Arcos nudus

Common Name

Padded Clingfish

Year Described

Linnaeus, 1758


Dorsal Fin: 7-8
Anal Fin: 6-7
Pectoral Fin: 23-25
Caudal Fin: 5+5 principal and 4-6 upper and lower procurrent rays
Vertebrae: 11 precaudal, 14-15 caudal

Head large and flattened with a laterally compressed posterior end. Fleshy lobes under chin but not on rest of head or body. Eyes large and dorsally placed. Mouth terminal and small. Top lip broad at front. A prominent patch of incisors at front of upper jaw. Interorbital less than eye diameter. Snout short. Anterior nostril with forked flap. Posterior nostril adjacent. Gill membranes connected but free from isthmus. Ventral sucking disk large and well developed. Disk U-shaped and covered in numerous small papillae (broad, dense bands on front and rear and central region with 2 patches). No cluster of papillae on anterolateral area of Region C. Dorsal and anal fins located far back on body and are across from each other. Caudal fin truncate. Fleshy pad on lower pectoral base present.


Body whitish with 5 faint body bands: two between pectoral and dorsal fin, one under dorsal fin, one on caudal peduncle, and one on the base of the tail. Head with faint dark blotches and bands radiating from eye. Body and head covered with dense greenish to orange spots which give the body a white reticulated appearance. Spots are darker and larger in area of banding. Eyes are pale mottled with brown bands and a red ring around the pupil. Brown spots on median finrays. Dark specimens can have 3-4 brown bands on the tail. Paired fins clear.


Maximum size to 81mm SL.


Shallow reefs and surge zones. Usually <10m.


Widespread in the Caribbean Sea on continental and insular coasts.


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.

Other Notes

Arcos macrophthalmus is a synonym.