Acyrtus rubiginosus

Common Name

Red Clingfish

Year Described

Poey, 1868


Dorsal Fin: 9-10
Anal Fin: 8-9
Pectoral Fin: 24-27
Caudal Fin: 5+5 principal and 4-6 upper and lower procurrent rays
Vertebrae: 11+12 precaudal, 16-17 caudal

Head large and flattened with a laterally compressed posterior end. Eyes large and dorsally placed. Mouth terminal and small. Interorbital less than eye diameter. Snout short. Anterior nostril with cirri. Posterior nostril adjacent. Gill membranes connected but free from isthmus. Branchiostegal membrane contiguous with operculum. Subopercular spine poorly developed with a weak groove. Ventral sucking disk well developed (length 27-32%, width 22-31% SL). Disk U-shaped and covered in numerous papillae (7-8 rows). Region C has no paired papillae posteriorly. Papillae on anterior edge of region B large and irregular. Dorsal and anal fins located far back on body and are across from each other. Caudal fin truncate. Fleshy pad on lower pectoral base absent.


Body and head whitish to translucent with several red bands on body. These bands can be very well defined or diffuse, especially on the head. The band behind the pectoral base, under the anterior dorsal, and tail base are usually the most obvious. Body bands often with white center lines bisecting band. Three red bands radiate from bottom half of eye with bright white bands in between them. Two white bands across head between eyes. Head often covered in dense small blue spots. Eye bright red to pale (with or without bands depending on the darkness/age of the specimen) and with a white ring around the pupil. Rear of body usually with small red spots in the pale interspaces. Fins with small red spots along finrays. Anterior dorsal fin and base of tail red. Paired fins reddish.


A tiny species: usually less than 36mm SL.


Lives in very shallow water (<5m) in rubble zones, patch reefs, and intertidal pools in limestone rock.


Widespread in the Caribbean Sea on continental and insular coasts (Bahamas to Tobago).


Conway, K.W., Baldwin, C., & M.D. White. 2014. Cryptic diversity and venom glands in western Atlantic clingfishes of the genus Acyrtus (Teleostei: Gobiesocidae). PloS One, 9(5), e97664.

Sampaio, C.L., Nunes, J.D.A.C., & L.F. Mendes. 2004. Acyrtus pauciradiatus, a new species of clingfish (Teleostei: Gobiesocidae) from Fernando de Noronha Archipelago, Pernambuco state, Northeastern Brazil. Neotropical Ichthyology, 2, 206-208.