Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

Size structure and exploitation pattern of Ailia coila (Hamilton, 1822) from the Ganga river at Allahabad, India.


Two stressors viz. fishing pressure and invasion of exotic species are the most alarming threat for economically important fish species of freshwater. The small sized minor catfish species belonging to family schilbeidae (order Siluriformes), contribute a major portion of the catches from rivers. Ailia coila is one of the small sized catfish, which is regularly found in the catches from river Ganga at Allahabad. However, the biology of this fish has not been studied so far. With an aim to study the present status of Ailia coila, the study on selected parameters of fish biology were undertaken from the catches of river Ganga and Yamuna river at Allahabad. The fish samples were obtained randomly during the months of July 2015 to June 2017 from the Ganga river at Allahabad. The collected fishes were grouped into different size group with 10 mm size interval. Exploitation pattern of the small catfish Ailia coila in river Ganga was studied. Maximum exploitation was recorded in 141-150 mm size group with 16.22% and minimum in 91-100 mm size group with 3.68% in the collected samples. In the wake of diminishing population of indigenous fish groups of river year after year, the exploitation pattern indicated that the middle sized group fishes are overfished as they are preferred fish used as cheap food by fishermen and consumers. It was observed that middle sized groups of fish stock of mature fishes is very healthy in the Ganga river at Allahabad, India.