Ecology of snail

Important ecological parameters are habitat, water, soil, migration, life span and physiology. These are briefly described below:

Habitat: Genera and species of pulmonate snails differ in their choice of habitat. Pulmonates snails require slight water current, minimal pollution, aquatic vegetation and low salinity. Dissolved gases, mineral salts and organic materials have a local influence on the survival and multiplication of snails. Pectinibranchiate prefer shaded or moist ground, edges of streams in low, flat alluvial plains suitable for lowland farming and rice culture. They require shade, moist soil decaying vegetable matter and a fluctuating water level.

Water: Snails of both groups can survive under water for several weeks, but prefer to live on the edges of water. They do not move in a definite direction and do not always leave the water. Some creeping along the edges of water and others in and out of the water. Their activity is influenced by the pH and temperature of the water.

Soil: Both groups of snails burrow in the mud to protect themselves against desiccation and is associated with hibernation; some may burrow up to 40cm in depth. Hibernation is influenced by fall in temperature below 25⁰C, fall in water supply and availability of nutrients.            

Migration: is associated with current and temperature.They do not wander far from their suitable habitats until inadvertently carried by the current.

Growth: The rate of growth in snails is greatly influenced by the supply and availability of food and influences size and time of maturity. Snails attain maturity within 2-12 months time. They usually die within few weeks of cercarial release, some may survive up to 2 years.

Physiology: Oxygen is required for normal functioning of all snails, their activity regarding reproduction  and shedding of cercarriae is influenced by oxygen tension, temperature and light. Anaerobic conditions reduce shedding cercarriae. Snails produce 30 to200000 eggs in her life time, and these hatch within 3 weeks to 3 months. But both production and hatching is also influenced by above physiochemical factors. Light of different wave lengths produce various phototactic reaction. Some snails are bottom feeders but others are surface feeders.