American Sole

Achirus mucuri is distinguished from all its congeners, except A. novoae, bypossessing a connection on both the blind and ocular sides between the branchiostegal membrane and the isthmus, with the connection being slightly stronger on the blind side (vs. complete absence of connections between branchiostegal membranes and isthmus). Additionally, the species is distinguished from its congeners by having a light-brown body color, with regularly-scattered, minute, darkbrown blotches that are sometimes concentrated to form larger spots. Five specimens differed from the typical light-brown body color in having a brownish-gray background, and one specimen showed brownish-white body pigmentation. The new species differs from A. novoae by the presence of a large, ramified labial fimbriae (vs. simple, non-ramified, minute labial fimbriae in A. novoae) and by the shape of the infraorbital canal (extending around ventral margin of fixed eye) (vs. infraorbital canal thatstops dorsal to fixed eye in A. novoae (Ref. 80995).

The American sole (Achirus mucuri) is a species of sole in the family Achiridae. It was described by Robson Tamar da Costa Ramos, Telton Pedro Anselmo Ramos and Paulo Roberto Duarte Lopes in 2009. It inhabits the Mucuri River in Brazil, from which its species epithet is derived. It reaches a maximum standard length of 9 cm (3.5 in).