Benthic diversity in some derelict Waterbodies of Aligarh

Abstract

The organisms associated with solid liquid interface are ordinarily termed as Benthos (Haeckel, 1891). The term Benthos is derived from two Greek words and#8213;Ben meaning and#8215;the collection of organisms living in or on the sea or lakes and and#8213;Thosand#8214; and#8215;the bottom of sea or lakes . Hutchinson (1967) defined benthos as an association of species of plants and animals that live in or on the bottom of a body of water. Benthic fauna are especially of great significance for the fisheries that they themselves act as a food of bottom feeding fishes (Walker et al., 1991; Vijaykumar et al., 1991) forming an important part of the food chain. Benthos plays a critical role in the natural flow of energy and nutrients. As benthic invertebrates die, they decay leaving behind nutrients that are reused by aquatic plants and other animals. These animals are widespread in their distribution and can live on all bottom types, even on man made objects. They can be found in hot springs, small ponds and large lakes. Some are even found in the soil beneath puddles. Many species of benthos are able to move around and expand their distribution by drifting with currents to a new location during the aquatic phase of their life or by flying to a new stream during their terrestrial phase. Most benthic species can be found throughout the year, but the largest numbers occur in the spring just before the reproductive period. In colder months, many species burrow deep within the mud or remain inactive on rock surfaces. Many aquatic insects undergo a complete metamorphosis - the transition from egg to larva to pupa and finally to adult. They remain in the water for most of their lives (typically one month to four years). After becoming adults, the majority of insects live for only a brief time, usually a few hours to a few days, while they locate mates and reproduce. Among the invertebrate taxa, benthos are sensitive to pollutants such as metals and organic waste.