Comparison of morphomeristical variations of Mediterranean and Red Sea populations of the Suez Canal migrant Sargocentron rubrum

Abstract

Nine morphomeristical characters of squirrelfish, Sargocentron rubrum (Forsskal 1775) were compared between Mediterranean and Red Sea populations to examine changes caused by different environments. The significantly lower number of lateral line scales and vertebrae in the Mediterranean fishes is attributed to the higher temperature during the spawning season. The significant difference of the proportion of suborbital spinulation and the shape of the anterior tip of the nasal bone is inferred to be due to a founder effect. No significant difference was found in the relationship between eye diameter and preopercular spine length and standard length, nor in the number of dorsal and anal rays and nostril spinulation.