590 Tiere (Zoologie)
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The enigmatic ‘y-larvae’ (Thecostraca: Facetotecta) are microscopic marine planktonic crustaceans that were discovered more than a century ago, yet to this day their adults remain unknown. Despite occurring locally in large diversities, and therefore presumably being of ecological importance, only 17 species have been described globally, rendering it practically impossible to identify any y-larval specimen from any locality. The fact that species have been based on different life stages (nauplii and/or cyprids) further hampers identification. Y-larvae include many forms with planktotrophic (feeding) nauplii and even more with lecithotrophic (non-feeding) nauplii. At one coral-reef locality on the shore of Sesoko Island (Okinawa, Japan), extensive fieldwork in 2018 and 2019 confirmed an enormous taxonomic diversity of y-larvae there. Here, we present morphological diagnoses and an identification key for 34 lecithotrophic y-naupliar types (or morphospecies), which will correspond minimally to the same number of species when described. As a temporary measure, all are referred to by alphabetical parataxonomic designations, except for three that have been formally described already within the genus Hansenocaris Itô, 1985. To this should be added an additional 7–9 planktotrophic y-naupliar morphospecies, which are only treated briefly. Most often, y-larval taxonomy has been based on the cyprid stage, but the large morphological diversity of y-nauplii suggests that nauplii are at least as important for taxonomy. Lecithotrophic y-nauplii display a multitude of body shapes, the form-evolution of which is discussed here with reference to a recent molecular phylogeny of Facetotecta partly based on material from the same site. An indirect estimate of the relative abundances of all 34 lecithotrophic y-naupliar morphospecies is presented, based on laboratory-reared final-instar specimens. This treatment is intended as a step towards a proper taxonomy and a revised classification of Facetotecta, which will involve detailed descriptions of both nauplii and cyprids. Until such work progresses, the present overview of the y-naupliar fauna of a single Okinawan locality known to be a hotspot of y-larval diversity is offered as a baseline for further surveys of Facetotecta elsewhere in the Indo-West Pacific and beyond.
Several adult female monstrilloid copepods, collected in March 2022 from the protected reef area of Xcalak, on the southern part of the Mexican Caribbean coast, proved to belong to two undescribed species of Monstrilla Dana, 1849. They are described here as M. xcalakensis sp. nov. and M. annulata sp. nov., partly by use of scanning electron microscopy. Females of the two species are generally similar but differ in: (1) antennular segmental structure, (2) antennular armature and ornamentation, (3) structure and setation of the fifth leg, (4) number and modifications of the caudal setae, and (5) integumental ornamentation. Comparison with congeneric species revealed distinctive features for both species that support their status as new. These two species are interesting additions to the reef-dwelling monstrilloid copepod fauna of the Mexican Caribbean and confirm Monstrilla as the most diverse genus of monstrilloids in this area, now represented by nine species.
Three new species of the genus Pelodera Schneider, 1866 viz., P. indica sp. nov., P. adeeli sp. nov. and P. paratretzeli sp. nov. collected from dung beetles and P. cylindrica (Cobb, 1898) collected from soil samples, are described and illustrated. Pelodera indica sp. nov. is characterised by sexual dimorphism in anterior region, cupola-shaped tail with a spike; males having punctated, striated and lobed bursa with no genital papillae originating anterior to cloaca. Pelodera adeeli sp. nov. is characterised by coarsely annulated cuticle; relatively narrow stoma; tail conoid without spike; males with punctated, lobed bursa and nine pairs of genital papillae arranged in a 2/1+2+P+3+1 configuration. Pelodera paratretzeli sp. nov. is characterised by sexual dimorphism in anterior region, stoma wide with three well-developed metastegostomal denticles; tail cupola-shaped with a long spike; males having spicules fused distally up to 12–14% of spicule length; bursa peloderan, anteriorly closed and punctated with nine pairs of genital papillae arranged in a 3/2+P+3+1 configuration. Pelodera cylindrica is described with additional details. The comparative analysis as well as phylogenetic relationship of the species belonging to the coarctata group have been elaborated by incorporating scanning electron microscopic observations. Information on the biogeographical distribution has also been provided.
Two species of the genus Ophelina Örsted, 1843 (Annelida, Opheliidae) are reported from the coast of Kuwait (Arabian Gulf) after specimens collected in the intertidal and shallow subtidal, namely Ophelina arabica sp. nov. and Ophelina grandis (Pillai, 1961). The new species is mainly characterised by features of the anal tube, which is provided with about 25 annulations at each side; the ventral margins are fully fused while dorsal margins are fused at most of their length but are free at the distal end in the shape of a conspicuous incision; the posterior end is opened with free margins; the anal tube also lacks marginal papillae but bears a pair of basal papillae and an unpaired anal cirrus attached to ventral margin at mid-length. Ophelina grandis is reported for the first time in the Arabian Gulf; specimens are fully described and compared with similar species. A key for species of Ophelina in the Indo-Pacific, Southern Asia, Indo-Malay Archipelago and Australia, is also provided.
Six new species of Zaischnopsis Ashmead (Hymenoptera: Eupelmidae) from China are described, Zaischnopsis covid Jiang & Peng sp. nov., Zaischnopsis fuscolivida Tang & Peng sp. nov., Zaischnopsis lii Jiang & Peng sp. nov., Zaischnopsis pacis Jiang & Peng sp. nov., Zaischnopsis campaniformis Tang & Peng sp. nov., and Zaischnopsis zhongi Jiang & Peng sp. nov. All the new species are described and illustrated based on females, and partial mitochondrial cytochrome oxidase subunit I (COI) sequences are provided for the six new species as well as for the previously described Z. fumosa Peng & Xiang. Females of all the species of Zaischnopsis recorded from China are differentiated in a key.
Benthic samples were collected during two expeditions near the Antarctic Peninsula and in the South-Eastern Weddell Sea. During these studies, a new species of Ampharetidae Malmgren, 1867, Anobothrus konstantini Säring & Bick sp. nov., was found. Here we present a detailed description of this species. We used the traditional light microscope and scanning electron microscope (SEM) to identify and describe the diagnostic characters: a circular glandular band on segment 6; an elongate ridge between the notopodia on segment 12 and modified notochaetae on this segment; 16 thoracic, two intermediate and ten abdominal segments. For the first time, micro-computed tomography (micro-CT) was used for a species description of Anobothrus. Micro-CT provided information on the shape of the prostomium (Ampharete-type) and the arrangement of branchiae (four pairs in two rows, without a gap). In addition, we provide quantitative information on the environmental niche based on sediment parameters (chlorophyll a content, organic matter content, chloroplast equivalent, grain size) for the new Anobothrus species, relevant for, e.g., species distribution modelling. Finally, an identification key for all Anobothrus species is provided.
Based on samples collected during the BIOICE project off Iceland, four species of marine annelids belonging to the family Pectinariidae were identified: Amphictene auricoma (O.F. Müller, 1776), Cistenides granulata (Linnaeus, 1767), Cistenides hyperborea Malmgren, 1865 and Lagis koreni Malmgren, 1866. Taxonomic remarks and data on geographical and bathymetric distribution are presented. The distribution of each species off Iceland was evaluated and two patterns were defined: C. granulata and C. hyperborea were mainly found in waters off the northeast coast, while A. auricoma and L. koreni were found on the southern coast. Several body characters with taxonomic value in this family were reviewed under the stereo microscope and scanning electron microscope, with special emphasis on the neuropodial uncini. Remarks on these special chaetae are included in the diagnoses.
Ampharete oculicirrata sp. nov. (Annelida: Ampharetidae) is described from samples collected by the Joint Nature Conservation Committee and Marine Scotland Science, in the West Shetland Shelf NCMPA in the NE Atlantic. This species is characterised by a very small body size, thin and slender paleae, twelve thoracic and eleven abdominal uncinigers, presence of eyes both in the prostomium and the pygidium, the latter provided with a pair of long lateral cirri. The external micro-morphology of the new taxon was studied using scanning electron microscopy and compared with species described or reported from the North Atlantic. Two complementary keys to all species of Ampharete in the area are also provided.
Necropsies of Baltic grey (Halichoerus grypus) and ringed seals (Pusa hispida) presented a rare opportunity to study their acanthocephalan fauna. Both species hosted adults of three species of the genus Corynosoma Lühe, 1904, namely C. magdaleni Montreuil, 1958, C. semerme (Forsell, 1904) Lühe 1911 and C. strumosum (Rudolphi, 1802) Lühe 1904. A comparative morphological analysis of these three species of Corynosoma, combining both light and scanning electron microscopy, was performed for the first time. Sexual dimorphism in the size and shape of the trunk was observed in both C. magdaleni and C. semerme, but there was insufficient material to investigate this phenomenon in C. strumosum. Genital spines were not observed in any of the female acanthocephalans. Three possible explanations for the presence of genital spines in some females, but not others are (i) cryptic speciation, (ii) phenotypic variation and (iii) loss by extraction or shearing when the copulatory cap is released. Copulatory caps were observed on female C. semerme. The size and morphology showed considerable variability and all caps were strongly autofluoresecent.
The new genus Neodiplopeltula gen. nov. is proposed to accommodate those species from the genus Diplopeltula Gerlach, 1950 that possess the following morphological characters: amphids in the shape of an elongated loop, a well-developed subcylindrical stoma and outstretched ovaries. The genus Diplopeltula is considered genus inquirendum et incertae sedis. Four species placed in Neodiplopeltula gen. nov. are redescribed. The following taxonomic changes are proposed: Neodiplopeltula asymmetrica (Allgén, 1935) gen. et comb. nov.; Neodiplopeltula barentsi (Steiner, 1916) gen. et comb. nov.; Neodiplopeltula bathmanni (Jensen, 1991) gen. et comb. nov.; Neodiplopeltula cuspidiboja (Leduc, 2017) gen. et comb. nov.; Neodiplopeltula indica (Gerlach, 1962) gen. et comb. nov.; Neodiplopeltula intermedia (Gerlach, 1954) gen. et comb. nov.; Neodiplopeltula obesa (Nguyen Vu Thahn, Nguyen Thahn Hien & Gagarin, 2012) gen. et comb. nov.; Neodiplopeltula onusta (Wieser, 1956) gen. et comb. nov.; Neodiplopeltula ovalis (Ditlevsen, 1928) gen. et comb. nov. and Neodiplopeltula tchesunovi (Fadeeva & Mordukhovich, 2013) gen. et comb. nov. New synonyms include: Diplopeltis asymmetricus Allgén, 1935 and Diplopeltis ovalis Ditlevsen, 1928 are synonimised with Neodiplopeltula barentsi (Steiner, 1916) gen. et comb. nov.; Diplopeltula tchesunovi Fadeeva & Mordukhovich, 2013 is synonimised with Neodiplopeltula onusta (Wieser, 1956) gen. et comb. nov.; the male of Diplopeltula cuspidiboja Leduc, 2017 is synonimised with Neodiplopeltula barentsi gen. et comb. nov. and the female with N. bathmanni gen. et comb. nov. A key to the species of Neodiplopeltula gen. nov. is provided.