Early life history of oxudercine goby Pseudapocryptes elongatus in the Mekong Delta, Vietnam

Abstract

Pseudapocryptes elongatus is one of the oxudercine gobies, which show varying degrees of amphibious behaviour and capacities to breathe air. There is little information on the early life history of P. elongatus, particularly of their morphology and larval habitat and duration. This study focused on the life history of larval and juvenile stages of P. elongatus investigated by genetic species identification, morphological observation and otolith analyses using specimens collected in June and October 2012 from estuaries in Bac Liêu Province, southern Vietnam (09°14′N 105°43′E). Genetically identified juvenile P. elongatus were characterized by (1) a slender body form, (2) the anterior edges of both the anal and second dorsal fins located at the midpoint along the body axis, (3) scarce chromatophores over the body surface, (4) melanophores in the parietal region between the eyes, and (5) a single row of melanophores along the base of the anal fin. Mean age at recruitment to estuaries was 38.0 ± 4.1 days, and otolith Sr/Ca ratios ranged from 8.9 to 9.9 mmol mol−1, suggesting that larval migration from their spawning sites requires more than 1 month in saline environments.