Artem Y. Sinev

Alona brandorffi sp. n. (Crustacea: Anomopoda: Chydoridae) – a new species from Brazil, related to A. verrucosa Sars, 1901

Alona brandorffi sp. n, related to A. verrucosa Sars, 1901 is described from Boa Vista, Brazil. Parthenogenetic females and males of A. brandorffi were studied. Examination of trunk limbs of A. brandorffi reveals several unusual modifications in structure, unique for the genus, such as very short setae on endites 2 and 3 of limb I, peculiar IDL setae, limb II with scrapers 7–8 with reduced distal part and only six, instead of seven setae in the filter plate, limb IV with only three, instead of four, setae on the inner lobe. The relationships and place of A. brandorffi within the genus Alona are discussed.

Notes on morphology and taxonomic status of some North American species of the genus Alona Baird, 1843 (Cladocera: Anomopoda: Chydoridae)

Detailed morphology of three North American species of the genus Alona Baird, 1843: A. bicolor Frey, 1965, A. circumfimbriata Megard, 1967 and A. setulosa Megard, 1967 was studied for the first time. The taxonomic status of these species is now clarified. A. bicolor belongs to the costata-group. Unlike to other species of the group, it demonstrates strong adaptation to benthic habitats - incl. thick carapace, a elongated rostrum and reduced eye. A. circumfambriata is a member of rectangula-group, and its closest relative is the tropical A. monacantha Sars, 1901, differing in morphology of postero-ventral angle of valves and exopodite of limb III. A. setulosa has numerous characters in common with the species of the pulchella-group, but the relationship is more distant than in two other discussed species.

Extremalona timmsi gen. nov., sp. nov., a new cladoceran (Cladocera: Anomopoda: Chydoridae) from an acid saline lake in southwest Western Australia

A new species of Cladocera, Extremalona timmsi gen. nov., sp. nov., was found in acid saline lakes in the southwest of Western Australia. Extremalona gen. nov. belongs to the Coronatella-branch of Aloninae, but differs from all members of the group by the oval body with small high-set head (tip of rostrum located at half-height of the body), the exopodite III with uniform, well-developed setae 4–6 and male antennule with six lateral and nine terminal aesthetascs, and by numerous other characters. In our opinion, Extremalona gen. nov. is one of the ancestral genera of the Coronatella-branch of Aloninae, sharing numerous common features with the elegans-group of Alona s.l. Our data confirm a high level of endemism in Australian Chydoridae and Cladocera in general.

Revision of the pulchella-group of Alona s. lato leads to its translocation to Ovalona Van Damme et Dumont, 2008 (Branchiopoda: Anomopoda: Chydoridae).

The pulchella-group of Alona s.l. (Cladocera: Anomopoda: Chydoridae) is transferred to Ovalona Van Damme et Dumont, 2008, and an emended diagnosis is provided. Ovalona meridionalis (Sinev, 2006) is removed from Ovalona due to differences in thoracic limb morphology. At the moment, Ovalona consists of 17 species, and is the largest natural genus of Aloninae. A key for the world fauna and diagnosis for all species is provided. The morphology of O. nuragica (Margaritora, 1971) is studied for the first time. The position of Ovalona within subfamily Aloninae and the distribution of the genus are discussed.

Redescription of Alona macracantha Smirnov and Timms, 1983 and its assignment to Maraura gen. nov. (Cladocera: Anomopoda: Chydoridae)

A morphological investigation of the Australian cladoceran Alona macracantha Smirnov and Timms, 1983 revealed numerous differences from all other species of the genus and prompted its assignment to Maraura gen. nov. Main diagnostic characters of the new genus include an elongated rostrum, Monospilus‐like postabdomen, long, sinuous basal spine of postabdominal claw, absence of accessory seta of limb I, thickened scrapers 3 and 5 of limb II, and exopodites of limb III–V fused with the main body of the limb. The affinities and taxonomic position of this rare Australian endemic are discussed.

Redescription of Alona labrosa Vasiljeva & Smirnov, 1969 (Chydoridae, Anomopoda, Branchiopoda)

The morphology of the Baikalian Alona labrosa Vasiljeva & Smirnov, 1969 (Chydoridae, Anomopoda, Branchiopoda) is redescribed, based on the type and on new material. A. labrosa is a remarkable species that shows many traits which are unique or rarely observed in Alona, and are a mix of primitive and advanced characters. A close relationship between A. labrosa and the groundwater species A. phreatica Dumont, 1983 was revealed. It is probable that these two species, possible together with some other, will need to be allocated into a subgenus or even genus in the future. However, more detailed investigations of other marginal species of Alona are necessary for understanding the position of A. labrosa among Aloninae.

A new species of Pseudochydorus Fryer, 1968 (Cladocera: Anomopoda: Chydoridae) from South-East Asia

A new species of genus Pseudochydorus Fryer, 1968 (Cladocera: Anomopoda: Chydoridae) is described from South-East Asia. P. bopingi sp. nov. differs from Palearctic P. globosus (Baird, 1843) by a smaller size, well-developed flattened flange along the posterior margin of the valves, shorter rostrum, smaller ocellus, and details of antenna and thoracic limb II morphology. P. bopingi sp. nov. is known from South China and South Vietnam, but probably has a wider distribution. Our results suggest that populations from outside of Palearctic may belong to separate species as well.

A revision of the genus Leberis Smirnov, 1989 (Cladocera: Chydoridae) in the Old World and Australia

A comparison between populations of the diaphanus-group of Leberis Smirnov, 1989 from Australia and India confirmed that Australian L. diaphanus (King, 1853) and Indian L. punctatus (Daday, 1898) are separate species. Morphology of parthenogenetic females of L. punctatus is redescribed for the first time. Some fine details of morphology are re-examined in other species of Leberis, taxonomically significant features and their variability are studied. In the Old World L. punctatus could be confused with L. diaphanus, but the former differs from the latter mainly in the details of thoracic limbs I and IV. Both species have relatively broad distribution ranges: L. punctatus inhabits South Asia, Africa and penetrates Southeast Asia, L. diaphanus is a widespread taxon in the water bodies of Australia, Southeast Asia and South China. Diversity of the genus in the Old World is underestimated yet, and further investigations are desirable.

Cladocera biodiversity in La Tembladera Lake (Ecuador): a palaeolimnological approach

Cladocera (Crustacea: Branchiopoda) biodiversity was examined in sediment assemblages in La Tembladera Lake, on the southern coast of Ecuador. We found remains from 14 Cladocera taxa belonging to three families: Sididae, Daphnidae and Chydoridae. One taxon is planktonic ( Ceriodaphnia spp.) and 13 taxa are littoral ( Sarsilatona serricauda , Chydorus sp., Dunhevenia sp., Leberis sp., Alona sp., Magnospina dentifera , Kurzia sp., Acroperus tupinamba , Camptocercus sp., Oxyurella longicaudis , Leydigiopsis sp., Euryalona sp. and Notoalona cf. sculpta ). Descriptions and pictures of the remains were included in this article to help palaeolimnologists identify tropical cladoceran remains in the sediment. These results enlarge the crustacean biodiversity data for dry tropical forests in South America and help to constrain our understanding of their geographical distribution. Further studies should focus on capturing living cladocerans to make identifications at the species level and to help interpret the sedimentary signal using ecological data.

Cladocera of Hainan Island, China

The cladoceran fauna of Hainan Island (China) was investigated. Samples were collected in January 2013 and in April 2014 from over hundred water bodies, including large and small reservoirs, ponds and pools, rivers, streams, and paddy fields. There are no large natural lakes on the island. We found 53 species of Cladocera: 9 species of Sididae; 5 Daphniidae; 2 Moinidae; 2 Macrothricidae; 2 Ilyocryptidae; 3 Bosminidae; and 30 Chydoridae. Planktonic communities were dominated by Diaphanosoma dubium Manuilova, 1964, D. excisum Sars, 1885, D. sarsi Richard, 1894, Moina micrura Kurz, 1874 and Bosminopsis deitersi (Richard, 1895). Six Chydoridae species are first records for China. The fauna consists mostly of Oriental and Pantropical species, but, also includes non-tropical Palaearctic species and East Asian endemics. For these species, Hainan Island is the southernmost record. The number of species is rather small, compared to adjacent areas. This may reflect a low intensity of sampling, but more likely a lack of natural lakes. Communities in reservoirs suffer from water level fluctuations, and the absence of permanent macrophyte stands, a preferred habitat of littoral cladocera.