DNA barcoding supports sexual dimorphism in two Labrid species; Cheilinus lunulatus and Halichoeres hortulanus (Family Labridae) in Red Sea, Egypt

Abstract

Labrids (wrasses) are characterized by great phenotypic differentiation during development. Most wrasses are brightly colored, often with complex patterns. They usually display extreme color variation between sexes to the point of considering them different species. The purpose of this paper is to re-examine intra-specific sexual dimorphism in two common wrasses; Cheilinus lunulatus and Halichoeres hortulanus. We used morphometric and DNA barcoding analyses to determine whether morphological differences are due to gender or species differences. Results showed that most of body related measurements in males and females were sexually dimorphic. However, no distinct difference was observed in cytochrome oxidase subunit I (COI) sequence between the examined individuals of C. lunilatus and those of H. hortulanus, thus confirming that the phenotypic differences are due to sexual dimorphism and not species differences. Keywords: Sexual dimorphism, DNA barcoding, Labrid fish, Cheilinus lunulatus, Halichoeres hortulanus