The use of pigmentation and morphological characters to identify Italian mullet fry

Abstract

Mullet fry from Italian coastal waters are examined to ascertain ontogenetic changes in pigmentation, external morphology, anal-fin ray counts, and morphology of the pyloric caeca and pharyngobranchial organ. The taxonomic utility of these characters is assessed. Intraspecific and ontogenetic variation in anal-fin ray numbers do not make this a consistently reliable character for identification purposes. Pharyngobranchial morphology can assist diagnoses of larger fry or juveniles; however, pigmentation patterns are the most reliable characters for smaller fry. Pigmentation characters, which can be used in laboratory- and field-based studies, require minimal manipulation of the fish and enable rapid identification of large numbers of specimens. These techniques are valuable for aquaculturists and fish biologists requiring more information on the identification, distribution and life history of mugilids.