River Catfish (Mystus sp.) is a fish that lives in the estuary area of the Blanakan River and has a high level of physiological adaptation to a wide salinity range. People consume River catfish. The study aims to determine the effect of salinity and Zinc (Zn) heavy metals at the water on the size distribution of river catfish. The fish samples were collected from 2 stations. The salinity was measured directly from water as well as the length and weight of fish. The Zn in water was measured by using AAS (Atomic Absorption Spectroscopy). The results showed that the value of salinity and Zn were 20 ppt - 29 ppt and 0.03mg/l – 0.22 mg/l, respectively. The fish length and weight were ranged 13.2 cm – 13.6 cm and 30.6-34.7 gr, respectively. Hence we conclude that the salinity and zinc variation has increased weight and length of river catfish.

河鲶鱼 ( Mystus sp.) 是一种生活在布拉纳坎河河口地区的鱼类，对广泛的盐度范围具有高度的生理适应能力。人们食用河鲶鱼。本研究旨在确定水中盐度和锌 (Zn) 重金属对河鲶鱼体型分布的影响。鱼样本是从 2 个站点收集的。盐度是直接从水中测量的，以及鱼的长度和重量。通过使用AAS（原子吸收光谱法）测量水中的Zn。结果表明，盐度和锌的值分别为 20 ppt - 29 ppt 和 0.03mg/l - 0.22 mg/l。鱼的长度和重量分别为 13.2 厘米 - 13.6 厘米和 30.6-34.7 克。因此我们得出结论，盐度和锌的变化增加了河鲶的重量和长度。