Quadrimaera pieteri Krapp-Schickel & Ruffo, 2000

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 : 583-584

Quadrimaera pieteri Krapp-Schickel & Ruffo, 2000

( Fig. 15 )

Examined material: Paratypes. 2 Females ( MSNV 392 ) Lesser Antilles: St. Martin-Bridge (Type Locality), September, 25 th 1928, P. Hummelinck coll.

1 Male ( UFBA 1993 ), 4.9 mm, Caramuanas (12°57'15.6"S; 38°35'41.7"W), Bahia State, Brazil, associated with Mussismilia hispida . February 2011 .

1 Male ( UFBA 3325 ), 5.9 mm. Parque Nacional Pedra da Risca do Meio (3 o 33’ 800”S, 38 o 26’ 000” W), Ceará State, Brazil, associated with sponge Callyspongia vaginalis . July, 14 th 2004, Bezerra, L.E.A. coll.

3 Females ( UFBA 3326 ) 3.9, 3.5 and 3.5 mm. Marine State Park of Pedra da Risca do Meio (3 o 33’ 800”S, 38 o 26’ 000” W), Ceará state, Brazil, associated with sponge Angelas sp. April, 21 th 2013 .

15 juveniles ( UFBA 3327 ) 3.6 to 4.0 mm. Pirangi Beach (5°59'00.2"S; 35°06'30.1"W), RN State, Brazil, associated with Halimeda opuntia intertidal zone (0–2 m of depth). March 2010. CARNEIRO, P.B. Coll .

Description. (based on material from Northeastern Brazil) Gnathopod 1 coxa 1 with anteroventral corner acute and slightly produced, basis longer than ischium and merus together; carpus elongated with discreet anterodistal excavation, ventral margin with dense row of plumose setae; propodus subequal in length to carpus, posterior margin with 3 sets of simple setae, palm beset with minute setae; dactylar inner margin with slight sinuosity, not clear in all specimens ( Fig 15 ).

Gnathopod 2, coxa 2 subquadrate, beset with small setae; basis strong, posterior margin with 2 slender setae; carpus reduced, subtriangular; propodus enlarged, propodus palm ornamented with clear central U-shaped excavation, preceded by proximal subtriangular process and proceeded by distal subrectangular process, palm defined by an acute process strongly to weakly pronounced, preceded by U to V-shaped excavation; dactyl inner margin with weakly to strong sinuosity, visible in both specimens ( Fig 15 ).

Pereopod 5 with slender basis, posteroventral corner rounded and produced, dactyl with a bifid nail. Pereopod 7 basis with posterior margin strongly globose; propodus posterior margin with long setae. Uropod 2 peduncle slightly longer than rami; outer and inner rami similar in length. Uropod 3 peduncle shorter than rami, outer ramus longer than inner, with 2 sets of setae. Telson deeply cleft, telson lobes with 3 distal setae as long as telson length ( Fig 15 ).

Remarks. Specimens of Quadrimaera pieteri described from the northeastern Brazil, differs from the paratypes from Lesser Islands because of the posterior margin of P7 that is slightly more globose than the specimens from the type locality (this difference is not clearly observed in females), and by having U2 with peduncle longer than rami while the paratypes examined have a similar length. Considering that these characters are sexually dimorphic in many genera of Family Maeridae , including Quadrimaera , and the original description of Q. pieteri was based in an ovigerous female, we consider that the specimens here analyzed belong to this species. These specimens are also very similar to Quadrimaera prope pieteri Krapp-Schickel & Ruffo, 2000 from Rio de Janeiro, especially by the palm variations of gnathopod 2 propodus and the sets of setae of the U3 outer ramus. The genus Quadrimaera is known to present variations on Gnathopod 2 propodus palm between females, ovigerous females, juveniles, adult and hyperadult males. Moreover, Krapp et al. (1996) reported the presence of intermediate, and hybrid species, resulting from the reproduction between different species of the Pacific Quadrimaera . Thus, considering the variations founded among Brazilian and Caribbean specimens, and the wide intraspecific polymorphism of Quadrimera, it is assumed that all Brazilian specimens belong to the same species Q. pieteri .

Distribution. Lesser Antilles, Caribbean Sea (Type locality). In Brazil, Parque Nacional Pedra da Risca do Meio, Ceará State. Pirangi beach, Rio Grande do Norte State. Boipeba beach, Bahia State. Prainha beach, Arraial do Cabo, Rio de Janeiro State. The species shows a continuous distribution from the Caribbean Sea to southeastern Brazilian coast, being restricted to the Tropical Atlantic Marine Eco region proposed by Spalding et al. (2007).

Figures

FIGURE 15. Quadrimaera pieteri Krapp Schickel & Ruffo, 2000: male 4.0 mm. Marine State Park of Pedra da Risca do Meio (3 o 33’ 800”S, 38 o 26’ 000” W), Ceará state, Brazil. Scale bars: 0.5 mm (Gn1, Gn2, P5, P7); 0.3 mm (U2, U3, T).