COMPOSITION, IDENTIFICATION AND TEMPORAL PATTERNS OF FISH LARVAE AT THE NAF RIVER ESTUARY, TEKNAF, BANGLADESH

Abstract

To determine the marine larval family and their distribution, composition, and spawning season, the current study was carried out in the Naf River Estuary, Teknaf, from March 2020 to February 2021, over a 12-month period. A number of 1681 individual were identified under Clupeidae, Engraulidae, Ambassidae, Blenniidae, Sillaginidae, Gobiidae and Carangidae family; among which Clupeidae was the dominant family with 757 individuals; which was followed by Engraulidae (553) and Ambassidae (322). The highest larval abundance at Naf Estuary was recorded to be 704/1000 m³ in August whereas the lowest abundance was 5/1000 m³ in March. The month of August had the highest number of larvae, whereas the month of April had the most families (04). The highest Shannon-Wiener index was observed in the post-monsoon season while family richness and evenness were highest in winter. Identified families use the Naf estuary as a nursing ground. The spawning season was identified based on the larval frequency. Clupeidae and Ambassidae larvae have been recorded in seven distinct months, indicating that their spawning season was summer, pre-monsoon, monsoon and post-monsoon. The Naf river estuary is most productive in the summer (April to August), according to the identification of four (04) families as early summer spawners. This research would be useful for future researchers based on the Cox's Bazar coast and the Naf River Estuary.