Nauplius 21(1): 53-63, 2013 53 A new species of Cymadusa Savigny, 1816 (Crustacea: Amphipoda: Ampithoidae) from northeastern Brazil Luiz F. Andrade and André R. Senna Centro Universitário de Volta Redonda (UniFOA), Curso de Ciências Biológicas. Av. Paulo Erlei Alves Abrantes, 1.325, Prédio 1, Três Poços, CEP 27240-560, Volta Redonda, RJ, Brasil. E-mails: (LFA) [email protected]; (ARS) [email protected] ABSTRACT - A new species of the amphipod family Ampithoidae Stebbing, 1899 is described from the northeastern Brazilian waters. The new described taxon is grouped in the genus Cymadusa Savigny, 1816, since it presents all the diagnostic characteristics of the genus. The examined material was collected by scuba diving in the Rocas Atoll, off Rio Grande do Norte state coast, Camamu Bay and Todos os Santos Bay, Bahia state. The new species described here is close to C. filosa Savigny, 1816, type species of the genus, by presenting anterior margin of gnathopod 1 poorly setose, male gnathopod 2 densely setose, with palmar corner not defined by a spine and dactylus subequal in length to palm, being considered part of the C. filosa complex. Among the species of this complex, the one which most resembles to the new taxon is C. imbroglio Rabindranath, 1972, which is distinguished by the absence of both the trapezoid process in the palm and spine at the palmar corner in the gnathopod 2. This is the second species of the genus Cymadusa recorded from Brazilian waters. Key words: Amphipods, Camamu Bay, Rocas Atoll, Taxonomy,Todos os Santos Bay INTRODUCTION Brazil, grouped in three genera: Ampithoe The Amphipoda belong to the Superorder Leach, 1814, Cymadusa Savigny, 1816 and Peracarida, a crustacean group with direct Sunampithoe Bate, 1857 (Wakabara and Serejo, development, incubating the eggs in a 1998; Serejo and Licínio, 2002). It shows the marsupium ventral to the thorax formed paucity of taxonomic studies about the group from thin plates called oostegites. Amphipoda in Brazil. includes, currently, about 7.000 species The family Ampithoidae is characterized grouped into four suborders: Senticaudata, by presenting the following characters: Gammaridea, Hyperiidea and Ingolfiellidea, corophioidean diagnostic characters; outer lobe according to Lowry and Myers (2013). of lower lip usually with notch; inner ramus The amphipods from the family of uropod 3 as short as the outer ramus, wide Ampithoidae Stebbing, 1899 are among and apically setose, or outer ramus of uropod the most abundant associated to the phytal 3 with 1-2 recurved thick setae diverging from substrates (Nelson 1979; Edgar 1983a, b; the ramus axis (Barnard and Karaman, 1991). Duffy, 1990). Despite this, there are only six As concerns the genus Cymadusa, only C. ampithoid species recorded until now from filosa Savigny, 1816 (type species of the genus) c Published by Brazilian Crustacean Society, Ribeirão Preto, Brazil - July 2013 54 Andrade and Senna: New amphipod Cymadusa from Brazil is recorded from Brazilian waters. Another (03º52’S / 033º48’W). The collections were species, Grubia sardenta Oliveira, 1953, made from October 2000 to November described with material from Guanabara Bay, 2001, during the project Oceanic Islands 1 m depth, was synonymized to C. filosa by Diversity – Rocas Atoll, coordinated by the Peart (2004), despite some morphological Departamento de Invertebrados, Museu differences between the two species. The type Nacional, Universidade Federal do Rio de series of this material is currently lost and the description and illustrations made by Oliveira Janeiro. This atoll is located at the peak of a (1953) are not well detailed. Thus, it is still seamount, about 150 km west of the Fernando necessary to analyze materials of collections de Noronha archipelago and 267 km northeast from this species type locality, to confirm or of the Rio Grande do Norte State. The algae not the validity of the species described by samples were anesthetized with 5-10% Oliveira. ethanol and washed in a 0.5mm mesh sieve. The species of the genus Cymadusa, Some paratypes were also collected using can be easily recognized among the other the same methodology at the Camamu Bay Ampithoidae, by presenting uropod 1 with (13º56’S / 39º06’W) and Todos os Santos long and sharp distoventral spike (spur), on the tip of the peduncle, between the basis Bay (12°46’22”S / 38°33’32”W), both in the of rami. According to Peart (2007), species Bahia State coast. All the examined material of Cymadusa tend to be bigger, brighter for this study is preserved in 70% ethanol. and more colorful than other amphipods. For the taxonomic study, the appendages and Genus Cymadusa has accessory flagellum on mouthparts of the dissected specimens were antenna 1, as the easer way to distinguish this mounted on glycerol gel slides and drawn genus from all others. However, despite the under an optical microscope with camera abundance and size of individuals, the genus lucida, Motic BA-310. Illustrations were taxonomy remains ambiguous, because of digitalized in CorelDraw X5, using a Wacon inadequate definitions and descriptions. Peart Intuos 4 tablet. All the material is deposited at (2004) defined a species complex around C. the Crustacea Collection of the Departamento filosa, including six species with strongly setose de Zoologia, Universidade Federal do Rio antennae and gnathopods. However, some of de Janeiro (DZUFRJ), and the Crustacea these species do not present these appendages Collection of Museu Nacional (MNRJ). too much setose, as illustrated by the author The setae classification used on this work herself. follows the one proposed by Watling (1989) In this paper, we describe a new species and the gnathopods 2 palm nomenclature was of Cymadusa, the second one recorded from based on Poore and Lowry (1997). Brazilian waters, and the first one known from List of abbreviations used in figures: the Rocas Atoll, as for the northeastern Brazilian Hd: Head; LL: Lower lip; UL: Upper lip; coast. This species is part of the C. filosa complex Mp: Maxilliped; Mx1-2: Maxillae 1-2; Md: since it presents antennae and posterior margin of merus, carpus and propodus, and palm of Mandible; Gn1-2: Gnathopods 1-2; P3-7: gnathopods 1 and 2, besides anterior margin Pereopods 3-7; Ep1-3: Epimeral plates 1-3; of propodus of gnathopod 2 well setose. U1-3: Uropods 1-3; T: Telson; Af: Accessory flagellum; m: male; f: female. MATERIAL AND METHODS The examined material was collected RESULTS on sublittoral algae by scuba diving at the Order Amphipoda Latreille, 1816 northeastern Brazilian coast. The type material Suborder Senticaudata Lowry and Myers, 2013 is from the Rocas Atoll Biological Reserve Family Ampithoidae Stebbing, 1899 Nauplius 21(1): 53-63, 2013 55 Genus Cymadusa Savigny, 1816 gel slides, dissected and drawn, Camamu Bay, Genus diagnosis: Antenna 1 longer Bahia State, Brazil, 13º56’S / 39º06’W, A.O. than antenna 2, accessory flagellum with 1-2 Almeida coll., 24 April 2004, subtidal, from articles. Mandibular palp 3-articulate. Lower washed algae, DZUFRJ 4938; 5 females, lip outer lobe notched. Gnathopod 1 smaller in ethanol 70%, Camamu Bay, Bahia State, or subequal to gnathopod 2. Gnathopod 1 Brazil, 13º56’S / 39º06’W, A.O. Almeida coll., palm of propodus acute. Pereopods 3 and 4 24 March 2005, subtidal, from washed algae, with basis and merus narrow. Uropod 1 with DZUFRJ 4939; 11 females, 3 males, in ethanol distoventral spur long and acute. Uropod 3 70%, Todos os Santos Bay, Bahia State, Brazil, rami short and broad. Uropod 3 outer ramus 12°46’22”S / 38°33’32”W, O. Falcão coll., 22 with two recurved robust setae. Modified from May 1997, subtidal, from washed algae, MNRJ Peart (2004). 15770; 3 females, in ethanol 70%, Rocas Atoll, Rio Grande do Norte State, Brazil, F.B. Type species: Cymadusa filosaSavigny, 1816 Pitombo, R. Barroso coll., 25 December 2000, subtidal, from washed algae, MNRJ 23407; Genus composition: Genus is composed 5 females, in ethanol 70%, Rocas Atoll, Rio by 36 species: Cymadusa alyxis Hughes & Grande do Norte State, Brazil, F.B. Pitombo, Lowry, 2009; C. aungtonyae Peart, 2002; C. R. Barroso coll., 21 December 2000, subtidal, brevidactyla (Chevreux, 1907); C. cavimana from washed algae, MNRJ 23408; 2 females, (Sivaprakasam, 1970); C. chalongana Peart, in ethanol 70%, Camamu Bay, Bahia State, 2002; C. chuawe Peart, 2007; C. compta Brazil, 13º56’S / 39º06’W, A.O. Almeida coll., (Smith, 1873); C. crassicornis (Costa, 1853); C. 24 April 2004, subtidal, from washed algae, elegantis Peart, 2007; C. filosa Savigny, 1816; DZUFRJ 4940; 1 male, dissected and drawn, C. grossimana Ledoyer, 1984; C. hawaiensis 7.1 mm length, Camamu Bay, Bahia State, (Schellenberg, 1938); C. heronensis Peart, Brazil, 13º56’S / 39º06’W, A.O. Almeida coll., 2007; C. hoeyae Hughes & Lowry, 2009; C. 24 April 2004, subtidal, from washed algae, imbroglio Rabindranath, 1972; C. jigurru DZUFRJ 4941; 1 female, in ethanol 70%, Peart, 2007; C. khbanardi Hughes & Lowry, Camamu Bay, Bahia State, Brazil, 13º56’S / 2009; C. ledoyeri Peart, 2004; C. lunata Myers, 39º06’W, A.O. Almeida coll., 24 April 2004, 1985; C. mariabyrneae Hughes & Lowry, subtidal, from washed algae, DZUFRJ 4942; 2009; C. microphthalma (Chevreux, 1901); C. 1 male, in ethanol 70%, Rocas Atoll, Rio munnu Poore & Lowry, 1997; C. oceanica J.L. Grande do Norte State, Brazil, F.B. Pitombo, Barnard, 1955; C. panwa Peart, 2002; C. pathyi R. Barroso coll., 25 December 2005, subtidal, Asari, 1998; C. peartae sp. nov.; C. pemptos from washed algae, DZUFRJ 4943. Peart, 2007; C. pilipes (Ledoyer, 1984); C. Etymology: This species is dedicated to setosa (Haswell, 1879); C. smilodonta Hughes Dr. Rachel Peart, for her great contribution to & Lowry, 2009; C. tattersalli Peart, 2004; C. the knowledge of the ampithoid amphipods. thagaay Peart, 2007; C. tishana Peart, 2007; Diagnosis: Antenna 1 poorly setose, with C.