Accepted by R. Dalgleish: 31 Jan. 2007; published: 2 Apr. 2007 1 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2007 · Magnolia Press Zootaxa 1437: 1–28 (2007) www.mapress.com/ zootaxa/ Three new species of Remaneicaris Jakobi, 1972 (Copepoda, Harpacticoida, Parastenocarididae) from the Ribeirão do Ouro River, Minas Gerais, Brazil, with some remarks on the groundpattern of the Parastenocarididae PAULO HENRIQUE C. CORGOSINHO 1, 4 , PEDRO MARTÍNEZ ARBIZU 2 & EDINALDO NELSON DOS SANTOS-SILVA 3 1 Plankton Laboratory, CPBA/ INPA, Av. André Araújo, 2936 Petrópolis, CP 478, 69011-970, Manaus-AM, Brazil. E-mail: pcorgo@yahoo.com.br 2 Pedro Martínez Arbizu, DZMB – Forschungsinstitut Senckenberg, Südstrand 44, 26382 Wilhelmshaven, Germany. E-mail: pmartinez@senckenberg.de 3 Edinaldo Nelson dos Santos-Silva, Plankton Laboratory, CPBA/ INPA, Av. André Araújo, 2936 Petrópolis, CP 478, 69011-970, Manaus-AM, Brazil. E-mail: nelson@inpa.gov.br 4 Corresponding author Abstract Three new species of the parastenocaridid genus Remaneicaris Jakobi, 1972 were discovered in interstitial near-shore waters of the small river Ribeião do Ouro (a tributary of the Paraopeba river, in the São Francisco hydrographic basin). Remaneicaris tridactyla n. sp., R. paratridactyla n. sp. and R. juliae n. sp. are described in detail. The presence of a 1- segmented endopod on the male leg 3, previously reported for some Remaneicaris species, is confirmed here, and the phylogenetic relevance of this structure is discussed. These new species differ from each other by the shape of the leg 3 exopod and endopod, shape of leg 4 endopod, ornamentation of the telson and previous urosomites, and by the number of sensilla and dorsal pores. Some remarks on the groundpattern of the Parastenocarididae are given. Key words: hyporheos, Neotropis, groundpattern Introduction The family Parastenocarididae Chappuis, 1940 is a monophyletic group within Harpacticoida, being charac- terised and easily distinguished by the sexual dimorphism present in the third pair of legs. As an apomorphy, the males have these legs modified into a grasping organ (Martínez Arbizu & Moura 1994) that allows them to grasp the female during copulation (Glatzel 1991, 1996). In addition to the dimorphic third leg, the males present other modifications, mainly in the endopod of the fourth leg and, sometimes, in the first, second, fifth legs and the furca (Schminke 1991). These modifications constitute important characters used to distinguish species and supra-specific taxa. The family currently contains 241 species and subspecies, but our knowledge of the phylogenetic rela- tionships within the family is fragmentary. The monophyly of many genera proposed by Jakobi (1972) is still to be assessed. In South America, parastenocaridids encompass 66 known species, 33 of them reported from Brazil. These species belong to nine valid (see ICZN 1999 article 13) genera, viz. Parastenocaris Kessler, 1913; Remaneicaris Jakobi, 1972; Brasilibathynellocaris Jakobi, 1972; Forficatocaris Jakobi, 1969; Pararemaneicaris Jakobi, 1972; Siolicaris Jakobi, 1972; Paraforficatocaris Jakobi, 1972; Potamocaris Dus- sart, 1979 and Murunducaris Reid, 1994.