Moving towards the west: Morphological and molecular documentation of the reef margin blenny Entomacrodus striatus (Teleostei: Blenniiformes) from the most western part of the Indo-Pacific Ocean

Authors

1 Ichthyology and Molecular Systematics Research Laboratory, Department of Biology, School of Science, Shiraz University, Shiraz, Iran

2 Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran

10.22092/ijfs.2024.132448

Abstract

For most marine organisms, including fish, species diversity is very high in the Indo-Pacific region, and it reflects how past and present environmental conditions shape a link between biodiversity and ecosystem function. The distribution of a taxon in the region is due to the establishment of morphological, genetic, behavioral, and physiological aspects of species. Despite extensive surveys in the Indo-Pacific region still, there are new species and new records especially in the case of small cryptic species such as blennies. The family Blenniidae including members of the genus Entomacrodus are mostly small fishes of less than 15 cm having an elongate and slender body with a worldwide distribution. Entomacrodus comprises herbivorous combtooth blennies with about 27 species, 7 of which occur in the western Indian Ocean. In this study, the presence, general morphology, otolith shape variation, osteology, distribution, and molecular phylogenetic affinity of the reef margin blenny Entomacrodus striatus have been documented/presented from the westernmost part of the Indo-Pacific region (the Jask Port, Oman Sea). The morphological and meristic characteristics of specimens were well fit with E. striatus. The vertebral column includes 10 abdominal and 23 caudal vertebrae, for a total vertebral count of 33. Corroborating the morphological results, DNA barcoding based on mitochondrial COI confirmed that the specimens collected from the Jask Port area are conspecific with E. striatus from other Indo-Pacific localities. Entomacrodus striatus from the Oman Sea and other Indo-Pacific regions show a distinct clade sister to a clade of E. epalzeocheilos, E. niuafoouensis, and E. randalli with a closest phylogenetic relationship to E. niuafoouensis (0.108 K2P genetic distance). The presence of E. striatus in the coastal area of the Oman Sea in the Jask coastal area represents the first record of this species for the westmost of the northern Indian Ocean and markedly expands its known geographical distribution range.

Keywords