Seven new species and two new genera of Physocypria sensu latu (Crustacea, Ostracoda) from Brazilian floodplains.

We describe seven new species in two new genera of the Physocypria sensu latu clade (Cyclocypridinae) from three of the main Brazilian floodplains. Brasilocypria pea gen. et spec. nov. and Brasilocypria ricardopintoi gen. et spec. nov. occur in the Upper Paraná River floodplain and the South Matogrossense Pantanal, Claudecypria mesquitai gen. et spec. nov., Brasilocypria alisonae gen. et spec. nov. and Claudecypria rochei gen. et spec. nov. were found in the South Matogrossense Pantanal, and Brasilocypria lordi gen. et spec. nov. and Brasilocypria namiotkoi gen. et spec. nov. occur in the Amazon River floodplain. All new species here described were found as sexual populations. Generally, they have a short and suboval carapace, with the left valve overlapping the right valve on all sides, except for the dorsal side in some species. The morphology of the hemipenis and the prehensile palps, together with the shape of the valves, were the most important characters to distinguish the species. Size differences between species can be substantial. Several characters, such as the absence in all new species of the short accompanying seta of the five natatory setae on the antenna; the presence in all new species of a long seta next to the two a-setae on the first thoracopod, and the presence/absence or differences in length of specific setae on the second and third thoracopod, are relevant for the generic diagnoses. We also redefine Keysercypria Karanovic, 2011.

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.

On a new tribe, genus and species of Cypricercinae McKenzie, 1971 (Crustacea, Ostracoda, Cyprididae) from New Caledonia (Pacific Ocean).

The New Caledonian Archipelago is a hot spot for biodiversity and endemism. Here, we describe Lithocypris peyia gen. et spec. nov. Martens, Almeida & Higuti from a single locality (a lithotelma, or rockpool) on Grande Terre, the main island of the archipelago. The new genus belongs to the subfamily Cypricercinae and to the new tribe Lithocypridini trib. nov. based on the absence of a groove and anterior inner lists in the left valve, on several aspects of the chaetotaxy, of the prehensile palps and of the hemipenis, and on the fact that the Triebels Loop is situated in the dorsal branch of the attachment of the caudal ramus. Lithocypris gen. nov. can further be distinguished from the other genera in the subfamily by a combination of features: carapace elongated in lateral view and narrow in dorsal view, left valve with a weak ventral and posterior inner list only, antennule with both Wouters and Rome organs, maxillula with elongated and rectangular second palp segment and very short sideways directed bristles, first thoracopod with setae a, b and d present and with female palp short and plump, second thoracopod with setae d1 and d2 very short, third thoracopod with seta f missing and Zenker organ with a crown.

On a New Species of Pseudocypretta Klie, 1932 (Crustacea, Ostracoda) from the Neotropical Region, with a Discussion on the Position of the Genus.

Pseudocypretta amor sp. nov. (named after the carapace spots resembling the word "Love") is here described from all-female populations from the four major floodplains in Brazil. The new species is compared to the other two known species in the genus, P. maculata Klie (1932), the type species, and P. lineata Ma and Yu (2020). As the latter two species are thus far found exclusively in South East Asia and China, respectively, the present extension of the area of the genus to South America is considerable. Several morphological characters in this genus and species are discussed, especially the presence of marginal septa in the valves, the candonid type T3 with 3rd and 4th segment separated (candonid type) and the caudal ramus which is reduced to a flagellum (cypridopsine type) or is fully absent. Based on the combination of these and other characters, the genus Pseudocypretta is here transferred from the Cyprettinae to the tribe Cyprettadopsini in the Cypridopsinae, as it is closely related to the genus Cyprettadopsis Savatenalinton, 2020. The presence of the candonid type T3 in Cyprididae and Notodromadidae, where the T3 generally has a pincer-shaped tip by the fusion of the 3rd and the 4th segment, is further discussed.

On two new species of Cypricercus Sars, 1895 (Crustacea, Ostracoda) from Brazil with a discussion on the taxonomy of the genus.

We describe two new species of Cypricercus, Cypricercus alfredo sp. nov. and Cypricercus tiao sp. nov., and briefly redescribe the female of Cypricercus centrurus (Klie, 1940) from Brazilian floodplains. Both new species have the elongated carapace which is characteristic of the genus. Cypricercus alfredo sp. nov. was found as both sexual and asexual populations and has a posterior spine on the right valve and differs from the Brazilian C. centrurus by the position and the size of spine and the size and shape of the carapace. Cypricercus tiao sp. nov. was found as one asexual population only and lacks a posterior spine on the right valve. Cypricercus populations in Brazil mostly consist exclusively of asexual females, but some sexual populations and populations with mixed reproduction can also be found. This genus occurs primarily in the Southern Hemisphere, but some species can also be found in the southern part of North America and in India. We also present a re-appraisal of all species presently allocated to the genus, primarily based on original descriptions.