Demography of Two Fishes Xenentodon cancila (Hamilton, 1822) and Hyporhamphus limbatus (Valenciennes, 1847) From Ujani Reservoir (Maharashtra, India) Facing Multiple Threats

Abstract

The species representing minor fisheries are gaining more economic importance as fishing pressure is increasing on major riverine fishes. Population characteristics or demographic studies of minor fishery resources can provide insight into the impact of environmental issues, conservation status, and help in the management and development of fisheries. We studied the population dynamics of two commercially significant fishes, freshwater garfish, Xenentodon cancila and Cangaturi halfbeak, Hyporhampus limbatus, from Ujani water reservoir (Pune, India) using cast net and gill net on a monthly basis for 1 year. Length-weight relationship (LWR) and population dynamics of both fishes were analysed using FAO-ICLARM Stock Assessment Tool (FISAT). LWR analysis revealed a positive allometric growth pattern in both X. cancila (b = 3.12) and H. limbatus (b = 3.15). The estimated potential longevity (t_max) of X. cancila and H. limbatus was 3.48 and 5.76 years, respectively. The observed length at first capture for X. cancila and H. limbatus was 18.53 and 6.66 cm, respectively. Juveniles of H. limbatus face higher exploitation as compared to X. cancila. Higher natural mortality was observed in X. cancila while fishing mortality was higher in H. limbatus. Recruitment analysis revealed two spawning bouts in 1 year for both species. Xenentodon cancila fish stock is under-exploited and H. limbatus fish stock is over-exploited in Ujani reservoir. Further reproductive biology studies are necessary for the effective development and management of fisheries involving X. cancila and H. limbatus.