Osteology of the sea mojarra, Diapterus auratus Ranzani (Teleostei: Gerreidae)

Abstract

In the skeleton of the sea mojarra Diapterus auratus, modifications relative to the protractible upper jaw are noticeably, such as the great length of de premaxillary ascendent processes, passing through the maxillary groove and lodging in the anterior fossa of the neurocranium. The supraoccipital crest is remarkably high, while parietal crests are discontinuous. From the 6 suborbitals, the third one bears a subocular shelf. The myodomus has a posterior opening. Two extrascapular bones are present. Ten precaudal and 13 caudal vertebrae, 3 supraneurals, 17 dorsal and 9 anal pterygiophores are counted. Comparing with other gerreid genera, a homogeneity in the number of repeated structures is recognized. The temporal region of the head is where most differences are found; however, urohyal is the more variable bone among genera. More characters similar to those of Eugerres are identified.