Six New Species of Fresh and Brackish Water Ostracods (Crustacea) from Yakushima, Southern Japan

Twelve species of brackish and freshwater ostracods were collected from the island of Yakushima in southern Japan. Six species, belonging to the genera Cypria, Dolerocypris, Stenocypris, Schellencandona and Paracypria, are new and are described herein. The genus Schellencandona is reported for the first time outside Europe. Although a wide range of apparently suitable habitats was sampled for ostracods across the island, all specimens were recovered from or near the coast; further inland yielded no ostracods. The freshwater habitats around the coast of the island consist of springs and rockpools at the top of the shore above most high tide levels.     

Sperm lengths of non‐marine cypridoidean ostracods (Crustacea)

Length measurements of sperms of 51 species of Cypridoidea ostracods were taken to supplement the paucity of ostracod sperm data in the published literature. The lengths of the posterior regions (carrying the mitochondria) and the thinner anterior regions were also measured when appropriate. Maximum lengths of sperms for individual species varied from 268 μm for Fabaeformiscandona velifera Smith and Janz, 2008 through to 11 787 μm for Australocypris robusta De Deckker, 1974; these lengths represent the shortest so far recorded for the superfamily and the longest ever recorded in ostracods, respectively. There appears to be only a loose relationship between taxonomy and sperm lengths. Species of the subfamily Candoninae generally have the shortest sperms compared with other subfamilies, but one Candoninae species, Candona altoides Petkovski, 1961, has sperms longer than some species of the families Cyprididae, Ilyocyprididae and Notodromadidae. The family Cyprididae showed the most variation, with sperms ranging from 1000 μm through to 11 787 μm in length. No hypothesis satisfactorily explains the origin of giant sperms in ostracods or the longevity of this trait through geological eras, and their existence remains enigmatic.     

Detection of Ehrlichia and Anaplasma DNA in Ixodes (Exopalpiger) trianguliceps Bir. ticks in Tyumen Province

This paper presents data of study (PCR with fluorescent hybridization probes) of Ixodes (Exopalpiger) trianguliceps Bir. collected from small mammals in the southern taiga forests of Tyumen Province. DNA of Ehrlichia and Anaplasma was detected in ticks of this species for the first time. Cases of mixed infection were also observed.     

Bromeliad ostracods pass through amphibian (Scinaxax perpusillus) and mammalian guts alive

During a study about bromeliad tadpoles (Scinax perpusillus), the ability of bromeliad ostracods (genus Elpidium) to pass unharmed through the tadpole gut was documented. Seven Elpidium were found alive inside a tadpole's digestive tract. Subsequent experiments demonstrated that Scinax tadpoles frequently ingest bromeliad ostracods, eliminating them unharmed in the faeces. Another laboratory experiment demonstrated these ostracods'ability to pass through a mammalian (mouse) gut alive. The consequences of this ability in ostracod ecology and evolution is discussed. Biotic and abiotic data from the bromeliads where the ostracods and tadpoles were collected are given.     

The ostracod fauna (Crustacea,Ostracoda) of the profundal benthos of Loch Ness

We report the results of quantitative and qualitative investigations of the ostracod fauna of the profundal benthos of Loch Ness, an oligotrophic lake in Scotland, UK. Six ostracod species were recorded from profundal samples: Candona angulata, C. candida, Cryptocandona reducta, Cypria ophthalmica, Cyclocypris ovum and Potamocypris smaragdina. In addition, Psychrodromus robertsoni was found in fish gut contents. The mean density of profundal ostracods was 262 individuals m², with an average Brillouin's Diversity of 0.7. A weak inverse relationship between fish body weight and the number of ostracods eaten is reported for Arctic charr, Salvelinus alpinus.     

Phoretic Behaviour of Bromeliad Annelids (<Emphasis Type="Italic">Dero</Emphasis>) and Ostracods (<Emphasis Type="Italic">Elpidium</Emphasis>) using Frogs and Lizards as Dispersal Vectors

The phoretic behaviour of ostracods (Elpidium bromeliarum) andannelids (Dero superterrenus) that inhabit tank bromeliads was studied. Our previous field observations had shown that bromeliad ostracods can be found attached to the skin of amphibians and reptiles that move among bromeliads, probably allowing the ostracods to colonise new tanks. In this paper, we present the first record of bromeliad annelids found attached to frogs moving among bromeliads in the field. We have also enlarged the database on bromeliad ostracods engaged in phoretic association with terrestrial vertebrates in three locations in southeastern Brazil. In our laboratory experiments bromeliad annelids show a strong significant tendency to climb onto papers that had been in contact with frog skin when compared with control papers, indicating a kind of chemically oriented behaviour. Bromeliad ostracods, on the other hand, attached themselves to treated and untreated papers with same frequency. When brought into contact with various species of frogs and lizards, the bromeliad annelids and ostracods both presented preference to attach themselves to frogs, but the annelids showed a stronger preference to attach to frogs and to avoid attachment to lizards. Another experiment demonstrated that bromeliad annelids are much more prone to dehydration than are ostracods. We suggest that the chemically oriented behaviour presented by bromeliad annelids toward frogs could diminish the risk of death by dehydration during the transport among bromeliads due to the moist characteristic of frog skins.     

Spinicaudatans and ostracods (Crustacea) from the Montceau Lagerstätte (Late Carboniferous, France): morphology and palaeoenvironmental significance

Spinicaudatans and ostracods form two components of the diverse arthropod fauna from the Montceau Lagerstätte (Stephanian, France). Spinicaudatans are represented by Montcestheria orri gen. and sp. nov. and Euestheria feysi sp. nov., and ostracods by a single species, Carbonita sp. aff. salteriana (Jones, 1862). Allied forms such as Montcestheria sp. aff. orri, Montcestheria sp. and Euestheria cebennensis (Grand'Eury, 1890), all from coeval localities in France, are also described. Montcestheria gen. nov. has carapace features, external (possibly sexual) dimorphism, preserved soft parts (e.g. appendages, gut) and resting eggs similar to those of Recent spinicaudatans, suggesting comparable lifestyles, reproductive strategies and feeding modes. Detailed anatomical comparisons are made with Cyzicus tetracerus from Recent ephemeral freshwater ponds. The ostracods belong to the Superfamily Carbonitoidea, which is a recurrent component of Carboniferous non‐marine biotas. Spinicaudatan‐rich assemblages typically occur in several Westphalian–Stephanian Lagerstätten (including Montceau) and localities from Europe and North America, where freshwater conditions prevailed, indicating that the group had already colonized continental waters by the Late Carboniferous. Similarities with the fauna from Recent temporary freshwater ponds (e.g. low diversity/high density spinicaudatan‐ostracod populations, synchronous spinicaudatan populations developing from resting eggs, high diversity/low density insects, amphibians) suggest the presence of temporary or ephemeral aquatic environments at Montceau as part of a complex limnic ecosystem. Flooding may have been the main driving force by which faunal and floral elements drifted away from their respective biotopes into the depositional areas, thus explaining the co‐occurrence of terrestrial (e.g. myriapods, scorpions, plants), amphibian and aquatic (e.g. conchostracans and syncarids from temporary and permanent settings, respectively) elements in fossil assemblages.     

The ontogeny of appendages and carapace of Neonesidea schulzi (Ostracoda: Bairdiidae) from the Red Sea coast,Egypt

The ostracod genus Neonesidea is broadly distributed in shallow marine waters. The ontogeny of the N. schulzi (Bairdiidae) is described in detail by studying the development of the appendages and variations in carapace form, size and structure. Neonesidea schulzi has eight post-embryonic instars, and a gap in its ontogenetic development during instar A-6, where no new Anlage is added. The Anlagen of the copulatory organs and the forked terminal claw of second antenna appear in the seventh (A-1) instar, and the first thoracic legs of podocopid ostracods are shown to descend from the thoracic region. For the first time in ostracods, observations of moulting from sixth and seventh instars are presented.     

Effects of an Ostracod (Cypris pubera) on the Rotifer Keratella tropica: Predation and Reduced Spine Development

This study investigates two different effects of an ostracod on a rotifer. The rotifer Keratella tropica and the ostracod Cypris pubera were cultured on the alga Cryptomonas erosa. Adult ostracods (2.2 mm body length) significantly reduced the population growth rate (r day^–1) of K. tropica from 0.42 to 0.13. Individuals of this size ingested live rotifers and produced fecal pellets with rotifer loricas. Smaller ostracods (both 0.59 and 1.61 mm body lengths) did not affect K. tropica 's population growth rate. Surprisingly, C. pubera significantly inhibited spine development in K. tropica. Rotifers cultured with juvenile, non‐predatory ostracods had similar lorica lengths but right and left posterior spines that were 10 and 30% shorter, respectively. The spine reduction induced by the ostracod kairomone is in striking contrast to the spine elongation induced in this rotifer by kairomones from copepods, cladocerans and Asplanchna. In shallow ecosystems, large ostracods that swim in the plankton may be important predators of rotifers. In addition, the presence of ostracods in plankton communities may be one of many factors affecting rotifer spine development. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Silurian bolbozoids and cypridinids (Myodocopa) from Europe: pioneer pelagic ostracods

Abstract: Bolbozoid and cypridinid myodocope ostracods from France, the Czech Republic and Sardinia consist of four genera (one new: Silurocypridina) and at least ten species (eight new: Bolbozoe acuta, B. rugosa, B. parvafraga, Parabolbozoe armoricana, Silurocypridina retroreticulata, S. variostriata, S. calva and Calocaria robusta). They have a functional design, palaeogeographical distribution, depositional setting and faunal associates that suggest that they were swimmers in the water column, living in dim light, relatively deep environments, above near bottom dysoxic/anoxic conditions. These myodocope faunas include some possible pelagic species sensu stricto, with widespread palaeogeographical (transoceanic) distribution, and some species that occupied hyperbenthic niches and were capable of making short incursions to the sediment to scavenge on carrion. These data support the model that Silurian myodocopes were pioneer pelagic ostracods.     

An invaded invader: high prevalence of entocytherid ostracods on the red swamp crayfish <Emphasis Type="Italic">Procambarus clarkii</Emphasis> (Girard, 1852) in the Eastern Iberian Peninsula

The American red swamp crayfish Procambarus clarkii (Girard, 1852) was introduced in 1973 into the Iberian Peninsula for commercial purposes. As a result of both the expansion from the Iberian Peninsula and, probably, further introductions in other European countries, now it is widely distributed throughout much of Europe. The ecological impacts of this invading crayfish have received increasing attention, but nothing is known about its symbiotic entocytherid ostracods outside the American continent. The present survey has examined more than 200 crayfishes from 12 localities distributed over a wide area of Eastern Spain. Entocytherid ostracods were extracted from individual crayfishes and they were identified, counted, assigned to developmental instars and sexed. In all the study locations but one, we found at least one crayfish individual infected by entocytherid ostracods and the species determined was the same in all cases: Ankylocythere sinuosa (Rioja, 1942). The number of ostracods on individual P. clarkii varied notably in relation to crayfish size and also differed significantly among sampling sites. The crayfish size effects on ostracod densities might be related to the amount of resources and to the crayfish age and moulting frequency affecting ostracod distribution and population structure. In addition, the spatial variation in ostracod densities could also be related to site-specific habitat traits and the variability of crayfish population dynamics. Our study represents the first citation of an alien entocytherid species in Europe and demonstrates its wide distribution in the Iberian Peninsula. Further research is needed to know the potential effects of this ostracod species on the ecology of P. clarkii and of native species, with implications on the management of this aquatic invader.     

An example of intralacustrine evolution at an early stage: the freshwater ostracods of the Miocene crater lake of Steinheim (Germany)

I present the findings of two detailed studies on Steinheim lake ostracods carried out over the last eight years. The 178 samples studied cover a combined section about 30 m thick, comprising the whole sequence of seven planorbid beds. Of the 53 species found, 44 occur in the basic sediment layers, the kleinibeds. In contrast, all of the subsequent beds contain 16 species, and only seven species withstood the extinction at the kleini–steinheimensis boundary.This may be mainly due to the loss of littoral habitats brought about by a constantly increasing lake level, as the majority of the species in the kleinibeds were shallow water dwellers. Long-term lake level fluctuations are considered the most important external factor of the post-kleini period. Density fluctuations of the ostracods Pseudocandona steinheimensis and Potamocypris gracilis broadly reflect these water level fluctuations. At the beginning of the sulcatusperiod, when the lake level was very high, some species show morphological changes in their carapaces. During this time Leucocythere immigrata split into the daughter species L. sieberi and L. esphigmena. In the following trochiformis period, when the water level was lowest, the most curious carapace sculptures appear. The morphological changes detected, however, cannot simply be interpreted as ecophenotypic. The speciation event in Leucocythere, the non-recolonization with ubiquitous species during the low water level stage (trochiformis period), as well as the types of morphological changes indicate mainly evolutionary processes, as also the planorbid molluscs prove. Moreover, ostracods and planorbids show convergent evolutionary patterns. Compared with data on ostracod speciation in ancient lakes, the ostracod assemblage of Lake Steinheim seems to be a good palaeontological example of intralacustrine evolution at an early stage.     

Distribution and community structure of Ostracoda (Crustacea) in shallow waterbodies of southern Kenya

The current study presents the ostracod communities recovered from 26 shallow waterbodies in southern Kenya, combined with an ecological assessment of habitat characteristics. A total of 37 waterbodies were sampled in 2001 and 2003, ranging from small ephemeral pools to large permanent lakes along broad gradients in altitude (700–2 800 m) and salinity (37–67 200 µS cm^?1). Between 0 and 12 species were recorded per site. Lack of ostracods was associated with either hypersaline waters, or the presence of fish in fresh waters. Three of the 32 recovered ostracod taxa, Physocypria sp., Sarscypridopsis cf. elizabethae and Oncocypris mulleri, combined a wide distribution with frequent local dominance. Canonical correspondence analysis on species–environment relationships indicated that littoral vegetation, altitude, surface water temperature and pH best explain the variation in ostracod communities. Presence of fish and water depth also influence species occurrence, with the larger species being more common in shallow waterbodies lacking fish. Based on Chao’s estimator of total regional species richness, this survey recovered about two-thirds (60–68%) of the regional ostracod species pool. Scanning electron micrographs (SEM) of the valve morphology of 14 ostracod taxa are provided, in order to facilitate their application in biodiversity and water-quality assessments and in palaeoenvironmental reconstruction.     

Distribution and taxonomy of shallow marine Ostracods from Northern Socotra Island (Indian Ocean) - Yemen

Forty-seven species belonging to 30 genera of ostracods have been identified from Recent shallow marine sediments collected along the northern coastline of the island of Socotra (Indian Ocean). The systematics and distribution of these ostracods are discussed. Three genera, Loxoconcha, Bosasella, and Xestoleberis are found to have high species diversity. The species Loxoconcha ghardaqensis, Moosella striata are best documented in the Red Sea and Gulf of Aden while Kotoracythere inconspicua and Triebelina sertata were found to be the most widespread species. The fauna shows a close affinity to other ostracod assemblages of the Indo-Pacific region, East African coast and Red Sea.     

Non-marine Ostracoda (Crustacea) of Banat district in Serbia

In order to enrich the knowledge on ostracods in Serbia, field work was carried out in the central and southern part of the Banat district during 2002 and 2003. Samples from the collection of the Institute of Zoology, Faculty of Biology in Belgrade were also examined. Altogether, 133 samples were investigated. In this research, 23 ostracod species were found. Most of them have a Palaearctic distribution. Ilyocypris decipiens, Bradleycypris obliqua and Tanycypris pellucida are new to the faunas of Serbia and Montenegro, as is the subfamily Cypricercinae. Three species were found again after several decades, including a new and stabile population of Candona natronophila Petkovski, 1969 . The most frequent species were Cypridopsis vidua and Physocypria kraepelini. Statistical analysis of ostracod communities and their relations to measured ecological variables is also given.     

Diel vertical migration and endogenous swimming rhythm in Asterope mariae (Baird) and Philomedes interpuncta (Baird) (Crustacea Ostracoda Cypridinidae)

Among the benthic ostracods Asterope mariae and Philomedes interpuncta, the adult males emerge at dusk from the benthos and swim straight up to the surface, where they soon concentrate in the neustonic realm. The migration starts when the irradiance is almost 1 W cm^-2 and the maximal density occurs at the surface when the light has reached 0.005 W cm^-2, before it is completely dark. The migration ends <1 h later and very few animals are observed in the water column later in the night. Upward migration does not result from a positive phototaxis to dim light, but rather from a strong negative geotaxis and an increase in kinesis or swimming activity which occur at around 1 W cm^-2. This activity is induced both by the end of the diurnal period of photoinhibition and by an endogenous circadian rhythm. This rhythm could be clearly observed in both species from the recordings made during up to 2 weeks in constant darkness. The length of the period was roughly 24 h (24 h 3 min in Asterope, 23 h 10 min i Philomedes). The timing of the activity phase in total darkness varied depending on the post-capture history of the experimental animals, especially on the time of onset of the experiment. The adaptive advantage of this rapid diel vertical migration may be a question of feeding, but this may also increase the nocturnal dispersal of the reproductive males, and thus promote the reproduction of the species.      

Biostratigraphy and palaeobiogeography of the Cambrian genusHipponicharion (Ostracoda)

The bradoriid genusHipponicharion Matthew, 1886 is one of the oldest known Cambrian ostracods. Until now, five species have been documented and another three taxa have been tentatively assigned to one or another species.Hipponicharion has been recorded from Poland, Germany, Morocco as well as from Canada and Great Britain.Hipponicharion hispanicum n. sp. represents the first Cambrian ostracod documented from Spain.Hipponicharion taidaltensis n. sp., formerlyH. aff.geyeri Hinz-Schallreuter, 1993 andH. elickii n. sp., formerlyH. cf.eos sensuElicki, 1994 have also been restudied in this paper.Hipponicharion seems to be restricted to the Acadobaltic Province sensuSdzuy (1972). The systematic relationships of the Bradoriida, which is controverse, is briefly outlined, emphasizing close affinities to the Ostracoda.      

The species composition and distribution of ostracods (Crustacea,Ostracoda) in rockpools on islands in the Kandalaksha Bay of the White Sea

A total of 15 species of ostracods of 7 genera and 3 families of the suborder Podocopa Sars have been recorded in rockpools of the Kandalaksha Bay in the White Sea. Among them, Potamocypris pallida Alm is a new species for the fauna of Russia. Data on species composition and the dominant complex and ecological features of ostracods which inhabit waters of rockpools are presented.     

Selective predation by Lestes (Odoiiata, Lestidae) on littoral microcrustacea

• 1 Two experimental approaches were used to examine the predation risk of six littoral cladoceran and ostracod species to two size classes of the damselfly Lestes sp. Behavioural observations were conducted in a 2–1 arena and predation rate experiments in 1–1 jars in the laboratory.
• 2 Behavioural observations revealed that attack and capture efficiencies by Lestes were higher on smaller cladocerans (Polyphemus and Ceriodaphnia) than on other taxa. Small Lestes had little success ingesting the small ostracod Cypridopsis, whereas larger Lestes captured and ate it easily.
• 3 Predation-rate experiments showed that Lestes has a clear preference for smaller cladocerans over both a large cladoceran (Simocephatus) and all three ostracods (Cypricercus, Cyclocypris, and Cypridopsis). Most Lestes were unable to consume the larger Cypricercus.
• 4 Attack rates and predation rates were highly variable among individual predators.
• 5 These data indicate that damselfly larvae are size selective and consume all but very large cladocerans more readily than ostracods.