Evaluation of gonads development of striped catfish (Pangasianodon hypophthalmus) in salinity condition

Abstract

Striped Catfish (Pangasianodon hypophthalmus) is one of the major freshwater fish species harvested across the Mekong River Basin and this species provides one of the largest and most important aquaculture in the world (FAO, 2010). However, there are not studies on the effects of salinities on reproductive development of the stripped catfish while Mekong Delta was predicted to strongly effects by salinity intrusion due to climate change. This study was conducted in College of Aquaculture and Fisheries, Can Tho University, Viet Nam from July/2018 to December/2019. Total of 10243 fish (average weight: 1080 ± 271 g/fish, at 12 month-age), produced from crossing 30 males and 30 females from three different provinces in Mekong Delta, were used in this study. These fish were separated for two groups such as 0 ppt and 5 ppt of salinity. All fish were used the same kind of foods and the same of water quality management. The samples were collected 3 time during experiment with schedule from 7-10 months/time according the gonadal development and used for histology analysis. There were a slightly difference between the weight of fish at 5 ppt (2287 ± 520 g/fish) and 0 ppt (2650 ± 235 g/fish) at 19 month-age. However, there were no difference in GSI (Gonado-somatic Index) index of females in both groups (0.22 for saline group and 0.24 for freshwater group). At 29 month-age, there were significant differences between eggs diameter of two group of fish (0.9 mm at 5ppt and 0.8 mm at 0ppt). The preliminary results of this study show that the striped catfish seem ability to reproduction in brackish water at 5‰ of salinity.