Introduction: What conservation problem or question does your study address?Ponds are the vital part of freshwater conservation and contribute to its biodiversity. Aquatic insects are the bio-indicators and bio-control agents. Very less study has been made on the aquatic insects of ponds in North East India. We have studied and compared aquatic insect diversity along with the physico-chemical properties of water of two ponds, one rural (j.pond) and one urban (u.pond) from Cachar and tried to analyse their role in biodiversity conservation.
Methods: What were the main research methods you used?Collections were done for the two seasons- Post monsoon (2013) and winter (2014). Aquatic insects were collected by Kick method and fixed with 4% formaline dehyde. It is then sorted and preserved in 70% ethyl alcohol. Insects were identified using standard literature keys and fifteen different physico-chemical variables of water were also analyzed following standard literatures.
Results: What are your most important results?A total of 3 Orders, 8 Families and 17 species from j.pond and 5 Orders, 17 Families and 29 species from u.pond were recorded. Shannon diversity index showed highest values in u.pond. Engelmann’s scale of dominance showed Cloeon dipterum as the eudominant species in u.pond. No eudominant species were recorded in j.pond. Values of dissolved oxygen, salinity, and potassium were found more in j.pond but nitrate and phosphate were found more in u.pond for both the seasons.
Discussion: What are your important discussion points and what is the relevance of your results to conservation (if any)?According to WHO and BIS all the variables of water were within the permissible limit in both the ponds for post monsoon but pH and salinity were found beyond the permissible limit only in j.pond during winter season. This resulted in maximum diversity of insects in u.pond though density of insects was higher in j.pond. Therefore along with rural ponds urban ponds are also playing a vital role in conserving the biodiversity of the freshwater ecosystems.