Association pattern between dimensions of fish and otolith to expedite morphometric variations of three geographically isolated stocks of Tenualosa ilisha (Hamilton, 1822) from diverse ecosystems

Abstract

An attempt was made to establish association pattern between dimension of fish and otolith to expedite morphometric variations of geographically isolated stocks of Tenualosa ilisha (Hamilton, 1822), from three diverse ecosystems; viz., an estuarine (brackish water), a riverine (freshwater) and a lacustrine (freshwater) ecosystem. Sampling was carried out during the period from September 2017 to February 2019 and a total of 196 otoliths were sampled from Narmada Estuary (n=69), Brahmaputra River (n=75) and Ukai Reservoir (n=52) of India. Mean otolith length recorded was 3.55±0.14 mm, 5.18±0.09 mm and 3.85±0.07 mm for samples collected from Narmada Estuary, Brahmaputra River and Ukai Reservoir respectively. Otolith length-weight relationship (OLWR) from three ecosystems showed negative allometric b values ranging from 1.9046-2.5048, with significant difference between Narmada Estuary and Brahmaputra River (p<0.05). Power regression analysis of otolith dimensions (length and width) to total length of fish (TL) and otolith length (OL) to total weight of fish (TW) showed that data fitted well to the model as evident from R2 values (>0.6); except for relationship between otolith width (OB) and TL in samples from Brahmaputra River (R2=0.459). Present study provides first-hand information on association pattern of dimension of fish body and otolith of T. ilisha which can be used in geographical mapping of stock profile of the species.

Size-specific variations in the length-weight relationship and relative condition factor of Hilsa shad (Tenualosa ilisha) across its habitats in Bangladesh

“…Our findings for the b value ( b = 3.110) from the pooled sample and are corroborated with previous studies from water areas in Bangladesh (mean b = 3.20; range: 2.82–3.51) ( Table 3 ). Moreover, the mean b value estimated from the pooled sample of Hilsa from the different aquatic ecosystems of India and Myanmar is similar to our current findings [ 33 , [56] , [57] , [58] , [59] ].…”

“…2018–Jun. 2019 P 88 16.2–40.3 0.011 2.96 0.96 I 1.00 ± 0.01 0.697–1.138 [ 58 ] Chilika lake Jan.–Dec. 2014 P 497 17.5–50.2 0.017 2.99 0.94 I [ 72 ] Hooghly estuary Sep.–Nov.…”

“…2018–Jun. 2019 P 326 8.1–56.2 0.007 3.09 0.99 PA 1.01 ± 0.01 0.72–1.31 [ 58 ] Padma river Nov. 1999 P 90 22.5–51.0 0.012 2.97 0.94 I 1.01 ± 0.13 0.62–1.38 [ 33 ] Nov. 1999 M 35 22.5–43.5 0.030 2.69 0.89 1.02 ± 0.16 0.68–1.36 [ 33 ] Nov. 1999 F 55 26.0–51.0 0.013 2.97 0.97 0.98 ± 0.09 0.80–1.17 [ 33 ] Nov. 2015 P 85 16.5–30.0 0.028 2.63 0.88 I 1.02 ± 0.11 0.59–1.33 [ 33 ] Sundarban estuary Jun. 2011–Mar.…”

Morpho-Genetic Divergence and Adaptation of Anadromous Hilsa shad (Tenualosa ilisha) Along Their Heterogenic Migratory Habitats

“…Moreover, the overall size of Hilsa shad depicted by body depth, head length and anal fin length, are highly dependent on the seasonal migratory behavior (Dwivedi, 2019b). During monsoon season (July to October), fish with deeper body profile are found commonly at mature adult stage, dominate the freshwater habitats, while individuals with slender body profile remain in estuarine and marine environments (Borah et al, 2019;Dwivedi, 2019b). These morphogenetic differences among heterogeneous habitats are confounded by variation of environmental parameters and seasonal life-stages, preventing us from concluding firmly as to whether these differences are of exclusively plastic.…”

Understanding the breeding phenology of anadromous fish Tenualosa ilisha (Hamilton, 1822) in relation to climatic variables in Brahmaputra River, India

“…The species is also reported from rain-fed peninsular rivers like Narmada and Tapti and their estuaries (Bhaumik and Sharma, 2012) draining into the Arabian Sea. The rivers Hooghly, Brahmaputra, and Ganga and their tributaries contribute around 70% of total Hilsa catch in India (Raja, 1985;Borah et al, 2019a;Borah et al, 2019b). Although widely distributed along the Indian coast, it forms a commercial fishery in the north-east coast of India comprising the states of West Bengal and Orissa.…”