bs_bs_banner Zoological Journal of the Linnean Society, 2014, 170, 34–85. With 33 figures On the phylogeny of Ischyroceridae (Amphipoda, Senticaudata, Corophiida), with the description of a new genus and eight new species from deep-sea Brazilian waters JESSER F. SOUZA-FILHO1* and CRISTIANA S. SEREJO2 1Departamento de Oceanografia, Museu de Oceanografia Prof. Petrônio Alves Coelho. Laboratório de Carcinologia. Cidade Universitária, Rua da Arquitetura, Universidade Federal de Pernambuco, S/N, CEP 50670-901, Recife, Pernambuco, Brazil 2Departamento de Invertebrados. Quinta da Boa Vista, São Cristóvão. Museu Nacional/Universidade Federal do Rio de Janeiro. CEP 20940-040 Rio de Janeiro, Brazil Received 29 May 2013; revised 9 October 2013; accepted for publication 9 October 2013 The family Ischyroceridae is analysed herein by cladistic methods based on morphological characters, using both PAUP 4.0b and TNT. The data matrix of 41 characters × 32 terminal taxa was constructed using DELTA. Based on the results, we comment on the phylogenetic relationships of certain genera and their synapomorphic characters, also discussing the phylogenetic position of Myersius gen. nov., which appeared as the sister group of Bathyphotis.In addition, Pseudischyrocerus crenatipes is removed to Bathyphotis, for which a new diagnosis is provided. A taxonomic study with the Ischyroceridae collected on the continental slope (depth, 700–2000 m) in the Campos Basin (20.5–24°S, 40–41°W) was also performed. Samples were collected in November–December 2002 and July–August 2003 using a box core device. As a result, a new genus and eight new species are described: Bonnierella campensis sp. nov., Bonnierella laurensi sp. nov., Myersius denticaudatus gen. et sp. nov., Notopoma lowryi sp. nov., Notopoma teresae sp. nov., Pseudericthonius bousfieldi sp. nov., Pseudericthonius concavus sp. nov., and Pseudischyrocerus caecus sp. nov. The genus Bonnierella is recorded for the first time from Brazilian waters, and the subspecies Bonnierella linearis linearis and Bonnierella linearis californica are elevated to species rank. Keys to the genera of Ischyroceridae used in the cladistic analysis and the world species of Notopoma are given. © 2014 The Linnean Society of London, Zoological Journal of the Linnean Society, 2014, 170, 34–85. doi: 10.1111/zoj.12099 ADDITIONAL KEYWORDS: Campos Basin – cladistic analysis – Corophiidea – deep sea – Ischyroceridae – new species. INTRODUCTION Podoceridae, all of which were well defined except for Corophiidae. In the same work, Barnard synonymized The taxonomic and phylogenetic relationships among the families Photidae, Aoridae, and Isaeidae with some groups of Corophioidea are controversial, and Corophiidae, but recognized no subfamilies. Other have been much discussed, including the position authors have proposed a more restricted concept of the of this superfamily within the suborder Gammari- family Corophiidae. Bousfield (1978) recognized the dea. J.L. Barnard (1973) erected the superfamily superfamily Corophioidea including nine families, Corophioidea including the families Ampithoi- among which Aoridae, Corophiidae, Photidae, and dae, Cheluridae, Corophiidae, Ischyroceridae, and Isaeidae were considered distinct families. Later on, Myers (1981) erected the family Neomegamphopidae, and retained a separate status for Aoridae and *Corresponding author. E-mail: jesser_fi[email protected] Corophiidae, whereas Photidae and Isaeidae were 34 © 2014 The Linnean Society of London, Zoological Journal of the Linnean Society, 2014, 170, 34–85 PHYLOGENY OF ISCHYROCERIDAE 35 merged with Isaeidae. Just (1983) erected the sub- The first Brazilian deep-sea amphipod, Parandania family Siphonoecetinae within Corophiidae (sensu boecki, was recorded by Stebbing (1888; as Andania Myers, 1981). Despite these proposals, J.L. Barnard boecki), and was collected by the ‘Challenger Expedi- & Karaman (1991) followed J.L. Barnard’s (1973) tion – 1873’ at a depth of 1234 m off the state of classification and submerged Ischyroceridae and Pernambuco. More than a century later, new deep-sea Neomegamphopidae within Corophiidae, but main- amphipod records off the Brazilian coast began to be tained the subfamily Siphonoecetinae. Nevertheless, reported. Fifteen studies have recorded a total of 35 Bousfield & Hoover (1997) continued giving separate amphipod species from off the Brazilian coast in waters recognition to Aoridae, Isaeidae, and Ischyroceridae below 200 m (Table 1). Despite these efforts, the Bra- within the superfamily Corophioidea, and considered zilian deep-sea amphipod fauna is still little known, the family Corophiidae to have two subfamilies, and many more species await description. Corophiinae and Siphonoecetinae. In recent decades, deep-water drilling exploration Currently, the family Ischyroceridae comprises 254 activities off the Brazilian coast intensified with the species distributed in 40 genera, with a worldwide discovery of giant oil reserves, such as the Albacora, distribution. This family is mainly characterized by Marlin, and Barracuda banks in the Campos Basin. the uropod 3 with the peduncle broad proximally and Consequently, in order to maintain sustainable deep- narrow distally, and its rami with tiny apical setae water exploration, the Petrobras Research Center or and the outer ramus with recurved apical spines; Cenpes/Petrobras (Petróleo do Brasil SA) initiated these spines are lost in siphonoecetids (Myers & the Campos Basin Deep Sea Environmental Project Lowry, 2003). Studies dealing with the evolution of (OCEANPROF). The main objective of this project the Ischyroceridae include that of Lowry & Berents was to characterize the oceanic region of the Campos (1996), who presented a cladistic analysis for the Basin according to the physical, chemical, and bio- Ericthonius group, which included the Cerapus clade, logical properties of the water and the bottom Ericthonius, Pseudericthonius, Pseudischyrocerus, between the depths of 700 and 2000 m (Lavrado and the Siphonocetid clade. Myers & Lowry (2003) et al., 2010). As a result of this project, two books proposed a new classification for the corophioideans were published in which 144 crustaceans were based on a morphological cladistic analysis, where listed (Serejo et al., 2010). Several taxonomic studies the suborder Corophiidea was erected. This suborder with Decapoda, Isopoda, and Tanaidacea from the comprised two infraorders: the Corophiida, earlier OCEANPROF have been published (e.g. Cardoso & placed within the suborder Gammaridea, and the Serejo, 2007; Albuquerque & Costa, 2008; Larsen, Caprellida, previously treated as a separate suborder. Silva & Coelho, 2009). This classification supported the previous hypothesis Among the amphipods collected by the where the Caprellida share a common ancestor with OCEANPROF project, the corophiideans were one of podocerids (Laubitz, 1979). Myers & Lowry (2003) the most important groups. The family Ischyroceridae also used feeding strategies to separate these groups, Stebbing, 1899 was represented by five genera where Corophiida were considered as derived from and eight species, distributed in two subfamilies: bottom-feeding detritivores, whereas members of the Bonnierellinae Myers & Lowry, 2003 and Ischy- Caprellida were derived from ancestors that fed on rocerinae Stebbing, 1899. Currently, 11 ischyrocerids material suspended in the water column. The work are known from Brazilian waters (Wakabara & of Myers & Lowry (2003) clarified the relationship Serejo, 1998; Valério-Berardo, 2001; Valério-Berardo, among most families of Corophioidea, and provided a Souza & Rodrigues, 2008), but the present study restricted diagnosis of most of the families discussed raised this number to 19. Taking this material into above. For example, the Ericthonius group was account, we performed a cladistic analysis based on found to be monophyletic, as observed by Lowry & morphological characters, to better understand the Berents (1996), although it appeared as a phylogenetic relationships among certain genera of Siphonoecetine within the Ischyroceridae. Also, the family Ischyroceridae, including the position of Photidae and Isaeidae were found to be separate Myersius gen. nov. described herein. Based on this families. The relationships among genera of these analysis, some minor taxonomic changes within the families were not discussed, however. Recently, Lowry family are also proposed. & Myers (2013) erected the suborder Senticaudata, defined as a monophyletic clade that shares robust setae on the apices of uropods 1 and 2. The MATERIAL AND METHODS Senticaudata included 95 families that were previ- ously assigned to the suborder Gammaridea, and all PHYLOGENETIC ANALYSIS members of the suborder Corophiidea, which is now In order to classify the material observed from the considered as the infraorder Corophiida. Campos Basin, we decided to run a cladistic analysis © 2014 The Linnean Society of London, Zoological Journal of the Linnean Society, 2014, 170, 34–85 36 Table 1. List of deep-sea species of the order Amphipoda recorded in Brazilian waters J. F. SOUZA-FILHO AND C. S. SEREJO Species Locality and depth Reference Amathillopsis atlantica Chevreux, 1908 23°54′S, 42°10′W, 830 m Wakabara & Serejo (1999) Ampelisca anae Valério-Berardo, 2008 22°27′31.62″S, 40°09′23.19″W, 750 m Valério-Berardo (2008) Ampelisca campensis Valério-Berardo, 2008 22°41′10.8″S, 40°2′20.3″W, 1650 m Valério-Berardo (2008) Ampelisca minuta Valério-Berardo, 2008 22°31′12.47″S, 40°15′11.08″W, 750 m Valério-Berardo