Papers by Fernando Pardos
Zoologischer Anzeiger, Nov 1, 2022
Organisms Diversity & Evolution, Jan 6, 2021
Size-latitude trends in the meiobenthic phylum Kinorhyncha, commonly known as mud dragons, have b... more Size-latitude trends in the meiobenthic phylum Kinorhyncha, commonly known as mud dragons, have been explored in oceans worldwide. Generalized least squares regression was used to assess relationships between size and latitude, as well as between size, latitude, and two selected environmental variables that exhibit latitudinal gradation: the sea surface temperature and the net primary productivity. Different structures of spatial autocorrelation and potential confounding factors, such as the species richness and the number of kinorhynch records that could affect latitudinal gradients, were also addressed. In addition, generalized mixed models were used to determine the influence of the phylogeny on body size. Size-latitude relationships of Kinorhyncha were commonly found globally, as well as for particular geographic regions (hemispheres and/or coastlines), with important differences between taxonomic groups. These size-latitude trends were heterogeneous and implied the influence of the latitude itself, environmental variables, and phylogeny. These facts indicate that a single underlying process is not likely to explain the observed relationships but a complex interaction of several macroecological patterns both present and past. Perhaps, the inclusion of future new reports, conducted in undersampled areas, may shed some light on the matter and reveal more generalized size-latitude patterns. Nevertheless, it is also likely that broadly generalizable size-latitude relationships may not exist in meiofaunal communities.
Zoological Journal of the Linnean Society, Oct 19, 2019
Allometry determines relevant modifications in metazoan morphology and biology and is affected by... more Allometry determines relevant modifications in metazoan morphology and biology and is affected by many different factors, such as ontogenetic constraints and natural selection. A linear mixed model approach and reduced major axis regression were used to explore evolutionary interspecific allometric trends between the total trunk length and the lengths of the segments and spines in the phylum Kinorhyncha at three taxonomic levels: the whole phylum, the class and the family. Statistically significant results were found in all the trunk segments, meaning that these body units grow proportionally correlated with the body, contrary to the results obtained for the spines. Developmental and morphophysiological constraints could lead to negative allometry in the first and last segments, because these body regions in kinorhynchs are essential to the implementation of some of the main biological functions, such as feeding and locomotion. The differential arrangement of cuticular appendages between the taxonomic groups considered seems to cause different evolutionary trends, because positive allometry may appear if a segment requires more space to accommodate a large number of organs and appendages, and vice versa. The presence of sexual dimorphism could also define positive allometry of a segment, owing to the need to harbour the sexually dimorphic appendages and their associated structures.
Invertebrate Biology, Mar 1, 2021
A state of alert was declared on March 14, 2020, throughout Spain in order to bring the health em... more A state of alert was declared on March 14, 2020, throughout Spain in order to bring the health emergency caused by the COVID-19 pandemic under global control. The Royal Decree proclaimed by the government abruptly blocked most daily activities, including all faceto-face lessons at the university. Under this scenario, universities were obliged to adapt their educational systems to these exceptional circumstances for the remainder of the 2019-2020 academic year. In our case, as university teachers, it was a challenging time as we had to adapt our teaching to an online version very quickly. As invertebrate zoology teachers, we focus on animals that students are unfamiliar with (Russell, 1996), and we felt that full online learning was not meaningful enough for them. Theoretical concepts are easier to understand and grasp when combined with practical experience (Balcombe, 2000; Jacobs & Moore, 1998). Therefore, after the end of the spring course and in order to foresee a similar situation for the following course in 2020-2021, we decided to develop a new tool to adapt our teaching, learning, and assessment to the current exceptional situation. Planning for the academic year 2020-2021 needed to take into account the need for physical distance between students and the constant disinfection of surfaces. This meant limited seating capacity in the laboratories and the need to disinfect materials or samples between use, which made it impossible or impractical to share specimens or instruments for manipulating and observing samples (e.g., tweezers, microscopes, stereomicroscopes). The course we teach is Invertebrate (non-Arthropods) Zoology (called "InA" by the students) and is taught as part of the Master of Science in Zoology degree at Complutense University of Madrid (Spain), the only MS in Zoology in Spain, so students from different regions enroll. It is therefore aimed at university graduates who have chosen to specialize in zoology and whose previous zoological knowledge comes from a 1-year general zoology course during their undergraduate studies. Within the master's program there are courses covering the zoology of arthropods and vertebrates as well as more specific courses on techniques, research
Panace@: Revista de Medicina, Lenguaje y Traducción, 2001
Biogeographia, Jul 15, 2022
We present a data set on marine mites (family Halacaridae) in European waters. The data set gathe... more We present a data set on marine mites (family Halacaridae) in European waters. The data set gathers all the published records of marine mites from the North European Seas, Lusitania, Mediterranean Sea and Black Sea marine provinces, all belonging to the temperate North Atlantic geographical realm. The database includes 3006 records collected from 260 original publications. For each record, the dataset provides complementary taxonomic, geographical, and ecological information, as well as remarks regarding the sampling methods used in each study. We use this dataset to briefly discuss potential knowledge gaps and biases across marine regions and habitats. We hope these data will provide a baseline for further studies in biogeography and ecology.
Marine Biodiversity, Sep 14, 2022
Polymetallic nodule fields represent a large reservoir of undiscovered biodiversity that becomes ... more Polymetallic nodule fields represent a large reservoir of undiscovered biodiversity that becomes particularly evident for meiobenthic organisms, the smallest-sized faunal group. Knowledge gaps are especially noticeable for the generally low-density metazoan groups, such as Kinorhyncha, the so-called mud dragons. Using both morphological and genetic (metabarcoding) approaches, we provide a general overview and comparison of the diversity of kinorhynchs collected during nine sampling campaigns (2016-2019) that targeted abyssal environments in several contract areas for exploration in the Clarion-Clipperton Fracture Zone (CCZ) and in the Peru Basin. Our findings from morphological analyses reveal a highly diverse mud dragon community, with 16 species present in the CCZ. Of these, 12 appear in the German contract area, including three new species described in the present contribution: Echinoderes delaordeni sp. nov., Echinoderes sanctorum sp. nov., and Echinoderes zeppilliae sp. nov. Furthermore, metabarcoding data of the kinorhynch community gathered from the area is provided, together with the geographic distribution of the known species stated per contractor area, including new records and still undescribed species. Most of the identified species in the CCZ seem to have a wide distribution, with Echinoderes sp.4 being the most common and abundant species with a distribution spreading across the CCZ and also present in the Peru Basin. Metabarcoding analyses targeting the V1V2 hypervariable region of the 18S gene from the 253 stations of the CCZ revealed 14 amplicon sequence variants (ASVs) belonging to Kinorhyncha with grade values higher than 98% detected at 15 different stations within six different areas along the CCZ. Concurring with morphology, the family Echinoderidae was the most diverse as the genus Cephalorhyncha had five ASVs, followed by Echinoderes with four ASVs. Semnoderes, however, showed the widest spread ASV, being detected at six stations. In the CCZ, the metabarcoding data showed there were no shared ASVs between the CCZ areas as well as the highest number of uniques, which was 11. Our morphological study showed a low number of specimens inhabiting nodules (surface/ crevices), suggesting that specific kinorhynch species do not typically inhabit the nodules in addition to the surrounding sediment. Keywords Meiofauna. Kinorhynchs. German contract area. Metabarcoding. Deep sea This article is registered in ZooBank under http://zoobank.org/ 1B354AA1-DB24-41FA-9CF7-1D608C3705A2 This article is a contribution to the Topical Collection Biodiversity in Abyssal Polymetallic Nodule Areas Communicated by S. Kaiser
Zoologischer Anzeiger, Sep 1, 2019
A new species of Kinorhyncha, Triodontoderes lagahoo sp. nov., is described from Tobago Island, C... more A new species of Kinorhyncha, Triodontoderes lagahoo sp. nov., is described from Tobago Island, Caribbean Sea (western Atlantic Ocean) from a coastal, sandy habitat using both light and scanning electron microscopy. The species is characterized by the presence of middorsal acicular spines on segments 1-11 (that on segment 10 crenulated in males), laterodorsal crenulated spines on segment 10 only in males, lateroventral acicular spines on segments 3-4 and 6-8 (lateroventral spines also on segment 10 in females), lateroventral cuspidate spines on segments 5 and 9, lateral accessory acicular spines on segments 5 and 9, lateral accessory cuspidate spines on segment 8, ventrolateral acicular spines on segment 2 and ventrolateral cuspidate spines on segment 2. Females furthermore possess short papillae in ventrolateral position on segment 8 and ventromedial position on segment 9. The absence of cuspidate spines in lateral accessory position on segment 6 easily distinguishes T. lagahoo sp. nov. from the single known congener, T. anulap. Moreover, also the arrangement of female papillae and sensory spots differ between the species. The finding of a new species of Triodontoderes in the Caribbean Sea is the first report of the genus for American waters and the Atlantic Ocean since its original description. Additionally, a dichotomous key for identification of the family Zelinkaderidae to species level, as well as systematic remarks on some morphological characters of the new species are included herein.
Diversity and Distributions, May 4, 2023
AimThe interplay between distribution ranges, species traits and sampling and taxonomic biases re... more AimThe interplay between distribution ranges, species traits and sampling and taxonomic biases remains elusive amongst microscopic animals. This ignorance obscures our understanding of the diversity patterns of a major component of biodiversity. Here, we used marine Halacaridae to explore whether differences between marine provinces can explain their distribution patterns or if differential sampling efforts across regions prevent any macroecological inference. Furthermore, we test if certain functional traits influence their distribution patterns.LocationEurope.ResultsWhereas geographical variables provided a better explanation for differences in species composition, sampling effort and distance from marine biological stations accounted for the majority of differences in European Halacaridae richness. Species occurring in more habitats showed broader geographical ranges and accumulated more records. Species traits like generalism affected the distribution of halacarid species.Main ConclusionsWe propose that the sampling effort of halacarid mites in Europe might be explained by two different cognitive biases: the convenience of selecting certain sampling localities compared to others and the tendency of zoologists to scrutinise habitats where their target organisms are more common.
Zootaxa, Jun 9, 2023
The scientific life of Robert P. Higgins was devoted to meiofauna, microscopically small animals ... more The scientific life of Robert P. Higgins was devoted to meiofauna, microscopically small animals living in aquatic sediments from the intertidal to hadal depths worldwide. He focused on the taxonomy, life-history, and ecology of the marine taxa Kinorhyncha, Tardigrada, and Priapulida and co-discovered the phylum Loricifera. He improved the methods for studying meiofauna and contributed significantly to spreading knowledge about these animals. Aspects of his life are described and lists of his publications, taxa described, contributions to science, and honours received are provided.
Zoologischer Anzeiger, Nov 1, 2016
Panace@: Revista de Medicina, Lenguaje y Traducción, 2004
lengua de traducción», celebrado en Toledo del 19 al 22 de mayo del 2004 (<www.toledo2004.net/ind... more lengua de traducción», celebrado en Toledo del 19 al 22 de mayo del 2004 (<www.toledo2004.net/index.php>).
Turkish Journal of Zoology, Nov 15, 2021
In a very recent contribution, the first Mediterranean record of the genus Sphenoderes was made f... more In a very recent contribution, the first Mediterranean record of the genus Sphenoderes was made from Zelinka's original sampling site in the Gulf of Naples (Sørensen and Herranz, in press). However, the East Mediterranean, and in particular the Turkish kinorhynch fauna, has been left much more unexplored, and was basically representing a blank spot on the map until less than half a decade ago. Yamasaki et al. (2018a, 2018b) explored the deeper parts of the East Mediterranean, and described two species, Echinoderes multiporus Yamasaki et al., 2018a and E. pterus Yamasaki et al. 2018b. All remaining East Mediterranean kinorhynchs are also part of the Turkish fauna. The first contributions about the Turkish kinorhynch fauna were published by Sönmez et al. (2016), Ürkmez et al. (2016) and Yıldız et al. (2016), soon to be followed by Yamasaki and Durucan (2018) and Sørensen et al. (2020). The present contribution gives a summary of the exploration of kinorhynchs along the Turkish coast (Figure 1) and provides data from eight newly sampled localities along the Turkish west and south coasts. 2. Materials and methods 2.1. Sampling and processing Samples were collected by FD in the period from 2017 through 2020, either by SCUBA, snorkelling or by hand at shallow depths (see dates and localities in Table 1). Meiofauna was extracted by stirring the sediment in seawater, and subsequently decanting it through a fine mesh. The extracted meiofauna was sorted under a Nikon SMZ stereo microscope, and kinorhynchs were picked up and fixed in 4% formalin. Specimens for light microscopical studies (LM) were dehydrated through a graded series of glycerine, and
Invertebrate Biology
The ecosystem formed by the marine flowering plant Posidonia oceanica is a biodiversity reservoir... more The ecosystem formed by the marine flowering plant Posidonia oceanica is a biodiversity reservoir and provides many ecosystem services in coastal Mediterranean regions. Marine meiofauna is also a major component of that biodiversity, and its study can be useful in addressing both theoretical and applied questions in ecology, evolution, and conservation. We review the meiofaunal diversity in the meadow ecosystem of P. oceanica by combining a literature review and a case study. First, we gathered records of 672 species from 71 published studies, as well as unpublished sources, highlighting 4 species exclusive to this ecosystem. Eighteen of those studies quantified the spatial and temporal changes in species composition, highlighting habitat‐specific assemblages that fluctuate following the annual changes experienced by these meadows. Hydrodynamics, habitat complexity, and food availability, all three inherently linked to the seagrass phenology, are recognized in the literature as the ...
Zoologischer Anzeiger, 2019
Several meiofaunal samples from the central and lower Gulf of California were studied. Four new s... more Several meiofaunal samples from the central and lower Gulf of California were studied. Four new species of kinorhynchs, Cristaphyes fortis sp. nov., Higginsium mazatlanensis sp. nov., Cephalorhyncha teresae sp. nov. and Echinoderes xalkutaat sp. nov., are described herein. Cristaphyes fortis sp. nov. may be distinguished from its most similar congeners by its more strongly developed pachycycli and ball-andsocket joints and the presence of unpaired paradorsal setae on segments 2, 4 and 6, two pairs of ventrolateral setae on segment 5, one pair of ventrolateral setae on segments 2-4, 6-7 and 10, and one pair of ventromedial setae on segments 8-9. Higginsium mazatlanensis sp. nov. is easily distinguished from its congeners by the combined presence of subdorsal setae only on segment 1 and lateroventral setae only on even segments. Cephalorhyncha teresae sp. nov. is unique within the genus by the presence of acicular spines in middorsal position on segments 4, 6 and 8, in sublateral position on segment 7 and in lateroventral position on segments 8 and 9, as well as tubes in subdorsal position on segment 2, and in lateroventral position on segment 5. Moreover, this species has primary pectinate fringes of segments 2-7 bearing a tuft of elongated spinous projections in middorsal position, which is unique among its congeners. Echinoderes xalkutaat sp. nov. belongs to a group of Echinoderes characterized by possessing type 2 glandular cell outlets in subdorsal, laterodorsal, sublateral and ventrolateral positions on segment 2, together with middorsal spines on segments 4-8, lateroventral spines on segments 6-9 and lateroventral tubes on segment 5, but the arrangement of the remaining type 2 glandular cell outlets (in midlateral position on segment 5, in sublateral position on segment 8 and in laterodorsal position on segment 10) and the cuticular composition of segment 11 (one tergal and two sternal plates) allow its morphological differentiation.
Zoologischer Anzeiger, 2023
Taxonomic studies of the phylum Kinorhyncha follow a standardised structure, which is extremely u... more Taxonomic studies of the phylum Kinorhyncha follow a standardised structure, which is extremely useful in many aspects, such as making it easier to read and compare the different species descriptions. Nevertheless, the morphological measurements methods, essential for formal description of species, may differ according to the authors. In the present contribution, we propose a standardised method of taking and representing the measurements, with the aim of obtaining comparable and repeatable morphometric results. Additionally, we propose an online repository to make the measurements accessible to all researchers in the same format, facilitating future comparisons and studies. Finally, a glossary that compiles and defines all the measurements that may be included in Kinorhyncha descriptions is presented.
REDUCA (Biología), Oct 6, 2011
Acantocéfalos. Algunos de estos grupos de animales están relacionados con el parasitismo.
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Papers by Fernando Pardos