Department of Botany and Zoology

A West African species of gecko, Tarentola parvicarinata Joger (Gekkonidae), collected in the Niokolo Koba National Park in East Senegal is a new host species for the nematode Parapharyngodon echinatus (Rudolphi, 1819). Fifty one specimens of P. echinatus were studied under a light microscope and thirteen specimens were studied for the first time by a scanning electron microscope. The main differences between P. echinatus and other African species, especially Parapharyngodon micipsae , were in the shape of annules on body cuticle, broad lateral alae and their terminations, the shape of the distal extremity of the spicule and number of outgrowths at the anterior cloacal lip. For the purposes of DNA characterization, partial sequence of the small subunit ribosomal RNA gene (SSU rRNA) was obtained from two specimens of P. echinatus. This is the first published sequence of a species from the family Pharyngodonidae.

This study, based on a morphometric approach for identification of the nematode parasite Parapharyngodon micipsae (Seurat 1917), reports the first record of P. micipsae in a West African species of gecko, Tarentola parvicarinata Joger 1980 (Gekkonidae), collected in the Niokolo Koba National Park, Senegal. Specimens of P. micipsae were examined under a light microscope and for the first time with a scanning electron microscope. The main differences between males of P. micipsae and similar African species (P. margaritiferi Hering-Hagenbeck 2001, P. kenyaensis Bursey & Goldberg 2005, P. meridionalis (Chabaud & Golvan 1962)) are in the shape and length of spicule, number and distribution of caudal papillae, outgrowths morphology, cloaca-tail distance and host. In the case of females, P. micipsae differs significantly from similar species mainly in oesophagus length, anus-tail end distance and egg size. Morphological differences between P. micipsae and P. echinatus (Rudolphi 1819) males in lateral alae, form of distal end of spicule and morphology of outgrowths were confirmed as stable features.

ascaridoid nematodes referable to Brevimulticaecum heterotis were recorded from the intestine of the african bonytongue, Heterotis niloticus (cuvier) (arapaimidae, osteoglossiformes), from the Mare simenti in the Niokolo Koba National Park, East senegal and from Kosti, sudan. their examination using light microscopy and for the first time both environmental scanning electron microscopy and scanning electron microscopy revealed some previously unreported morphological features and made possible a detailed redescription of this species. The most important finding is the presence of dentigerous ridges on the inner edges of the lips, which confirms the attribution of this species to Multicaecum Baylis, 1923, where it was originally placed, and not to Brevimulticaecum Mozgovoy in skryabin, shikhobalova et Mozgovoy, 1951 where it had subsequently been transferred. a key to Brevimulticaecum and Multicaecum species is provided. Multicaecum heterotis is the first species of the genus to be sequenced. Partial sequences of the small ribosomal subunit (18s) and internal transcribed spacer 2 region (its2) of nuclear ribosomal DNa (rDNa) have been analysed and compared with other nematode species.

First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopy. Larvae of both species are characterised by the presence of a dorsal cephalic tooth, four submedian cephalic papillae and a pair of amphids, and by the elongate tail with several terminal digit-like processes. The latter formations probably serve for the attachment of larvae to the substrate in water when the larvae attract copepod intermediate hosts by their movements; these structures, especially their numbers, may be of taxonomic importance in camallanid nematodes.

Scanning electron microscopy was used to study the female surface morphological characteristics of the mouth opening (lips and such adjacent structures as amphids, papillae and chitinous ribbed flaps), caudal area (vulva, anus), and eggs with filaments on poles of the pharyngodonid species Cithariniella khalili Petter, Vassiliadès et Troncy, 1972, obtained from Synodontis frontosa Vaillant at Lake Turkana in north-western Kenya.

First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopy. Larvae of both species are characterised by the presence of a dorsal cephalic tooth, four submedian cephalic papillae and a pair of amphids, and by the elongate tail with several terminal digit-like processes. The latter formations probably serve for the attachment of larvae to the substrate in water when the larvae attract copepod intermediate hosts by their movements; these structures, especially their numbers, may be of taxonomic importance in camallanid nematodes.

During a survey of species diversity and ecology of selected West African vertebrates in the Niokolo Koba National Park, Senegal, two Chamaeleo senegalensis Daudin, 1802 (Chamaeleonidae) were collected and examined for parasites. A new species, Oochoristica koubeki n. sp., anoplocephalidian cestode of the genus Oochoristica Lühe, 1898 is described from the intestine of this host. The new species is related to O. theileri Fuhrmann, 1924; O. theileri Fuhrmann, 1924 f. major Baer, 1933; O. celebensis Yamaguti, 1954 and O. rostellata Zschokke, 1905 var. agamicolla Dollfus, 1957. All the forenamed species share characteristic strobila with proglottids wider than long. Oochoristica koubeki n. sp. differs from these species in different proportions of scolex, cirrus sac, ovarium and vitellarium, further differences are in number of testes and presence of reinforced genital atrium. Only O. theileri shares two last mentioned features, however it differs in shape of testes (rounded) and in di...

Notothenioid fish were collected in the coastal part of the James Ross Island (Antarctica) mainly during Austral summer in 2012. In this paper, we report the list of species records and their basic biometric measurements as a reaction to missing ichthyofaunal investigation of this particular area. Collected fishes belong to the families Nototheniidae (Trematomus bernacchii Boulenger, 1902; T. eulepidotus Regan, 1914; T. newnesi Boulenger, 1902; Gobionotothen gibberifrons (Lönnberg, 1905); Notothenia coriiceps Richardson, 1844) and Bathydraconidae (Gymnodraco acuticeps Boulenger, 1902).

During the Czech Antarctic expedition 2014, 102 fish of six species (Trematomus hansoni, T.bernacchii, T. newnesi, Notothenia coriiceps, Parachaenichthys charcoti, Pagothenia borchgrevinki) were examined for parasites. The fish were caught in the Prince Gustav Channel (depth about 5–25 m) off the Johann Gregor Mendel Station on the James Ross Island. Altogether 7,925 metazoan parasites were found, which were identified to individual groups (usually classes). The most abundant were nematode larvae (prevalence 97.0 %, mean abundance 32.7 larvae/per fish), followed by acanthocephalans, especially larvae of species of Corynosoma (76.5%, 14.9) and monogeneans (77.5%, 13.0). Cestodes (Diphyllobothriidea, Tetraphyllidea) were represented by larval stages whereas trematodes only by adults. Our preliminary data may help in future studies on fish parasites in Antarctica because they indicate the most abundant groups of parasites occurring in notothenioid fish.

Invasive species are a major threat to biodiversity. In Madagascar, one quarter of freshwater fish fauna consist of introduced species. The introduction of non-native species affects native biota by means of direct interactions but also through indirect interactions including those mediated by parasites, as parasites are usually co-introduced with their hosts. Almost nothing is known about the parasites co-introduced with their fish hosts into Madagascar and their potential impact on native endemic fish fauna. We studied the metazoan parasites of native and introduced cichlid fishes (and some non-cichlids) in the northern part of Madagascar. Using parasite data we evaluated the effect of fish introduced from mainland Africa on native Malagasy cichlid fauna. We documented the co-introduction into Madagascar of parasite species from mainland Africa and also probably from Eurasia. Malagasy cichlids and some other species living in sympatry with non-native cichlids acted as competent hosts for generalist parasites and also for host-specific parasites of African mainland cichlids. However, African mainland cichlids were not susceptible to infection by parasites specific to Malagasy cichlids. The different compositions of parasite communities and infection parameters in endemic and non-native cichlids in the regions investigated may be potentially explained by the different sources and timings of fish introductions. In addition, native endemic parasite fauna even seem to be outcompeted by introduced parasites, which cross the barriers of host specificity. The transmission of non-native parasites associated with the introduction of non-native freshwater fishes may represent a serious risk to endemic freshwater fish and parasite fauna in Madagascar.

1Although invasions by alien plants are major threats to the biodiversity of natural habitats, individual habitats vary considerably in their susceptibility to invasion. Therefore the risk assessment procedures, which are used increasingly by environmental managers to inform effective planning of invasive plant control, require reliable quantitative information on the extent to which different habitats are susceptible to invasion. It is also important to know whether the levels of invasion in different habitats are locally specific or consistent among regions with contrasting climate, flora and history of human impact.2We compiled a database of 52 480 vegetation plots from three regions of Europe: Catalonia (Mediterranean–submediterranean region), Czech Republic (subcontinental) and Great Britain (oceanic). We classified plant species into neophytes, archaeophytes and natives, and calculated the proportion of each group in 33 habitats described by the European Nature Information System (EUNIS) classification.3Of 545 alien species found in the plots, only eight occurred in all three regions. Despite this large difference in species composition, patterns of habitat invasions were highly consistent between regions. None or few aliens were found in environmentally extreme and nutrient-poor habitats, e.g. mires, heathlands and high-mountain grasslands. Many aliens were found in frequently disturbed habitats with fluctuating nutrient availability, e.g. in man-made habitats. Neophytes were also often found in coastal, littoral and riverine habitats.4Neophytes were found commonly in habitats also occupied by archaeophytes. Thus, the number of archaeophytes can be considered as a good predictor of the neophyte invasion risk. However, neophytes had stronger affinity to wet habitats and disturbed woody vegetation while archaeophytes tended to be more common in dry to mesic open habitats.5Synthesis and applications. The considerable inter-regional consistency of the habitat invasion patterns suggests that habitats can be used as a good predictor for the invasion risk assessment. This finding opens promising perspectives for the use of spatially explicit information on habitats, including scenarios of future land-use change, to identify the areas of highest risk of invasion.Although invasions by alien plants are major threats to the biodiversity of natural habitats, individual habitats vary considerably in their susceptibility to invasion. Therefore the risk assessment procedures, which are used increasingly by environmental managers to inform effective planning of invasive plant control, require reliable quantitative information on the extent to which different habitats are susceptible to invasion. It is also important to know whether the levels of invasion in different habitats are locally specific or consistent among regions with contrasting climate, flora and history of human impact.We compiled a database of 52 480 vegetation plots from three regions of Europe: Catalonia (Mediterranean–submediterranean region), Czech Republic (subcontinental) and Great Britain (oceanic). We classified plant species into neophytes, archaeophytes and natives, and calculated the proportion of each group in 33 habitats described by the European Nature Information System (EUNIS) classification.Of 545 alien species found in the plots, only eight occurred in all three regions. Despite this large difference in species composition, patterns of habitat invasions were highly consistent between regions. None or few aliens were found in environmentally extreme and nutrient-poor habitats, e.g. mires, heathlands and high-mountain grasslands. Many aliens were found in frequently disturbed habitats with fluctuating nutrient availability, e.g. in man-made habitats. Neophytes were also often found in coastal, littoral and riverine habitats.Neophytes were found commonly in habitats also occupied by archaeophytes. Thus, the number of archaeophytes can be considered as a good predictor of the neophyte invasion risk. However, neophytes had stronger affinity to wet habitats and disturbed woody vegetation while archaeophytes tended to be more common in dry to mesic open habitats.Synthesis and applications. The considerable inter-regional consistency of the habitat invasion patterns suggests that habitats can be used as a good predictor for the invasion risk assessment. This finding opens promising perspectives for the use of spatially explicit information on habitats, including scenarios of future land-use change, to identify the areas of highest risk of invasion.

Habitats vary considerably in the level of invasion (number or proportion of alien plant species they contain), which depends on local habitat properties, propagule pressure, and climate. To determine the invasibility (susceptibility to invasions) of different habitats, it is necessary to factor out the effects of any confounding variables such as propagule pressure and climate on the level of invasion. We used 20 468 vegetation plots from 32 habitats in the Czech Republic to compare the invasibility of different habitats. Using regression trees, the proportion of alien plants, including archaeophytes (prehistoric to medieval invaders) and neophytes (recent invaders), was related to variables representing habitat properties, propagule pressure, and climate. The propagule pressure was expressed as the proportion of surrounding urban and industrial or agricultural land, human population density, distance from a river, and history of human colonization in the region. Urban and industrial land use had a positive effect on the proportion of both archaeophytes and neophytes. Agricultural land use, higher population density, and longer history of human impact positively affected the proportion of archaeophytes.

In European phytosociology, variable plot sizes are traditionally used for sampling different vegetation types. This practice may generate problems in current vegetation or habitat survey projects based on large data sets, which include relevés made by many authors at different times. In order to determine the extent of variation in plot sizes used in European phytosociology, we collected a data set of 41 174 relevés with an indication of plot size, published in six major European journals focusing on phytosociology from 1970 to 2000. As an additional data set, we took 27 365 relevés from the Czech National Phytosociological Database. From each data set, we calculated basic statistical figures for plot sizes used to sample vegetation of various phytosociological classes.

Question: What are the main broad-scale spatial and temporal gradients in species composition of arable weed communities and what are their underlying environmental variables? Location: Czech Republic and Slovakia. Methods: A selection of 2653 geographically stratified relevés sampled between 1954-2003 was analysed with direct and indirect ordination, regression analysis and analysis of beta diversity.

Variables determining the number of native and alien plants on arable land in Central Europe are identified. Species richness of 698 samples of weed floras recorded in the Czech Republic in plots of a standard size of 100 m 2 in 1955-2000 was studied in relation to altitudinally based floristic region, soil type, type of cultivated crop, climatic variables, altitude, year of the record, crop cover and height, and human population density in the region. Vascular plant species were classified into native and alien, the latter divided in archaeophytes, introduced before AD 1500, and neophytes, introduced after this date. The use of minimal adequate models in the analysis of covariance allowed determination of the net effects of mutually correlated environmental variables. Models for particular species groups explained 33-48% of variation in species numbers and 27-51% in proportions; however, explanatory variables affected native species, archaeophytes, and neophytes differently. The number and proportion of neophytes increased in 1955-2000, whereas the number of native species and archaeophytes declined (in archaeophytes more slowly in the warm than in the moderate to cool altitudinal floristic region). In warm and dry regions and on dry soils, where most archaeophytes find optimum conditions, fewer native species are able to persist in weed communities than in colder and wetter regions. Archaeophytes respond like neophytes to some variables (climate, seasonal development of crop) and alternatively like native species to other variables (increasing agricultural intensification through time, human population density). Archaeophytes are common in old crops introduced with the beginning of agriculture (cereals), but are poorly represented in relatively recently introduced crops (rape, maize), where neophytes are most numerous. These patterns reflect the history of plant invasions in Central Europe. Neolithic agriculture, introduced from the Near East in the sixth millenium BC, brought archaeophytes with crops and, by creating intense and continuous propagule pressure and imposing new agricultural management, facilitated their invasion. By contrast, the crops introduced during the past five centuries and their specific agrotechnical management have supported spreading of other weed species, mainly invaders from overseas.

Aim: Concentration of species occurrences in groups of classified sites can be quantified with statistical measures of fidelity, which can be used for the determination of diagnostic species. However, for most available measures fidelity depends on the number of sites within individual groups. As the classified data sets typically contain site groups of unequal size, such measures do not enable a comparison of numerical fidelity values of species between different site groups. We therefore propose a new method of measuring fidelity with presence/absence data after equalization of the size of the site groups. We compare the properties of this new method with other measures of statistical fidelity, in particular with the Dufrêne-Legendre Indicator Value (IndVal) index. Methods: The size of site groups in the data set is equalized, while relative frequencies of species occurrence within and outside of these groups are kept constant. Then fidelity is calculated using the phi coefficient of association. Results: Fidelity values after equalization are independent of site group size, but their numerical values vary independently of the statistical significance of fidelity. By changing the size of the target site group relative to the size of the entire data set, the fidelity measure can be made more sensitive to either common or rare species. We show that there are two modifications of the IndVal index for presence/absence data, one of which is also independent of the size of site groups. Conclusion: The phi coefficient applied to site groups of equalized size has advantages over other statistical measures of fidelity based on presence/absence data. Its properties are close to an intuitive understanding of fidelity and diagnostic species in vegetation science. Statistical significance can be checked by calculation of another fidelity measure that is a function of statistical significance, or by direct calculation of the probability of observed species concentrations by Fisher's exact test. An advantage of the new method over IndVal is its ability to distinguish between positive and negative fidelity. One can also weight the relative importance of common and rare species by changing the equalized size of the site groups.