The lesser African threadfin (Galeoides decadactylus) is a species of marine ray-finned fish, a threadfin from the family Polynemidae which is found in the eastern Atlantic Ocean off the western coast of Africa. The lesser African threadfin has a rather compress, moderately elongated body with has a depth which is around one thirds of the standard length. The mouth has an inferior position and is overhung by the blunt snout. The jaws extend past the eye. It has two dorsal fins which are widely separated, the first dorsal fin has 8 weak spines and the second has a single spine and 13 or 14 soft rays while the anal fin has 3 spines and 11 or 12 soft rays. The second dorsal fin and anal fin have bases which are approximately equal in length. The pectoral fins are positioned low on the body, this fin has 9 or 10 detached threadlike lower rays. It has a count scales in the lateral line of 45–46. This species is a dull silvery colour, with a brownish to green tint in the back fading to whitish on the breast and belly. There is a large, round, dusky blotch directly below the first dorsal fin which sits beneath the lateral line at level of first dorsal fin, this blotch is similar in size to the eye. The lesser African threadfin can attain a total length of 50 centimetres (20 in) but 30 centimetres (12 in) is more normal. The lesser African threadfin is found in the eastern Atlantic Ocean from Morocco south as far as Angola. It is also found around the Canary Islands and Cape Verde Islands and has been recorded off Namibia and in the Mediterranean Sea off Algeria.
