Synalpheus ul (Ríos & Duffy, 2007)

Material examined: Pernambuco — Goiana: 1 M, 1 OV , Praia de Catuama, 20.i.2023, 7°39′18.6′′S 34°49′28.1′′W, 1.5 m depth, in sponge, MOUFPE 21811 ; Cabo de Santo Agostinho: 7 M, 2 OV , 1 F, Baía de Suape, 15.viii.2022, 8°21′54′′S 34°56′50′′W, 3.5 m depth, in sponge, MOUFPE 21784; 1 M, 1 OV, Baía de Suape, 16.viii.2019, 8°21′54′′S 34°56′50′′W, 3.5 m depth, associated with E. dendroides, MOUFPE 21511; 1 M, 1 OV , same data as MOUFPE 21511, in unindentified sponge, MOUFPE 21512; 4 M, 1 OV, same data as MOUFPE 21511, MOUFPE 21517; 1 M, 1 OV, same data as MOUFPE 21511, MOUFPE 21514; 5 M, 1 OV, same data as MOUFPE 21511, MOUFPE 21518; 2 M, 1 OV, same data as MOUFPE 21511, in unindentifed sponge, MOUFPE 21520; 1 M, 1 OV, same data as MOUFPE 21511, in unindentified sponge, MOUFPE 21516; 3 M, same data as MOUFPE 21511, in unindentified sponge, MOUFPE 21515; 3 M, 1 OV, same data as MOUFPE 21511, in unindentified sponge, MOUFPE 21519; 3 M, 1 OV, Baía de Suape, 26.x.2018, 8°21′54′′S 34°56′50′′W, 3.5 m depth, associated with E. dendroides, MOUFPE 21593; 6 M, same data as MOUFPE 21593, MOUFPE 21588 ; 1 OV, same data as MOUFPE 21593, MOUFPE 21582; 1 M, 1 OV, same data as MOUFPE 21593, MOUFPE 21529; 1 M, 1 OV, same data as MOUFPE 21593, MOUFPE 21586; 1 M, 1 OV, same data as MOUFPE 21593, MOUFPE 21591; 1 M, same data as MOUFPE 21593, MOUFPE 21527; 1 OV, same data as MOUFPE 21593, MOUFPE 21531; 2 OV, same data as MOUFPE 21593, MOUFPE 21524; 1 M, 1 OV, same data as MOUFPE 21593, MOUFPE 21592; 1 M, same data as MOUFPE 21593, MOUFPE 21533; 1 M, 1 OV, same data as MOUFPE 21593, MOUFPE 21604; 3 M, 3 OV, same data as MOUFPE 21593, in unindentided sponge, MOUFPE 21862; 1 M, 2 OV, Baía de Suape, 21.iii.2019, 8°21′54′′S 34°56′50′′W, 3.5 m depth, associated with E. dendroides, MOUFPE 21578; 2 M, 1 OV , same data as MOUFPE 21578, MOUFPE 21580; 1 M, 1 OV, same data as MOUFPE 21578, MOUFPE 21525; 2 M, 2 OV, same data as MOUFPE 21578, MOUFPE 21534; 1 M, 1 OV, same data as MOUFPE 21578, MOUFPE 21532; 1 M, 1 OV, same data as MOUFPE 21578, MOUFPE 21590; 1 M, 2 F, Praia do Paraíso, 23.ix.2022, 8°21′54′′S 34°56′50′′W, associated with E. dendroides, DZ / UFRGS 7048 ; Tamandaré: 1 M, 1 OV , Praia de Carneiros, 06.vi.2019, 8°41′32′′S 35°4′25′′W, 2.0 m depth, in sponge, MOUFPE 21598 ; 27 M, 13 OV, 2 F, Praia de Carneiros, 22.iii.2019, 8°41′32′′S 35°4′25′′W, 3.5 m depth, associated with E. dendroides, MOUFPE 21599 (genetic voucher, genbank access PV273118); 2 M, 1 OV , Praia de Carneiros, 20.vii.2019, 8°41′32′′S 35°4′25′′W, 3.5 m depth, associated with E. dendroides, MOUFPE 21606; 2 M, 1 OV , same data as MOUFPE 21606, MOUFPE 21607; 1 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21605; 1 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21608; 1 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21609; 1 F, same data as MOUFPE 21606, MOUFPE 21616; 1 OV, same data as MOUFPE 21606, MOUFPE 21624; 2 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21623; 1 M, 1 F, same data as MOUFPE 21606, MOUFPE 21625; 1 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21613; 1 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21614; 2 M, same data as MOUFPE 21606, MOUFPE 21615; 2 M, same data as MOUFPE 21606, MOUFPE 21617; 1 OV, same data as MOUFPE 21606, MOUFPE 21810; 3 M, 1 OV, same data as MOUFPE 21606, MOUFPE 21618 .

Description: Ríos & Duffy (2007), Almeida et al. (2012), and Anker et al. (2012).

Distribution: Belize, Panama, Jamaica, Dominican Republic, Saint Martin, Barbados, Curaçao, and Brazil (Pernambuco, Alagoas, Sergipe and Bahia) (Hultgren et al. 2011; Almeida et al. 2012; Anker & Pachelle 2014; Barros-Alves et al. 2015).

Ecology: In shallow reefs; associated with rubble and seagrass banks with abundance of sponges, and substrates covered by bryozoans; obligate symbiont of sponges (e.g., Hymeniacidon sp., Hyattella sp., Lissodendoryx sp., Xestospongia sp.); in heterosexual pairs (see Remarks below); shallow waters to 52 m (Ríos & Duffy, 2007; Anker et al. 2012; Anker & Pachelle 2014).

Remarks: Anker et al. (2012) stated that S. ul forms heterosexual pairs; however, groups ranging from 2–6 to 42 individuals, with varying proportions of males and females, were observed in the same host sponge (see Discussion section for details). Some organisms were parasitized in the gill chamber by bopyrid isopods (1 OV, MOUFPE 21518; 1 M, MOUFPE 21525; 1 OV, MOUFPE 21862).

Morphological variations were observed in our material. In some specimens (1 M, MOUFPE 21529; 6 M, MOUFPE 21599), the mesial spiniform setae on the posterior margin of the telson were slightly longer and broader than the lateral, as previously reported by Hultgren et al. (2010).

Herein, we provide the first 16S gene sequences for the species in the southwestern Atlantic. Our sequences are identical to sequences of specimens collected in the Caribbean Sea (Barbados and Panama) (Fig. 19) (detailed in Discussion section).