DNA barcoding and morphological characterization of marine stingrays (genus Fontitrygon) from the African Gulf of Guinea

Abstract

The coastal marine stingrays (genus Fontitrygon) include two endemic and highly threatened species (Fontitrygon margaritella and Fontitrygon margarita) from the African Gulf of Guinea. However, the lack of robust diagnostic features due to similar external features hinders species identification, thus limiting species‐specific conservation efforts. The present study aims to examine the morphological characteristics and apply a DNA barcoding tool through amplifying mitochondrial cytochrome C oxidase subunit I (mtCOI) to accurately identify F. margaritella and F. margarita from coastal waters in Nigeria, Cameroon, Côte d'Ivoire, Guinea Bissau and Senegal. Morphological evaluation revealed differences in colour pattern, eye shade, mouth shape and pectoral radial count between F. margarita and F. margaritella. We generated 25 mtCOI barcode sequences that included F. margaritella (n = 22) and F. margarita (n = 3). Our query search in the National Center for Biotechnology Information (NCBI) GenBank and Barcode of Life Data system (BOLD) showed a sequence match of our newly collected F. margaritella with other F. margaritella in the global databases, while mtCOI sequences of F. margarita were new to the NCBI GenBank and BOLD databases. The phylogenetic clustering analyses based on the maximum‐likelihood tree grouped morphospecies into highly supported monophyletic units. Our study demonstrates the potential of combined molecular and morphological approaches in the identification of coastal marine stingrays from the Gulf of Guinea. Our study is helpful in future scientific studies and in forming future conservation plans.