Synalpheus androsi Coutière, 1909

Anker, Arthur & Pachelle, Paulo P. G., 2014, Taxonomic notes on some Brazilian species of Synalpheus Spence Bate, 1888, with new records and description of a new species (Decapoda, Alpheidae), Zootaxa 3815 (2), pp. 215-232 : 216-218

Synalpheus androsi Coutière, 1909

( Fig. 1 )

Synalpheus androsi Coutière 1909: 82 , fig. 50; Chace 1972: 86; Dardeau 1984: 18; Coelho et al. 2006: 52; Macdonald et al. 2006: 169; Macdonald et al. 2009: 7, fig. 2, pl. 1C; Hultgren & Duffy 2011: 357, fig. 2 (in cladogram); Almeida et al. 2012: 28; Anker et al. 2012: 81 (table), 88 (key).

Zuzalpheus androsi — Ríos & Duffy 2007: 9 , pl. 1.

Material examined. 1 male (cl 3.4 mm), Brazil, off Espírito Santo, REVIZEE—Comissão Central: 2, R/V Astro Garoupa, station 21C, 20º42’21’’S 35º27’25’’W, depth: 55 m, 08.XI.1997 [ MZUSP 31138]; 1 male (cl 3.0 mm), same collection data as for previous specimen [ MZUSP 31139]; 1 male (cl 3.0 mm, major P1 missing), 1 male (cl 2.6 mm, most pereiopods detached), 1 female (cl 2.6 mm, most pereiopods detached), same collection data as for previous specimens [ MZUSP 31140]; 1 specimen (not sexed), Brazil, Bahia, off Salvador, Saldanha Leste I Expedition, station AS 1981, 13°40’S 38°48’W, depth: 49 m, sand and gravel, leg. N. Oc. Almirante Saldanha, det. E. Silva, 23.IX.1968 [ MOUFPE 9212] (material examined by J. Fidelis).

Description. See Coutière (1909) for original description and illustrations and Ríos & Duffy (2007, under Zuzalpheus androsi ) for diagnosis; comparative illustrations of the Brazilian material are provided in Fig. 1 .

Distribution. Western Atlantic: Bahamas (Andros Island), Belize (Carrie Bow Cay), Jamaica, Barbados ( Coutière 1909; Dardeau 1984; Ríos & Duffy 2007; Macdonald et al. 2009; Hultgren et al. 2011), Brazil (off Bahia and Espírito Santo: Vitória-Trindade seamounts) (Coelho et al. 2006; present study).

Ecology. In Belize, Synalpheus androsi inhabits large demosponges, Pseudoceratina crassa (Hyatt) and Hyattella intestinalis (Lamarck) , at a depth range of 14–15 m ( Ríos & Duffy 2007). The present material was dredged from much deeper water (49–55 m) and the collection records give no indication on association with sponges.

Remarks. The present material represents the first confirmed and illustrated record of Synalpheus androsi in Brazilian waters, closely matching the description and illustrations in Coutière (1909). Almeida et al. (2012) pointed out that the first record of S. androsi from Brazil by Coelho et al. (2006) required confirmation. This record was merely a listing of S. androsi in a species table, without a specific locality other than Bahia, and without illustrations. The corresponding material was deposited in the collections of Museu de Oceanografia Petronio Alves Coelho in Recife (MOUFPE) under the accession number DOCEAN-9212. At our request, Jesser Fidelis examined Coelho’s material, a single dry specimen that had to be rehydrated, and confirmed it as S. androsi (see material examined for collection details).

Synalpheus androsi is unique within the Synalpheus gambarelloides ( Nardo, 1847) species group in having a deep excavation on the ventral surface of the third and fourth pereiopods, forming very pronounced lateral flanges. On the third pereiopod, this excavation extends from the distal half of the merus to the proximal half of the propodus, gradually flattening towards the dactylus, and is the deepest on the merus and the opposed surface of the carpus ( Fig. 1 K, L). Thus the third pereiopods can be folded with the lateral and mesial flanges of the carpus fitting into and mesial to, respectively, the excavation of the merus ( Fig. 1 K). This probably helps the shrimp to squat more effectively and gain additional space in the most narrow sponge canals.

Noteworthy and in direct relationship to its morphological distinctiveness, S. androsi appears to have no close relatives in the western Atlantic Ocean, forming a moderately supported clade with the eastern Atlantic S. gambarelloides (Hultgren & Duffy 2011) .

Figures

FIGURE 1. Synalpheus androsi Coutière, 1909, male (cl 3.4 mm) from off Espírito Santo, Brazil [MZUSP 31138]: A—frontal region, dorsal; B—same, lateral; C—abdomen, lateral; D—telson, dorsal; E—third maxilliped, lateral; F—major (right) cheliped, lateral; G—same, chela, mesial; H—minor (left) cheliped, lateral; I—same, carpus and chela, mesial; J—second pereiopod, lateral; K—third pereiopod, lateral; L—same, distal merus, carpus and proximal propodus, ventrolateral; M—same, distal propodus and dactylus, lateral; N—uropod, dorsal.