New insights into early stages of Lateolabrax maculatus (McClelland, 1844) in a tropical estuary of northern Vietnam

Abstract

Lateolabrax maculatus (McClelland, 1844) (Lateolabracidae) has commercial significance for fisheries and recreational fishing in northern Vietnam, which is likely the southernmost limit of its distribution. Despite its importance as a food source, little is known on characteristics of its early life history. So we provide new insights on early-stage larvae of L. maculatus based on monthly collections from September 2014 to August 2015 in the center of the current of the Kalong estuary which drains into the Gulf of Tonkin in northern Vietnam. Larvae only occurred in January in the stages of preflexion with yolk sac to postflexion, ranging from 3.4 to 9.2 mm in body length. Early stage larvae of L. maculatus were characterized by having a relatively elongate body, thick and long gut, anus located at the middle of the body, a myomere count of 35–37, and with scattered and light pigmentation. Head spines were absent during the preflexion stages, being developed in the postflexion stage. The larvae occurred from the outer to middle reaches of the estuary, where temperature, salinity and turbidity ranged from 17.1 to 17.5∘C, 21.0–30.0 psu and 2–57 NTU, respectively. Data shows that L. maculatus utilize brackish waters of the estuary as a nursery for early stage development.