Relationship between shape and trophic ecology of selected species of Sparids of the Caprolace coastal lagoon (Central Tyrrhenian sea)

Abstract

The shapes of juveniles of nine species of the family Sparidae (Diplodus annularis, Diplodus puntazzo, Diplodus sargus, Diplodus vulgaris, Lithognathus mormyrus, Pagellus acarne, Sarpa salpa, Sparus aurata, Spondyliosoma cantharus), collected in the tide channel of the Caprolace Lagoon (Central Tyrrhenian Sea—Italy) were studied using geometric morphometry. These species have different ecologies. The trophic ecology of each species, reported as TROPH values, are related to shape. For the first time the relationship between shape and trophic ecology in sparids was studied in a quantitative way giving an ecomorphological meaning to the shape differences. Mean shapes of carnivorous, omnivorous and herbivorous fish were extracted, analyzed and found to be unique. Strict herbivores such as Sarpa salpa have a small mouth gap; omnivores such as the four species of the genus Diplodus have a higher body (discoidal) and a caudal peduncle shorter and higher; carnivorous species such as Lithognathus mormyrus, possess a relatively larger head region, a larger mouth gap, a longer body and a caudal peduncle longer and narrower.