Morpho-meristic parameters, length-weight relationships and condition factor of three ambassid fishes from Chalan Beel, Bangladesh

Length-weight correlations and condition measures are important in fish biology to determine individual health and potential variations among stocks of the same species. Length-length, length-weight relationships, morpho-meristic characteristics and condition factor were documented for three small indigenous species (Chanda nama, Parambassis lala and Parambassis ranga) equally totaling 600 individuals collected in ‘Chalan Beel’ using a seine net (mesh size 0.5-1cm) from July 2020 to December 2020. Body weight was determined with an accuracy of 0.01g, and length was calculated to the nearest 0.1cm. The mean body weights of C. nama, P. lala and P. ranga were calculated as 1.75±0.61g, 0.55±0.16g and 0.88±0.31g and their average total lengths were 5.50±0.68cm, 3.18±0.28cm and 3.71±0.42cm, respectively. Standard morphometric and meristic traits were found throughout all three studies species and a strong relationship between length and weight (P 0.05) was observed. The final ‘b’ values for TL and BW were recorded at 2.52, 3.03 and 3.14 for C. nama, P. lala and P. ranga, respectively, indicating negative allometric growth for C. nama, isometric growth for P. lala and positive allometric growth for P. ranga. Furthermore, condition factors ( 1) demonstrated that these species were in excellent condition in their natural habitats. The present observations would be an effective tool to help identify these fish species in varied aquatic environments across Bangladesh and nearby regions, enabling their optimal management and conservation.