Caragobius Smith and Seale

Edward O. Murdy & Koichi Shibukawa, 2003, A revision of the Indo-Pacific fish genus Caragobius (Gobiidae: Amblyopinae)., Zootaxa 301, pp. 1-12 : 1-2

[[ Caragobius Smith and Seale ]]

Caragobius typhlops was described as a new genus and species by Smith and Seale (1906) from five specimens collected from the Rio Grande near Cotabato, Mindanao, Philippines. Smith and Seale’s description of Caragobius was rather unremarkable except that they mentioned their specimens possessed “a small pore above each gill-opening which opens into a cavity separate from gill-cavity”; among gobioid fishes, this character is unique to Amblyotrypauchen , Ctenotrypauchen , Trypauchen , and Trypauchenichthys [members of the Trypauchen Group of Murdy (2002) as modified from Birdsong et al. (1988)]. Smith and Seale (1906) did state that Caragobius was related to Trypauchen but differed in “squamation, teeth, eyes, etc.”.

Herre (1927) examined Smith and Seale’s specimens of Caragobius typhlops and determined that the pore above the gill cavity [shallow pouch along the dorsal edge of the operculum] was not present in any of the specimens. Herre (1927) surmised that Smith and Seale (1906) may have confused a tear in the skin with a pore. Koumans (1940) concurred with Herre's assessment and allied Caragobius with his Taenioininae (Koumans, 1931), a group comprising eight genera, but none of the Trypauchen-Group genera named above. Furthermore, Koumans stated that Caragobius was probably synonymous with Brachyamblyopus , one of the members of his Taenioininae. Subsequently, Koumans (1953) provisionally synonymized Caragobius with Brachyamblyopus .

Birdsong et al. (1988) placed Caragobius in their Trypauchen Group, an assemblage that did not include Brachyamblyopus , but did include Amblyotrypauchen , Trypauchen , and Trypauchenichthys . This group was defined by its shared possession of a pterygiophore formula (PF) of 3-1221 that is unique among gobiid fishes. Murdy and Shibukawa (2002) reported that the holotype of Amblyopus brachysoma Bleeker (1853), the type for the genus Brachyamblyopus , has a PF=3-12210 and, thus, correctly belongs in the Taenioides Group of Birdsong et al. (1988).

Among Trypauchen-Group members, all but Caragobius and Karsten possess a shallow pouch along the dorsal edge of the operculum (“blind sac-shaped depression” of Hora, 1924); the function of this pouch is not known. Murdy (2002) proposed that Caragobius is the sister group to all other Trypauchen-Group members and Karsten is the sister group to all Trypauchen-Group members that possess an opercular pouch.