Morphological and molecular divergence between Crenidens crenidens (Forsskål, 1775) and C. indicus Day, 1873 (Perciformes: Sparidae) and notes on a Red Sea endemic lineage of C. crenidens

Abstract

Additional data, resulting from examination of newly collected material from the Red Sea, east coast of Africa, Arabian Gulf, Pakistan, and western coast of India, and a phylogenetic analysis of the COI barcoding region, confirms Crenidens crenidens (Forsskål) and C. indicus Day as valid species. The latter species was earlier regarded as a subspecies of C. crenidens. In addition, the analyses herein show that specimens from the Red Sea form a distinct monophyletic sub-clade within C. crenidens, characterized by low genetic divergence from specimens from the southwestern Indian Ocean. Close comparison of 34 morphological characters showed that specimens from South Africa and Mozambique differ from Red Sea specimens only in having slightly longer pelvic fins [4.6–4.9 in standard length (SL) vs. 4.8–6.1 in SL]. Examination of additional specimens of both species provided more assessment of inter- and intraspecific variation in meristic and morphometric characters. A new set of characters that help to distinguish C. indicus from C. crenidens is proposed: the former species has a deeper body and caudal peduncle; more scales between fifth dorsal-fin spine and lateral line; scales on top of head extending forward to vertical through posterior margin of pupil; longer pelvic fins; lips with tiny cirri; caudal fin blackish distally; and usually with obvious black spot at pectoral-fin axil. Crenidens indicus was previously reported from central Oman, Arabian Gulf, to Pakistan; herein its presence from the western coast of India, Gujarat and Mumbai (= Bombay), is confirmed. Descriptions of C. crenidens and C. indicus based on material examined, photographs of alive and fresh fishes and an updated key to the three known species of Crenidens are provided.