A checklist of Recent non-marine ostracods (Crustacea: Ostracoda) from Thailand, including descriptions of two new species

On Caledromusrobinsmithi, a new genus and species of Psychrodromini Martens, 2001 (Crustacea, Ostracoda, Herpetocypridinae) from New Caledonia (Pacific Ocean)

The New Caledonian Archipelago is a hot spot for biodiversity and endemism. Whereas popular groups such as birds and plants are well-studied, invertebrate groups such as ostracods remain ill-known. Here, Caledromusrobinsmithigen. et sp. nov. is described from a single locality on 'Grande Terre', the main island of the archipelago. The new genus belongs to the Psychrodromini, one of the four tribes in the subfamily Herpetocypridinae (family Cyprididae). Caledromusgen. nov. can be distinguished from all other herpetocypridinids by a combination of the following factors: the absence of marginal septa in both valves, the mildly developed marginal valve structures, the small Rome organ on the A1, the total reduction of the five natatory setae on the A2, the rectangular second palp segment of the Mx1, the broad and asymmetrical palp on the female T1, the absence of additional postlabyrinthal coils in the Hp and the seta Sp of the CR which is a fixed spine. Because of the close similarity to the genus Psychrodromus, the new genus is thought to have Palaearctic affinities, contrary to other ostracod species in New Caledonia, which are either circumtropical or with Australian zoogeographical connections.

Three new species of non-marine ostracods (Crustacea, Ostracoda) from small water bodies of northern China

Three new species, Pseudocandonacheni sp. nov., Cyclocyprispangi sp. nov., and Tonnacyprisrectangularis sp. nov., collected from northern China, are described in this study. Pseudocandonacheni, of the compressa group, is difficult to be distinguished from other members of the same group by carapace morphology alone, but can be readily recognised by the structure of the hemipenis comprised of a long lobe a, distally inflated lobe h, and exteriorly pointed lobe b, as well as thick trunks of the male fifth limb endopodites. Cyclocyprispangi, despite its similarity in carapace morphology to its congeners, can be identified based on the morphology of the hemipenis, which bears a slender, slightly curved lobe h, and an S-shaped process accompanying lobe b, in addition to the rectangular trunk of the male fifth limb endopodite. On the other hand, Tonnacyprisrectangularis, described on the basis of females only, can be distinguished from other Tonnacypris Diebel & Pietrzeniuk, 1975 representatives by its distinct sub-rectangular carapace alone. Other differences include the length of the swimming setae, the length of the distal claws on the second antennae, and the morphology of the pincer organ on the seventh limb. This study contributes to the poorly known extant non-marine ostracod fauna of Inner Mongolia and Beijing, and generally to the central-eastern Palaearctic region. In addition, the known distribution range of Tonnacypris is extended eastwardly by T.rectangularis. The valve-morphology data are useful for identifying fossil/sub-fossil representatives.

A New Species of Pseudostrandesia Savatenalinton and Martens, 2009 (Ostracoda, Crustacea) Collected from Two Pet Shops in Central Japan: an Alien Species?

An undescribed species of freshwater ostracod belonging to the genus Pseudostrandesia Savatenalinton and Martens, 2009 was collected from two pet shops in the Kanto region of central Japan. This species, herein named Pseudostrandesia tenebrarum sp. nov., is similar to four species previously reported from Southeast Asia, but can be distinguished by carapace and appendage features. It is the second species of the genus for which males are known. Of the nine previously described species in the genus, one is exclusively known from Turkey, and the others are found in Southeast Asia and the vicinity, one of which is also recorded in India and east China. There are two scenarios to explain the existence of Pseudostrandesia tenebrarum sp. nov. in pet shops in Japan: it is either native to Japan but has yet to be discovered in its natural habitat, or it is an alien species, perhaps unwittingly imported with plants or fish for the pet trade. We review the likelihood of both scenarios, and conclude that although there is insufficient evidence to be sure, it is potentially an alien species in Japan. The most likely origin is Southeast Asia, as evidenced by its close morphological resemblance to particular Southeast Asian species. Juveniles as well as adults were recovered, indicating that this species is reproducing in the pet trade, supporting the notion that it has invasive potential to areas outside of its natural range. The description and report of this species highlights a possible introduction of an alien species to Japan, and facilitates further monitoring.