Ecology and biology of aquatic snails and their control: I. Comparative biology and development of five freswater snails from Assam
Abstract
Development biology of five parasitologically active aquatic snail species was studied in laboraory condition. The incubation period of Lymnaea (Psedosuccinea) acuminata f. rufescens (Gray), L. (Pseudosuccinea) luteola f. ovalis (Gray), Indoplanorbis exustus (Deshyes), Gyraulus convexiusculus (Hutton) and Segmentina trochoidea (Benson) were 9–12, 10–12, 89, 9–11 and 8–10 days, respectively. The first egg to egg cycle was 144–147, 142–145, 81–85 and 105–110 days for L. (P) acuminata f. rufescens, L. (P) luteola f. ovalis, G. convexiusculus land S. trochoidea, respectively. Field studies conducted in three wetland sites within a GPS marked location (26°05′ – 26°15′ N lat, 91°50′ E long) and an analogus map prepared based on remotely sensed satellite data (IRS-IB LISS 2A, FCC) revealed variation in population dominance of the five snail species over a one year time period. L. luteola f. ovalis and G. convexiusculus are naturally present throughout the year within a range of 5–10% prevalence rate. Two plateaus i.e. Septemper to November and February to July in reference to availability of L. acuminata f. rufescens, I. Lexustus and S. trochoidea population was recorded in the study area. There was species-wise variation in aestivation period and re-emergence of the snail population in the wetland.
Keywords
Assam, Aquatic snail, Biology, Satellite remote sensing
