Three new species of chydorid cladocerans of subfamily Aloninae (Branchipoda: Anomopoda: Chydoridae) from Brazil

Abstract

Three new species of Aloninae cladocera from Central and South Brazil are described. Two of them, Acroperus tupinamba sp. n. and Alona yara sp. n., were previously recorded from the area as European taxa Acroperus harpae (Baird, 1834) and Alona quadrangularis (O.F. Müller, 1776), respectively. Acroperus tupinamba differs from the other species of Acroperus in smaller size, long posterior setae of the valves, shorter and wider postabdomen, short setules near the base of postabdominal claw, long apical spines of antenna, and peculiar morphology of limb IV exopodite. Alona yara differs from A. quadrangularis and A. kolweizii Van Damme & Dumont, 2008 in the number of ventral setules on ventral face of limb I, from A. boliviana Sinev et Coronel, 2006 in the shape of the body and postabdomen, narrow labral keel, and absence of projections on epipodites IV–V. The third new species, Celsinotum candango sp.n. differs from all other species of the genus in proportions of postabdomen. It differs from Australian species (C. hypsophilum Frey, 1991, C parooensis Frey, 1991, and C. platamoides Frey, 1991) in a less developed dorsal keel, lateral head pores located close to midline, longer spine on basal segment of antennal exopodite, and in the presence of extremely large projections on exopodites IV–V. Celsinotum candango differs from Brazilian C. laticaudatum Smirnov & Santos-Silva, 1995 in a shorter spine on basal segment of antenna exopodite, in the shape of postabdomen and in morphology of postabdominal denticles. At present, Aloninae fauna of Brazil includes 35 species, and true diversity is undoubtedly higher, with more new species to be expected in the country.