Population dynamics of Acentrogobius viridipunctatus (Actinopteri: Gobiidae) in the Vietnamese Mekong Delta

Spotted green goby Acentrogobius viridipunctatus is one of the commercial gobies living from brackish to freshwater globally, including the Southwest of Viet Nam, but there is no data on population biological traits used for assessing status of stock. Consequently, the research aimed to provide life history parameters of this fish like asymptotic length (L(∞)), growth coefficient indicator (K), exploitation rate (E), length at first capture (L(50)), the maximum age (t(max)), growth coefficient (Φ′), and mortalities. A total 960 individuals (528 males and 432 females) were caught using trawls at two ecoregions, including Tra Vinh-Soc Trang (TVST) and Bac Lieu-Ca Mau (BLCM), from January to December 2020. Results showed that average fish length was 8.0–11.0 cm, and L(∞) was 14.70 cm at TVST and BLCM. The von Bertalanffy growth curve was L(t) = 14.70 (1 − e(−0.73(t+0.27))) at TVST and L(t) = 14.70 (1 − e(−0.84 (t+0.23))) at BLCM, respectively. The Φ′ at BLCM (2.26) was higher than that at TVST (2.20), but t(max) at BLCM (3.57 yrs) was lower than that at TVST (4.11 yrs). The total mortality (Z), fishing mortality (F), and natural mortality (M) at TVST were 2.09 yr(−1), 0.29 yr(−1), and 1.80 yr(−1), respectively. These parameters at BLCM were larger than those at TVST, with values of 3.47 yr(−1), 0.34 yr(−1), and 3.14 yr(−1), respectively. The fishing status at TVST and BLCM was not subjected to overfishing as E in these regions (0.14 and 0.10) were lower than E(0.1) (0.76 and 0.72). Local authorities should ask fishers to increase fishing mesh size for sustainable exploitation.