Biometric studies of Ailia coila (Hamilton, 1822) from river Brahmaputra, Assam, India

Abstract

For the study of length-weight relationship, morphometric and meristic characters, a total of 711 specimens (196 male and 515 female) of the Gangetic ailia, Ailia coila (Hamilton, 1822) were collected from Uzanbazar and Dhubri landing centres of river Brahmaputra, Assam during September 2013 to April 2014. The length and weight of males ranged from 66 to 154 mm and 1.218 to 20.5309 grespectively and that of females ranged from 66 to 161 mm and 1.4344 to18.2907 g respectively. The length-weight relationship was established as W = 0.002773 L 3.189306 and W = 0.005794 2.86234 for male and female, respectively. The analysis of covariance showed significant difference in ‘b’ values between sexes and student ‘t’ test indicated positive allometric growth for male and isometric growth for female. The morphometric characters were compared; showed maximum co-efficient of correlation (r) in standard and pre-dorsal length (0.98) while lowest was observed in mandibular barbel length (0.69) against the total length. Based on the study of meristic traits, the fin formula can be written as B6, P12-15, V5-6, C14-18, A61-75, GR17-24. The minor variations in meristic and morphometric characters could be attributed to genetic components and difference in geographical and environmental parameters like temperature and food availability. The study will helpful in identification of stock and stock-specific management strategies of this species in river Brahmaputra, Assam.

Life History Traits of Gangetic Ailia Ailia coila (Hamilton 1822) in the Tetulia River, Southern Bangladesh

“…In this scenario, the estimated b value of the LWRs (TL vs. BW) was 3.18, indicating that the population precisely follows the growth in a positive allometric pattern. Parallel research findings (b = 3.42) were observed from Panchet Reservoir in the Ganges basin, Jharkhand, India (Sandhya et al, 2020), from the Brahmaputra River, Assam, India (b value was 3.19 for males) (Gogoi et al, 2019) and ponds along the Ganges Varanasi (b = 3.65) (Mahapatra et al, 2018). An isometric growth pattern was observed (b = 3.07) in the Padma River in northeastern Bangladesh (Hossain, 2010).…”

“…Later, the morphometric differentiation and stock structure of this small native fish were studied by Bhutia et al (2019a, b). A biometric study of the fish was carried out by Gogoi et al (2019) from the Brahmaputra River in Assam. In molecular biology, the complete mitochondrial genome of this fish was studied by Alam et al (2019).…”

“…The river also plays an important role in the economic well-being of the people and in alleviating poverty by creating employment opportunities . There is no report on the study of the nutrientrich A. coila from the Tetulia River, although some scientific studies on length-weight relationship, condition factor, biometric analysis and mortality parameters (Hossain et al, 2009;Hossain, 2010;Mortuza and Al-Misned, 2015;Deori et al, 2017;Mahapatra et al, 2018;Gogoi et al, 2019;Mortuzaet al, 2020;Sandhya et al, 2020;Gogoi et al, 2021) have been conducted on this species. However, there are still no detailed scientific studies on the whole life history with a special focus on this species, which attracted our attention.…”