Quadrimaera rocasensis Senna & Serejo, 2007

Alves, Jessika, Neves, Elizabeth & Johnsson, Rodrigo, 2018, A review of Quadrimaera Krapp-Schickel & Ruffo, 2000 (Amphipoda: Senticaudata) from Brazil, Zootaxa 4532 (4), pp. 567-593 : 585-586

Quadrimaera rocasensis Senna & Serejo, 2007

( Fig. 16 )

Examined material. 3 Males ( UFBA 3322 ) 5.0 mm, Pirangi Beach (5°59'00.2"S; 35°06'30.1"W), Rio Grande do Norte State, Brazil, associated with calcareous Halimeda opuntia , intertidal zone (0–2 m of depth). March 2010. CARNEIRO, P.B. Coll .

3 Females ( UFBA 3323 ) 3.5 mm, 3.1 mm and 3.9 mm. Pirangi Beach (5°59'00.2"S; 35°06'30.1"W), Rio Grande do Norte State, Brazil, associated with Halimeda opuntia , intertidal zone (0–2 m of depth). March 2010. CARNEIRO, P.B. Coll .

1 Female ( UFBA 3324 ) 4.0 mm. Caramuanas (12°57'15.6"S; 38°35'41.7"W), Todos-os-Santos Bay, Bahia State, Brazil. February 2011, associated with Mussismilia hispida .

Diagnosis. (Modified from Senna & Serejo, 2007) Gnathopod 1, coxa 1 with anteroventral corner rounded and anterior margin projected. Gnathopod 2 with robust and subrectangular propodus; palm transverse with one proximal and one distal U-shaped concavities on males and a distal one in females. Distal U-shaped concavity preceded by a truncated process and proceeded by an acute and pronounced process in both sexes. Dactyl inner margin with acute projection opposite to palmar concavity, and strongly pronounced in males. Telson deeply cleft, with apical lobes with bifid setae on both sexes.

Female (Sexual dimorphic characters). Gnathopod 1, coxa 1 with anteroventral corner rounded, anterior margin slightly projected; basis longer than ischium and merus together, posterior margin with 7 slender setae; carpus facially setose, with more setae than in males; propodus ovate, facially setose, propodus palm with minute setae; dactyl inner margin naked. Gnathopod 2 basis strong, anterior margin with stout setae, anteroventral corner rounded and produced, posterior margin with 2 slender setae; carpus reduced, subtriangular; propodus robust subrectangular, with setae on both margins, propodus palm setose with U-shaped concavity preceded by broad and truncate process and proceeded by acute and pronounced process that defines the palmar corner; dactyl inner margin with delicate projection. Telson deeply cleft (about 78%), 0.5 times longer than wide, lobes apically notched, with 4 slender and bifid setae.

Remarks. Quadrimaera rocasensis is now firstly reported to the Brazilian continent, being founded in Pirangi Beach, Rio Grande do Norte State and Boipeba Beach, Bahia State. In the present study, we also describe the female specimen hitherto unknown to science.

Distribution. In Brazil: Atol das Rocas, Rio Grande do Norte State (Type locality). Pirangi Beach, Rio Grande do Norte State, Boipeba beach, Bahia State.

Figures

FIGURE 16. Quadrimaera rocasensis Senna & Serejo, 2007: Female 3.9 mm. Pirangi Beach, Rio Grande do Norte State, Brazil (5°59'00.2"S; 35°06'30.1"W), UFBA 3323. Scale bars: 0.5 mm.