First record of the genus Megamphopus Norman, 1869 (Crustacea, Amphipoda, Photidae) from Brazilian waters, with description of a new deep sea species Jesser F. Souza-Filho * ,1 and Andr R. Senna 2 1 Universidade Federal de Pernambuco, Museu de Oceanografia. Av. Arquitetura, s/n, Cidade Universitria, CEP 50740 – 550, Recife, PE, Brasil 2 Centro Universitrio de Volta Redonda/UNIFOA, Departamento de Cincias BiolÕgicas. Av. Paulo Erlei Alves Abrantes, 1325, Trs Poos, CEP 27240 – 560, Volta Redonda, RJ, Brasil Introduction The genus Megamphopus Norman, 1869 is widely dis- tributed worldwide, including the Antarctic Ocean, from shallow waters to 750 m depth (Barnard & Kara- man 1991; Ren 1991; Myers 1998). It is a member of the Gammaropsis-complex, which is a catch-all for a number of loosely related taxa (Myers 2009). Although Barnard & Karaman (1991) classified Megamphopus as a subgenus of Gammaropsis, this proposal was not fol- lowed by several other authors (Ren 1991; Myers 1998; Myers & Lowry 2003; Bakir et al. 2011). Indeed, this genus is distinguished from the other genera within the Gammaropsis-complex in having coxa 2 longer than coxae 1 and 3 – 7 in male. Nowadays, it comprises 13 species including the new species described herein. Brazil is a megadiverse country, and in fact is the richest region for many animal taxa (Mittermeier 1988; Marques & Lamas 2006). Nevertheless, the deep sea fauna from Brazil remains poorly known, especially the crustacean fauna. During the last 15 years some expe- ditions have collected deep sea samples and some new records and new taxa have been described (e.g. Silva et al. 1997; Wakabara & Serejo 1999; Tavares 1999; Viana et al. 2002; Albuquerque & Costa, 2008; Val- rio-Berardo 2008; Larsen et al. 2009; Cardoso 2011; Senna 2010). One of them was the Campos Basin Deep-Sea Environmental Project (Oceanprof ), coordi- nated by Cenpes/Petrobras, which has yielded an abun- dant collection between 700 and 900 m depth off Rio de Janeiro. Part of the taxonomic results were recently published in two books (Lavrado & Brasil, 2010a, b) and some papers (Senna & Serejo 2008; Sittrop & Serejo 2009; Senna 2009, 2010), but there are still many species waiting to be described (e.g., benthic am- phipods, isopods and tanaids). Amongst the amphipods collected in this project, we have found a new species of the genus Megamphopus, which is described in this paper. Also, a key with all species of the genus is pro- vided. # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Zoosyst. Evol. 88 (1) 2012, 71 – 77 / DOI 10.1002/zoos.201200008 Received 14 September 2011 Accepted 30 September 2011 Published 16 March 2012 Key Words Taxonomy Crustacea Corophiidea Oceanprof Campos Basin Brazil Southwestern Atlantic Abstract A new species, Megamphopus robustisetae sp. n., is described from the deep waters of Campos Basin, Rio de Janeiro, Brazil. The new species is easily distinguished from its congeners by lacking eyes and the distinct ornamentation of gnathopod 2 of both male and female. This paper raises the number of species of Megamphopus Norman, 1869 to 13. Also, the genus Megamphopus is recorded for the first time from Brazil. A key with all species of the genus is provided. * Corresponding author, e-mail: jesser_fidelis@yahoo.com.br