Synalpheus tenuispina Coutière, 1909
Material examined: Rio Grande do Norte—São Pedro e São Paulo Archipelago: 1 F, 30 m depth, MOUFPE 13565; Pernambuco—Ilha de Itamaracá: 1 M, 1 F, Ilha de Itamaracá, St. 01, MOUFPE 8897.
Description: Anker & Pachelle (2014).
Distribution: Brazil (São Pedro e São Paulo Archipelago, Rio Grande do Norte, Pernambuco, Rio de Janeiro, São Paulo, and Santa Catarina) (Anker & Pachelle 2014; this study).
Ecology: Dwelling in pier growth or in crevices of polychaete reefs, on Schizoporella sp. bryozoan colonies; in heterosexual pairs; shallow waters to 45 m (Anker & Pachelle 2014; Almeida et al. 2018b).
Remarks: Synalpheus tenuispina is endemic to the Brazilian coast. Caribbean records (e.g., Abele 1976; Martínez-Iglesias et al. 1993, 1996) have been reassigned to Synalpheus cf. africanus (Anker & Pachelle 2014) . This study extends the northern known range of the species.