Distribution, abundance, and species composition of fish larvae and juveniles of Gobiidae in the Cimaja estuary, Palabuhanratu, Indonesia

Abstract

Cimaja estuary has been well known as a fishing ground for fish larvae and juveniles of amphidromous fishes. The local people call this group of fish impun and collect them frequently for consumption. However, no information about fish diversity and recruitment of amphidromous goby in the Cimaja estuary is known. Therefore, this study aims to reveal species composition, recruitment pattern, and estimation of the abundance of fish larval and juvenile amphidromous goby in the Cimaja estuary day and night. Sampling was performed monthly during the new moon period from December 2020 to February 2021. Fish specimens were identified to the lowest taxon level through a morphological approach. A total of 23,331 larvae and juveniles of Gobiidae were collected, and most of them were Sicyopterus spp. The juvenile stage (11.9-21.8 mm BL) comprised 95.6% of the catches, postflexion larvae (6.9-11.8 mm BL) contributed 3.5% to the total yield and 0.9% of the total capture consisting of flexion larvae (3.9-6.8 mm BL). Gobiid fishes are preferred to recruit and migrate into the Cimaja river during the day than at night time (p < 0.05), and their movement to the upstream are synchronized with the tidal cycle.