Estimation of population parameters for a data deficient Salmostoma bacaila (Hamilton 1822) stock from the Mahananda river (tributary of the Ganges) in NW Bangladesh

Abstract

Salmostoma bacaila known as Razorbelly minnow (Hamilton in 1822) is an indigenous fish species in Bangladesh. This study emphasizes on population structure, growth pattern (length-weight and length-length relations), growth considerations (asymptotic length, L_∞; weight, W_∞; growth coefficient, K; age at zero length, t₀), size and age at sexual maturity (L_m), growth performance index (φ), life-span (t_max), conditions factor (Allometric, K_A; Fulton’s, K_F and Relative, K_R), prey-predator status through relative weight (W_R), form factor (a_3.0), total (Z), natural (M) and fishing mortality (F), exploitation rate (E) and maximum sustainable yield (MSY) of S. bacaila in the Mahananda river, northwestern Bangladesh. Total 305 specimens of S. bacaila were hardly sampled (ranging between 5.5 to 11.9 cm total length (TL), and 1.05 – 9.20 g total body weight (BW)) through regular fishing gears during August 2016 – July 2017. The regression coefficient ‘b’ of length-weight relations specified negative allometric growth. Growth parameters (GP) were figured as L_∞ = 12.66 cm, K = 0.60 year^-1, W_∞ = 11.36 g, t₀ = 0.048, t_max = 5.00 year^-1 and φ’ = 1.98. The L_m was 7.34 cm in TL. Relative weight did not create any significant dissimilarity of 100 that would suggest a healthy habitat for S. bacaila. The a_3.0 was 0.0052 specifying that this fish could be described as elongated. In addition, the Z was calculated to be 1.57 year^-1. The M and F values obtained were 0.92 and 0.65 year^-1, respectively. The E was 0.41 and MSY (E_max) was estimated as 0.35 year^-1 by yield per recruitment model. Present research knowledge will be very useful in planning the sustainable and appropriate management of this species in Bangladesh and bordering countries.