytime), and that they show less specificities toward the benthic biotopes, to which they seem to be tied more through climatic and edaphic factors than by biotic relations.
The whole procedure of copulation takes about one second or less where a spermatophore is introduced into the marsupium. The marsupial plates bear a special kind of setae with an armature of small spinules which work as a device for acceptance and fixation of spermatophores. These features of the marsupium are also present in Siriella jaltensis Czerniavsky, Anchialina agilis (G. O. Sars), and Hemimysis lamornae (Couch). After having copulated once or twice, the female probably does not respond properly to further mating partners so that the spermatophores are fixed outside the brood pouch.
The spermatophore is the first reported for the order Mysidacea. It consists of a soft tube-like membrane containing thousands of whip-like sperm cells. Fertilization proceeds in the marsupium following oviposition. A new transfer of sperm is necessary for each subsequent clutch of eggs.
The diurnal rhythm of release of young, of ecdysis, of mating, and of egg laying was observed in nature and corresponds to results obtained in the laboratory. The release of fully developed young starts shortly before sunset; this is followed by moulting and mating. The eggs are laid from one to six hours after sunset.
We have carried out growth measurements in a superficial bed of Posidonia oceanica (L.) Delile laying around the island of Ischia (Gulf of Naples).
Moreover, we have studied the structure of the epiphtytic communities of Microflora (Diatoms) and Macroflora along an age gradient.
Another way of approach to the problem was to investigate nutrient uptake in the plant and its epiphytes.
This issue, which is to be placed in the framework of « Posidonia Project u, is an analysis of epiphytic covering of Posidonia oceanica leaves, along a bathymetric gradient. To this purpose, we took samples along a transect at the depth of 3, 5, 10 e 20 meters, near Alghero (NW Sardina), following standard methodology. The covering was determined separately for epiflora and epifauna, making distinction between inner and outer side of the leaves and their arrangement in the single shoot. At the same time, we made a biometrical study of the leaves. In order to obtain a simultaneous representation of observation and variable points, two different techniques of multivariate analysis were used: 1° Principal Component Analysis (PCA), 2 Factorial RQ Analysis (RQA). The ordination patterns demonstrate a different covering strategy for epiflora and epifauna both in bathymetric gradient and in single leaves. These differences seem to express the effect of the most important environmental factors, such as bydrodynamism and illumination, which cause the benthic fauna zonation.
Recently Mauchline (1980) has reviewed the biology of mysidaceans and I have drawn freely on some of the data presented in his tables. He dealt with the broad field of the biology but did not go into so much detail as far as incubation is concerned. Nevertheless, some overlap in our studies appears to be inevitable. I have not included some important topics such as sex ratio, differential mortality of sexes, and growth, age, and numbers of moults at sexual maturity. For these fields of interest one should consult Mauchline's (1980) study.
GENERAL CONCLUSIONS FOR THE UNDERSTANDING
OF BREEDING BIOLOGY IN MYSIDACEANS
There are two basically different groups, semelparous and iteroparous mysidaceans. Differences are apparent not only in generation times and timing of breeding but also in the allometric relationships between parents and young. The latter differences appear to be due to the number of broods per se as in the case of semelparity there is neither the necessity nor the possibility of synchronizing development and production of subsequent broods. There is no doubt that semelparity is of advantage in high latitudes due to the low temperatures in combination with the short duration of the favourable season. It is, however, known also from the giant bathypelagic species G. ingens which probably lives in a relatively stable environment. Childress Price (1978) discuss the possible advantage of semelparity for this species and state. . . because of the greater stability of its habitat it can . . . concentrate all its reproductive effort on a single event. This may be much more energy efficient, since the reproductive individual can use a larger fraction of its energy in reproduction . . .. This remains speculative as long as there are no weight or energy measurements which compare broods and breeding females. Volumetric studies of Mauchline (1973) indicate that the meso- and bathypelagic species including G. ingens invest on the average the same fraction of body volume in reproduction as do epipelagic species.
In iteroparous mysidaceans the breeding biology is split into three highly different levels which involve differences (1) between latitudes, (2) between seasons (provided that there is a strong seasonal climate), and (3) between individuals.
Natality and relative fecundity, as defined above, both appear to be constant between latitudes but undergo strong seasonal variations. Natality increases with increasing individual size but, as far as is known, relative fecundity does not seem to vary with variations in size. Absolute fecundity expressed as numbers of young per brood increases with increasing latitudes in relation to temperature. At the favourable season absolute fecundity is high, but at or shortly before the onset of the unfavourable season, fecundity is low and largely independent of seasonal variations in body size and temperature. Brood sizes increase linearly, or possibly less than linearly, with individual body weight. In contrast to this, brood size increases with about the square root of weight between latitudes.
Egg weights increase with increasing latitudes in relation to temperature in about the same way as do brood sizes. Egg sizes may not vary between seasons in certain species or a species may produce larger winter eggs and smaller summer eggs. There seems to be no direct relation to temperature as the production of the larger eggs may start in early autumn at water temperatures as high as 20-25 °C, while on the other hand, the production of small summer eggs may start in late spring at about the same temperatures (pers. obs. on Leptomysis lingvura in the Gulf of Naples). There appears to be no correlation between egg sizes and individual parental body sizes.
As a consequence of the foregoing, the production of yolk per egg per incubatory day does not vary between latitudes and also not, as far as is known, between individuals. There may, however, be strong variations between seasons. Weight at attainment of maturity and brood weights, both increase between latitudes almost twice as steeply with increasing temperature than do brood sizes and egg weights. In temperate climates, summer animals are frequently smaller than winter ones, but similar frequently maximum sizes may be reached in spring. Similar relations may exist for brood weights. These increase about linearly with individual body weights. The same relation was found to exist between latitudes or species. Among seasons this relation is heavily `disturbed' by variations in brood weight due to minima or maxima in breeding intensity.
The key factor for the understanding of these relationships seems to be the temperature effect on incubation periods. It is strong between latitudes, but much weaker between seasons. There are no visible differences in the temperature response between individuals of L. lingvura (Wittmann, 1981b). There is a small effect of egg size on incubation periods which is about the same between latitudes and among individuals. Wittmann's (1981b) results indicate that this is also most likely between seasons. Each of three levels of breeding performance are supposed to be indicative of different adaptive significance. Between latitudes reproduction appears to be adaptive in order to compensate for the strong effects of temperature on incubation periods. Among seasons the seasonal variations of food supply and, as an outcome of these, variations of population levels seem to be of major significance. For individuals it may be of major importance that a given increase in body weight becomes transformed into a corresponding increase of individual reproductive fitness, expressed as production of young per incubatory day. This indirectly favours the capability of adapting population levels to ambient food levels.
L'étude de la fécondité des femelles de cinq espèces.(Leptomysis lingvura, L. posidoniae, L. gracilis, L. burgii, L. heterophila) a été entreprise à partir de matériel récolté en plongée dans divers secteurs de la Méditerranée occidentale. Il apparait clairement que le nombre d'embryons portés par ces femelles est directement corrélé à la taille de celles-ci. Au cours de l'année, ce nombre varie également, parallèlement aux modifications de la longueur moyenne des adultes (fonction sinusoidale dont l'amplitude dépend de l'espèce considérée).
La mortalité des embryons au cours de leur développement dans la poche marsupiale peut étre estimée par comptage du nombre moyen de chaque stade chez des femelles de taille similaire; cette mortalité est d'environ 12 %.
Enfin, à certaines saisons, et chez qertaines espèces, la présence d'un parasite (Copépode) dans le marsupium des femelles induit une fécondité nulle pour celles-ci, et réduit considérablement le potentiel reproductif des populations.