Evaluating Biometric Indices and Life History Traits of Indian Glassy Perch, Parambasis ranga: Implications for Sound Management

The current study described the biometric indices and life-history traits, including population structure, growth pattern, condition factors, form factor (a3.0), size at first sexual maturity (L_m), natural mortality (M_W) and optimum catchable length (L_opt) of Parambassis ranga from three culture management systems (S1, S2 and S3) in the Oxbow Lakes, southwest Bangladesh. Fish samples (n = 2415) were harvested (January-December, 2021) using cast, push and gill nets. S1 comprises the Baors of Boluhor and Joidia; S2 comprises the Baors of Nasti and Porapara and S3 comprises the Baors of Kushna and Jagodishpur. Specimen’s total lengths (TL) spanned from 2.40–4.60cm for S1, 2.30–4.51cm for S2 and 1.90–3.90cm for S3, respectively. The length-frequency distributions (LFDs) revealed that the size groups with 3.6–3.7cm TL for S1, 3.0–3.10cm TL for S2 and 2.80–2.90cm TL were numerically dominant. The growth pattern for S1 was found to be positive allometric based on the length-weight relationships (LWRs), while S2 and S3 showed negative allometric growth. Allometric, relative, Fulton condition parameters and relative weight (K_A, K_R, K_F and W_R) showed positive associations (P< 00.05) using correlation assessment suggesting that the species are performing well. Among all the three condition indices, the Fulton condition factor is highly used and is the prominent condition factor among all three condition indices. The L_m values for S1, S2 and S3 were 3.0753, 3.0143 and 2.6442cm TL, respectively, based on the maximum length (L_max). Furthermore, for S1, S2 and S3 the M_W values were 1.72, 1.91 and 20.05/year correspondingly. The outcomes of this investigation would be extremely helpful for managing P. ranga in the three management systems and in the southwestern Bangladeshi Oxbow Lakes in an efficient and sustainable manner.