Synalpheus biunguiculatus (Stimpson, 1860)
Synalpheus biunguiculatus is a Indo-West and eastern Pacific snapping shrimp first described from Hawaii by Stimpson (1860); a neotype was established by Banner (1953). This species has been found under rocks and stones, in coral, on oyster racks, and under sponges, typically in the shallow subtidal.
Synalpheus biunguiculatus was first described as Alpheus biunguiculatus by Stimpson (1860) based on material from Hawaii; Banner (1953) established a neotype and a thorough redescription. Neotype locality: Hawaii (Banner 1953), types stored at the National Museum of Natural History, Smithsonian Institution (USNM). Neotype: USNM 93453.
This species has been found under rocks and stones, in coral, on oyster racks, and under sponges, typically in shallow subtidal (Stimpson 1860, Hendrickx et al. 1983, Wicksten 1983).
Maximum body size is 5.7 mm (Abele 1975). Closely related to Synalpheus albatrossi, but can be separated by a number of characters, including the rostral base (broader than base of orbital teeth in S. albatrossi, narrower than base in S. biunguiculatus) and the basicerite (without upper spine in S. biunguiculatus, with acute upper spine in S. albatrossi); see Banner (1953) for more details. Body color translucent sky blue with dark red chromatophores on body, major chela with orange spot at propodal-dactylar junction; females with brown eggs (specimens from Mexico, Wicksten 1983).
not Alpheus biunguiculatus (de Man 1887; Bate 1888 = S. coutierei; Coutiere 1898 = Synalpheus pachymeris); not Synalpheus biunguiculatus (Coutiere 1898, 1899, 1900, 1905, 1921; Borradaile 1899, Nobili 1901, 1906, Pearson 1905, Tattersall 1921; Balss 1927, Ramadan 1936, Coutiere 1899).
Indo-West Pacific: Hawaii, Clipperton, Gulf of California, W. Mexico, Panama, Malpelo Island, Colombia, Galapagos (Banner 1953, Abele 1975, Hendrickx et al. 1983).