An updated checklist of clupeiform fishes (Teleostei: Clupeiformes) in the North-Western Indian Ocean: Taxonomy, diversity, distribution, and conservation status

Abstract

The present study lists species diversity of the order Clupeiformes in most parts of the Northwest Indian Ocean (NIO) and encompasses the marine waters of the Persian Gulf, Oman Sea, Arabian Sea, Red Sea, and the Gulf of Aden. The updated checklist enumerates 57 species, representing 21 genera and sex families. The family Dorosomatidae presents 9 genera and 21 species. Within this family, the genera Sardinella with 6 species (10.52%), Nematalosa with five species (8.77%), and Herklotsichthys with three species (5.26%) comprise ranks first, second, and third in terms of species diversity. The Tenualosagenera represent two species (3.50%), and five remaining genera including Anodontostoma, Amblygaster, Escualosa, Gudusia, and Hilsa have one species each (1.75%). In the family Engraulidae, the genera Thryssa presents 10 species (17.55%), Encrasicholina four species (7.02%), Stolephorus three species (5.26%), Coilia two species (3.50%), and Engraulis one species (1.75%). In the family, Pristigasteridae, the genera Ilisha presents five species (8.77%), Opisthopterus two species (3.50%), and Pellona presents one species each (1.75%). The family Dussumieriidae presents 2 genera and 4 species. The genera Dussumieria and Etrumeus with two species present for each genus (3.50%). The families Chirocentridae and Spratelloididae present one genus and two species, which is 1.75% for each species. During the last 10 years, only seven new species have been described from the region: Encrasicholina macrocephala, Encrasicholina intermedia, Encrasicholina gloria, Thrissina cultella, Thrissina serena, Stolephorus meteorum, and Stolephorus tamilensis. Species diversity of the Persian Gulf and the Oman, Arabian, and Red Seas is different due to substantial variations in the environmental features and oceanographic characteristics of the Persian Gulf (e.g., sea surface temperature ranges, salinity, depth, geographic position, and its geological history during the glaciation in Pleistocene. Based on the IUCN red list, most of the reported species (43 species, 75.45%) have been rated as “least concern” (LC), and the other species (13 species, 22.80%), and one species (Tenualosa toli) as “vulnerable” (VU). Further research is underway, and it is expected that other species may be present in the northwestern Indian Ocean.