Landmark‐Based Morphometric Comparison of Juvenile Heteropneustes fossilis Reared in Pond and Recirculatory Aquaculture System

ABSTRACT

Monitoring fish juvenile growth parameters is crucial for optimising aquaculture practices, ensuring high survival rates and improving overall productivity. For Heteropneustes fossilis (stinging catfish), a species of significant economic and nutritional value in Bangladesh, understanding larval growth dynamics is essential for hatchery management, particularly given the challenges of climate variability and seed quality. Traditional growth assessment methods often lack precision, whereas landmark‐based morphometric analysis offers a robust, cost‐effective and reliable alternative for capturing subtle morphological variations influenced by environmental conditions. This study applied landmark‐based truss morphometric methods to compare the growth performance of H. fossilis juveniles reared in traditional pond systems and recirculatory aquaculture system (RAS) over a total culture period of 90 days. The analysis focused on 18 morphometric measurements and 23 truss distances to evaluate morphological differences between the two rearing environments. Results revealed significant variations, with RAS‐reared fish exhibiting superior growth, including greater total length (9.63 vs. 7.77 cm) and weight (5.35 vs. 4.20 g) compared to pond‐reared fish. Key morphological distinctions were observed in standard length, post‐dorsal length and anal fin length, with truss distances such as 2–5 and 5–11 showing the most pronounced differences. Principal component analysis (PCA) further confirmed these distinctions, with PC1 accounting for 59.08% of morphometric variance and 79.18% of truss morphometric variance. The findings highlight the advantages of RAS in providing stable, controlled conditions that enhance juvenile growth and morphological development. This study underscores the utility of landmark‐based methods in aquaculture research and supports the adoption of RAS for sustainable H. fossilis seed production, offering valuable insights for improving hatchery practices in Bangladesh and similar regions.