Meristic studies of the Gulf of California species of Merluccius,with a description of a new species

Two distinct species of hake are found in the Gulf of California, and in view of the commercial importance of at least one of these, a detailed taxonomical study was carried out. A new species of hake is described from the northern Gulf of California: Merluccius hernandezi. A new population of Merluccius angustimanus was located off the coast of the state of Sinaloa, Mexico. A provisional examination of specimens from this population shows that it differs in important characteristics from the specimens described by Garman (1899) from Panama.

Merluccius hernandezi and M. angustimanus from Sinoloa are immediately separable by the shape of their caudal fin and the lengths of their pectoral fins: in M. hernandezi the caudal fin has a central lobe and in larger specimens it is truncate, while in M. angustimanus it is emarginate; the pectoral fin projects well beyond the anus in M. hernandezi but not in M. angustimanus.

A meristic index was devised which can be used successfully to distinguish between the two species in the field: only 4·13% of specimens studied would have been wrongly identified using this index.