The genus Eurycercus Baird, 1843 (Cladocera: Eurycercidae) in the Neotropics Author Bekker, Eugeniya I. Author Kotov, Alexey A. Author Elmoor-Loureiro, Lourdes M. A. text Journal of Natural History 2010 2010-10-12 44 41 - 42 2481 2508 http://dx.doi.org/10.1080/00222933.2010.488752 journal article 10.1080/00222933.2010.488752 1464-5262 5210553 Eurycercus (Eurycercus) cf. lamellatus (O. F. Müller, 1776) ( Figure 1 ) Material studied One juvenile female from lower reaches of Rio Nhamundá , Central Amazonia , Pará , Brazil , AAK 2003-030 . Short description of single juvenile female In lateral view body subrectangular ( Figure 1A ). Dorsal margin interrupted by a relatively shallow depression behind major head pore. In anterior view, body moderately compressed laterally, median dorsal keel well developed, although not sharp ( Figure 1B ). Head with relatively long rostrum. Compound eye relatively small, ocellus was not found, but the pigment could have been dissolved by irregularities in the preservation technique. A single major “head pore” as a ringed, suboval field of special cuticle; a minute, elongated ovoid lateral pore located at either side of major pore, closer to it ( Figure 1C ). Labrum with a medium-sized median keel, terminating in a broadly rounded apex. Postabdomen with subparallel dorsal and ventral margins. Distal anal embayment shallow. Armature of the preanal margin as a series of 101 preanal teeth in the examined specimen; teeth in middle of preanal margin with sharp tips. Spines at base of preclaw portion short, predominantly single ( Figure 1D ). Postabdominal claw robust, first (distalmost) basal spine long, second (basalmost) spine short. Antenna I relatively short, protruding greatly beyond tip of rostrum and reaching labral apex. Antennular sensory seta arising approximately in antenna I middle. Limbs not studied. Intestine has a single loop. Length 0.82 mm . Figure 1. Eurycercus cf. lamellatus , juvenile female from lower reaches of Rio Nhamundá, Central Amazonia, Pará, Brazil. (A) Lateral view; (B) anterior view; (C) dorsal head pores; (D) postabdominal claw. Scale bars: 0.1 mm. Distribution This is a common Palaearctic taxon; our finding of a single specimen in a single locality is the first adequate record of E. lamellatus (or its closest congener) in Brazil . See Discussion.