Thermopsis thermophila n. gen. n. sp. from hot springs in Nevada, U.S.A. (Crustacea, Ostracoda)

Thermopsis thermophila n. gen. n. sp., a new freshwater ostracod species is described from hot springs in Nevada, U.S.A. The animals were collected within a temperature range of 40–55°C. The new genus belongs to the Ostracoda Podocopida Cypridoidea Cyprididae Cypridopsinae.     

High cryptic diversity and persistent lineage segregation in endemic Romecytheridea (Crustacea,Ostracoda) from the ancient Lake Tanganyika (East Africa)

Ostracods form a substantial part of the endemic fauna of ancient lakes. Here, we have investigated the phylogenetic and phylogeographic patterns and genetic diversities of species of the endemic genus Romecytheridea from the Southern and Central part of Lake Tanganyika. We found that ostracod populations from four different localities are genetically highly differentiated from each other when analyzing the mitochondrial 16S region, while they are almost identical with genetic markers from the nuclear genome (D1-D2 from the large ribosomal subunit (LSU) and ITS). The criteria of the K/θ method for the evolutionary species concepts are fulfilled when analyzing 16S DNA sequence data, indicating that these populations are in fact different (cryptic) species with allopatric distribution. We discuss various hypotheses on how this high diversity could have originated. The complete lineage segregation can partly be explained by geographic isolation during periods of low lake level stands. But, other factors must have contributed to genetic isolation and speciation, as the two closest populations (Chimba and Katoto) from shallow parts of the Southern basin of Tanganyika are also geographically fully segregated.     

On the Cyprideis species flock (Crustacea, Ostracoda) in Lake Tanganyika, with the description of four new species

Four new species, belonging to three genera, of ostracods from Lake Tanganyika are described: Mesocyprideis nitida sp.nov., Romecytheridea belone sp.nov., R. plegma sp. nov. and Cyprideis loricata sp. nov. The Cyprideis species flock of Lake Tanganyika now consists of 17 formally described species (16 endemic) in 6 genera (4 endemic). The geographical and ecological distribution of the four species is briefly discussed and some supplementary remarks on the radiation of the Cyprideis species flock in Lake Tanganyika are offered.     

Aorella multiplex gen. et sp.n. a New Aorid (Crustacea, Amphipoda) from Fiji

Aorella multiplex gen. et sp.n. is described and figured. The species lives amongst algae and phanerogams on reef flats in Fiji. The species cannot readily be assigned to any known genus of Aoridae (sensu Myers 1981), and a new genus is here erected for its inclusion.     

Yamaguchia toyensis n. sp., n. gen. (Annelida, Clitellata, Lumbriculidae) from profundal Lake habitat in Japan

Yamaguchia toyensis n. sp., n. gen. is described from an oligotrophic caldera lake, Lake Toya, Hokkaido, Japan. Although the taxonomic affinities are unknown, the genus differs from all other Lumbriculidae in having the combination of testes and atria in X, a single, prosoporous male funnel per atrium, and spermathecae in XI. Unlike other Japanese lakes that have thus far been surveyed, Lake Toya supports abundant populations of lumbriculids in the profundal benthos.     

Argulus izintwala n. sp. (Crustacea: Branchiura) from Lake St Lucia,South Africa

During surveys of the fish parasites of Lake St Lucia on the coast of northern KwaZulu-Natal, specimens of an hitherto undescribed argulid were found on the skin of the kelee shad Hilsa kelee (Cuvier). This, only the fourth argulid species to be found in South African coastal waters, is here described as Argulus izintwala n. sp.     

Seasonally and spatial distribution of the ostracods of Lake Zwai, Ethiopia (Crustacea: Ostracoda)

SUMMARY. 1. Quantitative benthic samples were collected monthly between June 1984 and May 1985 from seven stations at various depths in Lake Zwai, one of the Ethiopian Rift Valley lakes, situated in the northern part of the Rift Valley. The most common species of ostracods were Limnocythere thomasi thomasi Martens (a subspecies endemic to Lake Zwai), Gomphocythere angutata Lowndes (common in, but restricted to. East Africa) and Darwinula stevensoni (Brady & Robertson) (cosmopolitan).
2. Absolute densities of all species varied considerably over the year. In all stations, there were population peaks during the two dry seasons, followed by as yet unexplained population crashes during the short and the long rains.
3. The three common species had different habitat preferences. Darwinula stevensoni avoids parts of the lake where temperatures rise high and both G. angulata and L. thomasi had a preference for sheltered habitats close to vegetation and/or for a specific grain size of the sediment (300–350 μm).     

Psammaspides williamsi gen.n., sp.n., ein Vertreter einer neuen Familie mesopsammaler Anaspidacea (Crustacea, Syncarida)

A new species of the order Anaspidacea, Psammaspides williamsi gen.n., sp.n., is described from Australia. It belongs to a family of its own, Psammaspididae fam.n. This family seems to bridge the gap between the Stygocarididae and the Anaspidacea. The new species was found in gravel along a stream in northern New South Wales extending the range of distribution of the Anaspidacea far beyond its known limits to the north. It is the first fully interstitial species within the Anaspidacea.

Zusammenfassung

Eine neue Art der Ordnung Anaspidacea, Psammaspides williamsi gen.n., sp.n. wird aus Australien beschrieben. Sie gehört zu einer neuen Familie, den Psammaspididae. Diese Familie scheint zwischen den Stygocarididae und den Anaspidacea zu vermitteln. Die neue Art wurde im Schotter eines Baches im nördlichen New South Wales entdeckt und dehnt das Verbreitungsareal der Anaspidacea weit über seine bisher bekannten Grenzen nach Norden aus. Es ist die erste echt mesopsammale Art innerhalb der Anaspidacea.     

Palerasnitsynus gen. n. (Trichoptera, Psychomyiidae) from Burmese amber

Palerasnitsynus ohlhoffigen. et sp. n. is described fromBurmese amber of late Albian (Lower Cretaceous) age. This is the first record of the family Psychomyiidae from Burmese amber, and the earliest fossil record of the family. The genus Palerasnitsynusgen. n. differs from all other known psychomyiid genera by the absence of fork III in the forewings.     

Ostracods (Ostracoda,Crustacea) from two freshwater lakes near Maarssen,The Netherlands

Summary In Lake Maarsseveen I (with the lowest trophic level) 15 ostracod species were collected, whereas 9 species were found in Lake Maarsseveen II.Physocypria kliei Schäfer, 1934, andCypridopsis obesa Brady and Robertson, 1869, are new to the Dutch fauna.     

A New Species of Ilyodromus Sars (Crustacea, Ostracoda) from the Philippines

The genus Ilyodromus Sars, 1895 is recorded for the first time in the Oriental Region. Ilyodromus lanaoensis sp. n. is described from Mindanao, the Philippines and compared with the other species of the genus for differential diagnosis.     

Salinity tolerance of Mytilocypris henricae (Chapman) (Crustacea,Ostracoda)

Salinity tolerance, and the effects of temperature upon it, of the Australian ostracod Mytilocypris henricae (Chapman) was determined in direct transfer experiments using adults. Animals were subjected to a combination of 11 salinities (ranging between 0.0 g · 1^–1 and 45.0 g · 1^–1) and 4 temperatures (10, 15, 20 and 25 °C). Survival was analysed using two statistical techniques: the logit linear model and the proportional hazards model. Results show that both salinity and temperature have a significant effect on survival, but there is no significant interaction between temperature and salinity.     

Sub-Decadal Resolution in Sediments of Late Miocene Lake Pannon Reveals Speciation of Cyprideis (Crustacea,Ostracoda)

Late Miocene "Lake Pannon" (~11.3 Ma) was a remnant of the Central Paratethyan Sea. Successive freshening and constantly changing environmental conditions, like oxygenation, nutrition and substrate led to a well-documented radiation in molluscs and ostracods. Among ostracods (small crustaceans), Cyprideis is one of the most common genera in "Lake Pannon", as well as in several other ancient lakes, showing numerous adaptations and speciations. Here, we present high-resolution data from an early transgression of "Lake Pannon" in the Eastern Styrian Basin (SE Austria). Mataschen clay pit is in the focus of geologic and paleontologic research since 20 years and its geologic and paleoecologic evolution is well-documented. We drilled five cores covering a ~2.3 m long section and completely sampled it in 5-mm thick intervals to reconstruct minute changes in the ostracod fauna over a transgression of a brackish water body. The dominant genus, Cyprideis, is represented by three species C. mataschensis, C. kapfensteinensis and C. ex gr. pannonica. Through morphometric analyses we highlight the variance of each taxon and suggest that there is no direct ecologic control on size or shape. Furthermore, we found a second, co-occurring morphotype of C. kapfensteinensis which is directly related to an elevation of salinities above 13 psu. The presence of two intermediate specimens between the two morphotypes in the sample directly below the first appearance of C. kapfensteinensis B leads us to the conclusion that we are facing a speciation event leading to four sympatric species of Cyprideis.     

Global diversity of ostracods (Ostracoda,Crustacea) in freshwater

There are close to 2,000 subjective species and about 200 genera of Recent non-marine Ostracoda. Together, Cyprididae (1,000 spp.) and Candonidae (c. 550 spp.) represent more than 75% of the extant specific diversity; the remaining 11 families comprise the other 25% of the species. The Palaearctic region has the highest absolute non-marine ostracod diversity, followed by the Afrotropical. The Australian region has the highest relative endemicity. About 90% of the species and 60% of the genera occur in one zoogeographical region only. This means that all the biological mechanisms which lead up to efficient dispersal and which are present in at least part of the non-marine Ostracoda (e.g. brooding, drought-resistant eggs, parthenogenesis) have not induced common cosmopolitan distributions in ostracods. Several habitats are hotspots for ostracod diversity and endemicity. For example, it appears that the ancient lakes hold up to 25% of the total ostracod diversity. Other speciation-prone habitats are groundwater, temporary pools and Australian salt lakes; in the latter two instances, cladogenesis has often been paralleled by gigantism. The present ostracod diversity results from 9 to 12 separate invasions of the non-marine habitat, starting about 400 Myr ago. Genetic diversity can be very different in different species, mostly, but not always, related to reproductive mode. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

The Ontogeny of Neonesidea oligodentata (Bairdioidea, Ostracoda, Crustacea)

This is the first detailed ontogenetic study of the appendages and carapace of a bairdioidean ostracod. This paper uses the development of the appendages and changes in the pore systems of the carapace through ontogeny to help determine the relationship between the Bairdioidea and other podocope groups. Neonesidea oligodentata has eight post-embryonic stages: one fewer than the Cypridoidea, Cytheroidea and Darwinuloidea. The first instar of N. oligodentata resembles that of the second instar of the Cypridoidea and Cytheroidea in terms of appendages, and it is postulated that there is an additional instar stage of N. oligodentata that molts within the egg. The general sequence of appearance of the limbs from instar A-7 onwards is similar to that of the Cypridoidea and Cytheroidea, but different from that of the Darwinuloidea. Like the Cypridoidea and Cytheroidea, N. oligodentata has a gap in its ontogenetic development during instar A-6, where no new Anlage is added. Pore system analysis of A-7 instars suggests that the Bairdioidea may be more closely related to the Cypridoidea than to the Cytheroidea.     

Two new species of Pseudocythere Sars (Crustacea,Ostracoda) from Britain and Norway

Two new species of the genus Pseudocythere Sars are described, one each from British and Norwegian waters respectively.