Occurrence of Hypoatherina valenciennei (Bleeker, 1854) Post-larvae and Juveniles Collected at Estuarine Habitats of Northern Vietnam

Abstract

Development and distribution of Hypoatherina valenciennei are given based on 376 specimens of 6.6–24.1 mm body length caught from the Tien Yen and Kalong estuaries, Northern Vietnam from March 2013 to September 2015. Post-larvae and juveniles of H. valenciennei collected from Vietnam are elongated laterally compressed body, short trunk, compact gut and long tail. There were no spines on the head. Post-larvae had heavy pigment over the midbrain, on the dorsal surface of the gut and on mid-lateral surface, and did not arrange in a broken line, whereas juveniles had melanophores arranged in a broken line. Meristic values: D IV~V, I-8~10; A I,11~13; P1 I,5; P2 12–15. Preliminary data of otolith was first record in the present study. Sagitta was the largest otolith, whereas dimension of asteriscus became larger than lapillus with the development. The post-larvae and juveniles occurred primarily in rainy season from April to November when water temperature was from 21.7 to 30.2°C, and used outer parts of the Tien Yen and Kalong estuaries where salinity ranged from 5.2 to 21.0 psu as their nursery areas.