Abstract

• This study investigates the abundance and distribution of the endemic yellowtail catfish, Pangasius myanmar, within the Yangon River estuary. Fish data, including length and weight measurements, were collected through field observations and interviews. Surface water samples were collected using standard sampling procedures for laboratory quality analysis. Pearson's correlation coefficient was used to evaluate the relationship between fish length and weight. Field observations and interviews revealed that the species is widely distributed across the coastal, river mouth, and intertidal zones, extending up to 23 miles (38.34 km) upstream from the river mouth, which itself stretches approximately 40 miles (63.37 km). Seasonal variations in catch were noted, with increased captures upstream during the dry season and active fishing in downstream during the wet season, particularly in the brackish water zone where freshwater and saltwater converge. Remarkably, fishing activity yielded the highest catches near mangrove areas during high tides, with fishermen using lift nets to exploit the catfish’s foraging behavior. Over the study period from November 2023 to October 2024, a total of 2,839 fish were recorded, with monthly catches highest in November (475 fish) and reducing in May (75 fish). The total weight of the harvest reached 16,512.7 kg, with the highest monthly weight recorded in October (2,671.2 kg). The findings indicated the ecological significance of the Yangon River as a breeding and feeding habitat area for Pangasius Myanmar which is endemic species to Myanmar, Yangon Region. The correlation between fish length and weight is both strong and statistically significant, meaning that fish grow proportionally in both dimensions. This suggests healthy growth status in terms of both body length and weight. Fluctuations in water quality, particularly during the reproductive periods such as egg maturation in April directly influence the species' health and population viability. Therefore, the protection and appropriate fishery management of this estuarine ecosystem, which is rich in mangroves and salt marshes, is vital for the sustainability of the local fishery and the continued presence of this endemic species in the Yangon River.