Investigation of larval fish biodiversity in Yumurtalık bight (Adana) with DNA barcoding

Fish are highly fecund organisms. They reproduce by depositing a large number of eggs, ranging in size from 0.5 mm to 2 mm, into the water column or various substrates based on species characteristics. Iskenderun Bay is known as one of the important fishing areas in the Eastern Mediterranean. In Iskenderun Bay, Yumurtalık Bight is an important spawning ground due to the surrounding lagoons, serving as both a breeding and nursery habitat. In this study monthly ichthyoplankton samplings were carried out from December 2020 to December 2021 at 13 stations and the collected larvae were identified using morphological and molecular methods down to the lowest taxonomic level. Based on measurements during sampling, the in-bay temperature ranged from 10.7°C to 30.4°C throughout the year. A total of 1473 larvae and 52839 eggs were collected during the sampling process. Morphological and molecular analyses indicated that these eggs and larvae belonged to 80 taxa from 34 different families within 17 distinct orders. When evaluated economically, 11% of the collected specimens represented species with very high economic value, while 43% of species were with high commercial importance. Among the species utilizing the bay for spawning and nursery, 71% were indigenous and 29% were non-indigenous species. Furthermore, the study revealed that Pomatomus saltatrix (Bluefish) and Umbrina cirrosa (Shi drum), listed in the IUCN Red List, use the region as a breeding and feeding area.