Acyrtops amplicirrus

Common Name

Flarenostril Clingfish

Year Described

Briggs, 1955


Dorsal Fin: 5-7
Anal Fin: 5-7
Pectoral Fin: 21-23
Caudal Fin: 8-10 principle rays

Body relatively elongate with a laterally compressed abdomen and a dorso-ventrally flattened head. Snout from above bluntly rounded. Head widest at opercle. Mouth subterminal with folds and lappets along lip margin. Teeth in 2-5 rows in lower jaw. Eye fairly small (about 53-63% of interorbital distance). Anterior nostril with a small dermal flap. Posterior nostril simple and behind anterior margin of orbit. Opercle with a small dermal flap. Caudal peduncle relatively deep. Dorsal and anal fins opposite each other. Anus closer to anal fin than it is to pelvic disk. Pectoral fin broad and fan-shaped with lower rays shortened. Pelvic disk small with papillae anteriorly and sparse papillae posteriorly. Lateral line pores restricted to head.


Body and head bright green overall peppered with tiny black melanophores. There are scattered larger gray to pale blue spots on the upper body that become denser on the head. Several dark lines radiate from the eye. Belly paler green. Fins translucent with green anterior edges.


A small species: adult males to 1.9cm SL.


Found in shallow seagrass beds (<3m) where it lives attached to the seagrass blades.


Appears to be restricted the the southeastern Caribbean in the Lesser Antilles. Described from St. Croix, VI. Limits of range not known.


Briggs, J.C. 1969. The clingfishes (Gobiesocidae) of Panama. Copeia, 774-778.

Gould, W.R. 1965. The biology and morphology of Acyrtops beryllinus, the emerald clingfish. Bulletin of Marine Science, 15 (1), 165-188.

Johnson, R.K. & D.W. Greenfield. 1983. Clingfishes (Gobiesocidae) from Belize and Honduras, central America, with a redescription of Gobiesox barbatulus Starks. Northeast Gulf Science, 6 (1), 33-49.

Smith-Vaniz, W.F. & H.L. Jelks. 2014. Marine and inland fishes of St. Croix, US Virgin Islands: an annotated checklist. Zootaxa, 3803(1), 1-120.

Other Notes

Rimicola brevis is considered a synonym of Acyrtops from coastal Panama.

The two described Caribbean Acyrtops species are very similar in appearance the the extent and limits of their ranges is not known. It is not even certain if they are simply one species or a complex of several species. Gould (1965) concluded the two species cannot be distinguished but Johnson & Greenfield (1983) kept them separate. As meristics overlap, it seems like a combination of eye size, interorbital distance, and head length can separate them. More research needs to be done on this genus. The population in the Lesser Antilles is defined as A. amplicirrus at this time.