Achelous gibbesii ( Stimpson, 1859 )

Rodrigues, Iana Barbosa & Serejo, Irene Azevedo Cardoso and Cristiana Silveira, 2017, Catalogue and illustrated key of Achelous De Haan, 1833 and Portunus Weber, 1795 (Brachyura: Portunidae: Portuninae) species occurring in Brazilian waters, Nauplius (e 2017005) 25, pp. 1-12 : 2-3

Achelous gibbesii ( Stimpson, 1859)

( Fig. 2A )

Material examined. Brazil, Maranhão, Tutóia , 1 female (cw 36; cl 22), DOUFPE 7120 .

Diagnosis. Carapace approximately twice as wide as long, not protuberant, with small spherical granules, pubescent, and with naked, transverse ridges, two of which arise from posterior anterolateral tooth and arch toward gastric region. Frontal region with eight teeth; median teeth and submedian teeth more advanced than lateral frontal teeth 1 and 2, these two pairs subequal in size. Posterior anterolateral tooth, slender, sharp, curved slightly forward and about as long as space occupied by three preceding teeth. Chelipeds long, slender (especially in males); merus with four to seven spines in front and one spine behind at distal end, carpus with large internal and smaller external spine. Merus of swimming leg with row of spinules on posterodistal edge (modified from Williams, 1984).

Measurements. Carapace: male, cl 37, cw 76; ovigerous female, cl 35, cw 66 ( Williams, 1984). Male, cl 29, cw 56.4, width between anterior bases of lateral spines 46.4 ( Rathbun, 1930).

Color. Brownish red, transverse ridges on carapace, spines and margins of chelipeds carmine red; front side of legs brilliantly iridescent by lantern light, iridescence evident to some extent in preserved specimens ( Williams, 1984).

Geographic distribution. Western Atlantic: USA (Massachusetts to Florida), Gulf of Mexico ( USA, Florida to Mexico, Cancun), Venezuela, Guyana and Brazil (Maranhão) ( Coelho and Ramos-Porto, 1992; Almeida & Coelho, 2008); Caraguatatuba, SP (GBIF, 2016).

Type localities. St. Augustine and the Keys , Florida

( USA).

Habitat. From surface to 90 m. On mud, sand and broken shells bottom. Usually in deeper parts of bays and estuaries ( Melo, 1996).

Figures

Figure 2. A,Achelous gibbesii, DOUFPE 7120; B,Achelous ordwayi, MNRJ 16244; C, Achelous rufiremus, MNRJ 301.Scale bars:2cm.