Acyrtus artius

Common Name

Papillate Clingfish

Year Described

Briggs, 1955

Identification

Dorsal Fin: 9
Anal Fin: 7-8
Pectoral Fin: 24-25
Caudal Fin: 5+5 principal and 4-6 upper and lower procurrent rays
Vertebrae: 11+12 precaudal, 14-15 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 not contiguous with operculum (with a deep pocket between them). Subopercular spine well developed with a strong ventral groove and a patch of modified tissue adjacent. Ventral sucking disk well developed (29-36% SL). Disk U-shaped and covered in numerous papillae. Region C with two separated patches of papillae on the anterolateral margin. 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.

Color

Head reddish, red-brown, purplish, or brown covered with tiny blue spots with dark outlines. Eye bright red with darker blotches, a thin yellow ring around pupil, a thin blue ring around outer edge, and a dark red outer ring. Body posterior to pectoral fin pale to whitish with one partial and 4 complete equally spaced bands that are usually greenish in color. The bars are finely speckled with black. The pale interspaces have numerous moderate red-brown spots that are larger than the spots on head. These spots continue forward onto top of head. Faint darker bands often cross head and run from eyes to side of head. Median fins pale with red-brown spots on finrays like the adjacent body. Paired fins clear to pale pink.

Size

A tiny species: usually less than 33mm SL.

Habitat

Coral reefs in spur/groove regions, walls, and amongst corals. Usually found deeper than 8m but less than 20m.

Range

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

References

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.

Other Notes

Closely related to Acyrtus lanthanum but differs in coloration, DNA, habitat, a venomous subopercular spine, and other smaller morphological differences in the sucking disk.