Estimation of relative growth of Minor carp Labeo bata (Cyprinidae) through multi‐linear dimensions

Abstract

This study focuses on relative growth through length‐weight relationships (LWRs) and length‐length relationships (LLRs) using a total of 15 linear dimensions of Minor carp Labeo bata (Hamilton, 1822) from the Ganges River, northwestern (NW) Bangladesh. Also, meristic counts covering various fin rays and scales from different body parts (including lateral line scales) of L. bata (Hamilton, 1822) have been studied. A total of 300 individuals of L. bata were sampled occasionally from the Ganges River from July 2013 to June 2014, using various traditional fishing gears (e.g., Cast net, Gill net and Square lift net). Number of fin rays from all fins and scales were counted using magnifying glass. Additionally, a total of 15 different lengths were measured to 0.1 cm and whole body weight (BW) was taken to the nearest 0.1 g for each individual. Fin formula of L. bata is as follows: dorsal, D. 10–12 (i–ii/9‐10); pectoral, P1. 12–16 (iii–iv/9–12); pelvic, P2. 9 (i/8); anal, A. 6–7 (ii/4–5); and caudal, C. 20–24 (iv–vi/16–18), respectively. Minimum and maximum lengths were found as 8.0 to 25.1 cm in total length (TL) and body weight (BW) ranges from 4.8 to 161.0 g. All LWRs were highly significant (p < .001) with r2 values ≥0.960. Based on r2 value, LWR by BW versus TL was the best fitted model among 13 equations. In addition, the LLRs were also significant with r2 values ≥ 0.959. According to r2 value, LLR by TL versus FL was the best fitted model among 15 equations. This study would be very effective for species identification and stock assessment in the Ganges River, NW Bangladesh and surrounding ecosystems.

Temporal variations of length, weight and condition of the Asian stinging catfish Heteropneustes fossilis (Bloch, 1794) in the Ganges river (NW Bangladesh)

“…The maximum length of H. fossilis recorded as 28.7 cm TL in our study, which is lower than the maximum known TL of 31.0 cm, in the Ganga River, India (Khan et al, 2012) but higher than the maximum TL of 26.8 cm found in Gajner beel, a wetland ecosystem of Bangladesh (Rahman et al, 2019). Maximum length information is required to assess population parameters, in addition to asymptotic length (L∞) and fish growth consonant, which is crucial for the strategic planning of fisheries resources (Hossain et al, 2012).…”

“…Additionally, it measures fish well-being quantitatively and forecasts population success in the future (Richter, 2007;Hossain et al, 2013;2016). Moreover, the relative condition factor (KR) can be used to examine fish health (Rypel and Richter, 2008;Hossain et al, 2009; 2013) as well as very important to estimate the environmental condition of fishes (Hossen et al, 2019).…”

Life‐history traits of three Ambassid fishes (Chanda nama, Parambassis lala and Parambassis ranga) from the Mathabhanga River, southwestern Bangladesh

“…This finding is in accordance with the findings of the present study. Information on the maximum length is necessary to estimate the population parameters, including asymptotic length and fish growth coefficient, which is important information needed for fisheries resource planning and management (Hossain, Sayed, et al, 2015; Hossen, Paul, et al, 2019; Hossen, Rahman, et al, 2019).…”

New maximum size record, length–weight relationships and form factor of Hooghly Croaker Panna heterolepis Trewavas, 1977 from the Bay of Bengal (Bangladesh)

“…Length–weight relationships (LWRs) are essential for studying fish stock assessment and population dynamics (Hossain, Hossen, Ahmed et al, 2017; Parvin et al 2018; Hossen, Rahman, Hossain et al, 2019), allowing calculation of weights consistent with a given body length. It is widely used in analyses of fishery data, mainly because of the difficulty and time required to record weights in the field (Andrade & Camos, 2002).…”

“…This relationship is often used to convert growth‐in‐length equations for predicting weight‐at‐age and use in stock assessment models (Pauly, 1993). It is also useful for comparison of morphological traits among species, or among population, of certain species from various habitats and/or areas (Hossain, Rahman, Abdallah et al, 2013; Hossen, Rahman, Hossain et al, 2019). At the same time, form factor ( a 3.0 ) is widely used to compare fish body shapes between geographic locations (Froese, 2006).…”