Critter

Aquatic Snails

Image of Aquatic Snails

Common name: Aquatic Snails

Scientific name: many different species
Phylum: Mollusca
Class: Gastropoda
Habitat: most shallow freshwater habitats, including ponds, lakes, creeks, rivers, and vernal pools
Size: less than 12.5 mm long

Description: Freshwater snails are not as colorful as their saltwater cousins. In general, their shells come in shades of gray, brown, and black, often with flecks of yellow or white.

Vernal pools have their own species of aquatic snails. Two aquatic snails are often seen in ponds and creeks of the Sacramento area. One is shaped like a flat spiral, and the other looks like a turban. Sticking out under the shell is the “foot”. The foot is fleshy and muscular; it allows the snail to move around. The foot extends to a head, with two tentacles on it like antennae. The eyes are located on or near these tentacles.

Fun facts: In preparation for the dry summer, the snails burrow several inches into the mud and seal themselves in mucus to prevent water loss. They can stay like this for up to three years!

Life cycle: Eggs are laid in jelly-like capsules on rocks or plants at the water’s edge. When the eggs hatch tiny snails emerge. They gradually grow to adult size.

Ecology: Using a long, rough tongue, the aquatic snail scrapes organic material, like algae and detritus, into its mouth. The snails serve as food for many different animals. Common predators include ducks, shore birds, amphibians, and aquatic insect larvae. In lakes and streams, fish often eat them.

Investigate

Little is known about the aquatic snail species that live in vernal pools. Do you think snails could travel across the grasslands from one pool to another without drying out? What ways can you think of that aquatic snails could get from one pool to another? Could other animals in the vernal pool grassland ecosystem carry them as they travel from pool to pool?

Commands