Demographics of Blue-spotted Mudskipper, Boleophthalmus boddarti (Pallas, 1770) from Mudflats of Sundarbans, India

Abstract

The Sundarbans Delta, one of India's Ramsar sites, is an ecologically important wetland that is home to a variety of endemic and threatened aquatic species, including mudskippers. However, there is a knowledge gap about their fundamental aspects, such as population dynamics, reproductive biology and other life-history characteristics, which hindered their conservation. Therefore, the demographics of the blue-spotted mudskipper Boleophthalmus boddarti (Pallas, 1770) were estimated. A total of 975 mudskipper individuals were collected during January 2018-December 2018 using a range of fishing gears [scoop net (0.5?2 cm mesh), bag net (5?15 cm mesh), fish traps (5 ? 5 cm mesh traps) and cast net (6?8 cm mesh)] with the help of artisanal fishers. Length?weight relationship analysis revealed negative allometric growth (b = 2.82) pattern for the study species. The estimated demographic parameters of study species are as follows: Asymptotic length; (L?) = 220 mm, growth coefficient (K) = 0.75 year?1, growth performance index (?) = 2.56 and potential longevity (tmax) = 4.0 years. The natural mortality rate (M = 1.58 year?1) of fish species was higher than the fishing mortality rate (F = 0.25 year?1). The current level of exploitation (E = 0.10) was much lower than the expected maximum rate of exploitation (Emax = 0.53), which indicates that the species is rationally exploited without any imminent danger of over-harvesting. The baseline data provided here likely to have implications for conservation and fisheries management of blue-spotted mudskipper.