Differentiation of Freckled Goatfish Upeneus tragula Richardson, 1846 (Mullidae) in the Coastal Zone of Vietnam Based on Otolith Shape Analysis

Abstract

Abstract—The shape of otoliths (sagittae) is analyzed in freckled goatfish Upeneus tragula from South Vietnam (Gulf of Thailand), southern Central Vietnam (Nha Phu and Nha Trang bays), and North Vietnam (Ha Long Bay). The shape indices, elliptic Fourier analysis, and canonical discriminant analysis are applied. In the Gulf of Thailand, the samples off Hon Thom (Thom Island, An Thoi Archipelago, to the south of Phu Quoc Island) including the red morph and black morph collected during two subsequent years almost do not differ in otolith shape. A comparison of the samples from four regions of the Gulf of Thailand (40 km to the west of Phu Quoc, pooled sample off Hon Thom, coastal zone to the east of Phu Quoc, and 19 km to the west of Ha Tien) shows a discrimination of the stocks from the west to northeast. Substantial differentiation between the samples from Central and North Vietnam is not registered. The results are discussed in relation to the features of life history of U. tragula and possible relative isolation of some stocks.