A new species of Anchoviella Fowler, 1911 (Clupeiformes: Engraulidae) from the mouth of the São Francisco River (Sergipe, Alagoas, Brazil)

Anchoviella sanfranciscana, sp. n. is described for the estuary of the Sao Francisco River (States of Sergipe and Alagoas, northeastern Brazil). It is distinguished from its congeners by a combination of the following characteristics: (1) a very wide silver lateral band with above another well-defined dark brown and yellow lateral band  - its total width is 1.5 to 2 times wider than the ocular diameter; (2) the distance from the tip of the dorsal fin to the start of the anal fin is similar in size as the dorsal fin itself; and (3) the number of rakers in the lower branch of the first branchial arch is unique among its congeners, 29-35, and in this respect it is comparable only to A. cayennensis . However, A. sanfranciscana has a more robust body than A. cayennensis and is anatomically similar to that of A. lepisdostostole , from which it is distinguished by the position of the insertion of the anal fin in relation to the dorsal fin.