Median Lethal Salinity (MLS96 h) of Two Small Indigenous Fish Species Amblypharyngodon mola and Pethia ticto from Indian Sundarban

Dubey Sk Trivedi Rk

doi:10.4172/2155-9546.1000249

Abstract

Amblypharyngodon mola and Pethia ticto are small indigenous fish species belonging to family cyprinidae and considered as primary freshwater fish widely distributed in Indian subcontinent including Sundarban region. The 96-h median lethal salinity (MLS96 h) level of these fish was found out by exposing to saline water (0-10 ppt) in direct transfer method. The 96-h median lethal salinity for A. mola was found to be 6.20 ppt with 95% confidence intervals of 4.38-7.09 ppt where as for P. ticto it was 6.12 with 95% confidence intervals of 3.67-7.07 ppt. The Probit showed that at 6.12-6.20 ppt, 50% of the both test species shows sensitivity to salinity that leads to mortality. The regression analysis indicated that the mortality rate is positively correlated with salinity concentration having a regression coefficient close to 1.0 in each case. Various levels of external stress responses were noticed at 8 and 10 ppt salinity. The study suggests that these fish can potentially be used as a candidate species for aquaculture in slight brackishwater areas of Sundarban. However, further studies are required to understand the ecosystem based adaptation processes at higher salinity levels.

Highlights

Amblypharyngodon mola and Pethia (Puntius) ticto are conspicuous member of small indigenous fish species (SIS) belonging to the family cyprinidae and considered as native primary freshwater fish species
The cumulative mortality (%) at different time intervals and percentages of the survivors of A. mola and P. ticto exposed to different salinity concentration are presented in Table 2 and Table 3 respectively
The investigation from the present study indicate that two small indigenous fish species (SIS), A. mola and P. ticto inhabiting freshwater areas of Indian Sundarban complex can tolerate within a very narrow range of low salinities

Summary

Introduction

Amblypharyngodon mola and Pethia (Puntius) ticto are conspicuous member of small indigenous fish species (SIS) belonging to the family cyprinidae and considered as native primary freshwater fish species. These tropical Asian cyprinids are well distributed in Indian subcontinent including Sundarban region of West Bengal and commonly inhabit ponds, rivers, floodplain lakes, low lying swamps, marsh lands, canals, paddy fields and many other small water bodies etc [1,2,3]. Salinity tolerance is an important consideration in the culture of marine and freshwater organisms providing information about basic culture requirements necessary for the species to thrive in captivity as well as potential applications for assessing the distribution of fish and their impact on ecosystems [9,10]

Methods

Results

Conclusion