First report on morphometrics, length–weight relationship, feeding habit, and diet composition of Trichopodus trichopterus from Tra Su, An Giang, Vietnam

Abstract This study aimed to provide preliminary biological data on Trichopodus trichopterus (Pallas, 1770), an ecologically and economically essential freshwater species in the Mekong Delta, focusing on its external morphology, growth pattern, feeding habit, and diet composition. Specimens were collected from Tra Su (An Giang Province) in March 2025 and analyzed in the laboratory. Morphometric analysis revealed that fin ray counts were relatively stable, with caudal fin rays ranging from 14 to 16, pelvic fins with 1 ray, dorsal fins with 5–7 spines and 6–10 soft rays, anal fins with 11 spines and 30–35 soft rays, and pectoral fins with 8–12 rays. The length–weight relationship showed isometric growth, with a growth coefficient of b = 2.98 ± 0.16 and a positive relationship ( r 2 > 0.93). The digestive system exhibited typical traits of an omnivorous species, including a superior mouth, small conical teeth, and gill rakers adapted for filtering plankton. The relative gut length ( RGL = 2.19 ± 0.09) further supported its omnivorous classification. Stomach content analysis revealed a diverse diet dominated by fish eggs (45%), zooplankton (33.99%), and algae such as Chlorophyta, Cyanophyta, and Bacillariophyta. These results contribute to foundational knowledge for taxonomy, ecological monitoring, and the development of artificial breeding strategies and sustainable fisheries management in the Mekong Delta. Clinical trial registration : This study does not involve any clinical trial.