First record of Euchirograpsus americanus A . Milne-Edwards , 1880 ( Crustacea : Decapoda : Plagusiidae ) from northeastern Brazil

Th e crab Euchirograpsus americanus A. Milne-Edwards, 1880 (Plagusiidae) has so far only been recorded in Brazil in the state of Rio Grande do Sul. Here we report its fi rst occurrence from northeastern Brazil, from the Potiguar Basin in the state of Rio Grande do Norte. key woRdS Continental shelf, geographic distribution, Potiguar basin, Grapsoidea. Th e family Plagusiidae is represented by marine crabs with a subcircular to quadrate carapace, and the anterolateral margins with one to several teeth behind the exorbital angle (Melo, 1996; Ng et al., 2008). Th is family currently is comprised of fi ve genera: Plagusia Latreille, 1804, Euchirograpsus H. Milne Edwards, 1853, Miersiograpsus Türkay, 1978, Davusia Guinot, 2007, and Guinusia Schubart & Cuesta, 2010, with a total of 20 species (Ng et al., 2008). SHoRt commUnication This article is part of the tribute offered by the Brazilian Crustacean Society in memoriam of Michael Türkay for his outstanding contribution to Carcinology Nauplius, 24: e2016023 CORRESPONDING AUTHOR Flavio de Almeida Alves-Júnior bio avio@hotmail.com SUBMITTED 5 September 2016 ACCEPTED 5 November 2016 PUBLISHED 28 November 2016 Guest Editor Célio Magalhães DOI 10.1590/2358-2936e2016023

Th e family Plagusiidae is represented by marine crabs with a subcircular to quadrate carapace, and the anterolateral margins with one to several teeth behind the exorbital angle (Melo, 1996;Ng et al., 2008).Th is family currently is comprised of fi ve genera: Plagusia Latreille, 1804, Euchirograpsus H. Milne Edwards, 1853, Miersiograpsus Türkay, 1978, Davusia Guinot, 2007, and Guinusia Schubart & Cuesta, 2010, with a total of 20 species (Ng et al., 2008).The genus Euchirograpsus currently comprises ten described species, largely occurring on bottoms of sand, sandy mud, mud, rock with gorgonians and sponges, from 10 to 510 m depth (Manning and Holthuis, 1981;Melo, 2010;Wilson and Pohle, 2016).Only two species have been recorded in Brazilian waters: Euchirograpsus antillensis Türkay, 1975 distributed in the states of Maranhão, São Paulo and Rio Grande do Sul and Euchirograpsus americanus A. Milne-Edwards, 1880, so far recorded only from the state of Rio Grande do Sul (Melo, 1996;1998;2010).In this study we report for the first time the occurrence of E. americanus from northeastern Brazil.

SHoRt commUnication
The Potiguar Basin is situated in the extreme northeast of Brazil, between the states of Ceará (CE) and Rio Grande do Norte (RN) (Alves-Júnior et al., 2016).The samples were collected on board of the R/V "Seward Johnson" in 2011, as part of the project "Avaliação da biota bentônica e planctônica da Bacia Potiguar e Ceará (Bpot)" sponsored by "Petróleo Brasileiro S/A (Petrobrás)".
The samples were obtained by bottom trawls (otter trawl semi-balloon type with 50 mm mesh size and 18 m of mouth opening), conducted on the continental slope between 150-2068 m of depth.All material collected was preserved in 70% ethanol.In the laboratory, the specimen was sorted and identified to species level by observing the diagnostic morphological characters according to A. Milne-Edwards (1880), Türkay (1975) and Melo (1996).The specimen was measured with a digital caliper (0.01 mm) at: carapace length (CL), carapace width (CW) and abdomen width (AW).The specimen has been deposited in the Carcinological Collection of the "Museu de Oceanografia Prof. Petrônio Alves Coelho (MOUFPE)", of the "Universidade Federal de Pernambuco" in Recife, Brazil.In the geographic distribution section, the new record is listed in bold.Alvarez, 1968;Türkay, 1975;Melo, 1996;1998;Wilson and Pohle, 2016).

SyStematicS
Remarks.The single specimen is in agreement with the original description of A. Milne-Edwards (1880), as well as subsequent descriptions by A. Milne-Edwards and Bouvier (1894), Rathbun (1918), Türkay (1975) and Melo (1996).The species was represented by only one specimen among 30 sampling stations in the Potiguar Basin.
The only two species of genus Euchirograpsus found in Brazil (E.americanus and E. antillensis) are very similar to each other; however, E. americanus has three to four subdistal teeth on the inferior margin of the merus of the second pair of pereopods, being at least one of them larger, versus all short and of the same length in E. antillensis; moreover, the lateral spines of the carapace are slightly longer in E. antillensis than in E. americanus (Türkay, 1975, fig. 16) (Fig. 1C).
Some specimens of Euchirograpsus were identified as E. americanus from Galapagos Islands and Madagascar by Crosnier and Thomassin (1975), but, after further review, the individuals were described as two new species, Euchirograpsus pacificus and Euchirograpsus madagascariensis by Türkay (1975;1978).Until the revision by Türkay (1975), E. americanus was also wrongly recorded in the eastern Atlantic

Record of Euchirograpsus americanus, northeastern Brazil
This article is part of the tribute offered by the Brazilian Crustacean Society in memoriam of Michael Türkay for his outstanding contribution to Carcinology

Order Decapoda Latreille, 1802 Infraorder Brachyura Latreille, 1802 Family Plagusiidae Dana, 1851 Genus Euchirograpsus H. Milne Edwards, 1853 Euchirograpsus americanus A. Milne-Edwards
Geographic distribution.Western Atlantic-Canada (Bay of Fundy), USA (towards the Carolina's in Toms/ Meys Canyon and Baltimore Canyon, Massachusetts in Canyon at the edge of Georges Bank, New Jersey, Louisiana, Florida), Gulf of Mexico, Dry Tortugas, Cuba, Caribbean Sea, Antilles, West Indies, Barbados, Colombia, Venezuela and Brazil (Potiguar Basin -Rio Grande do Norte and Rio Grande do Sul) (Zariquiey