great pond snail

LC - Least Concern

N5 - Secure

S5 - Secure

not listed

Great pond snail is a very large, air-breathing, freshwater snail. It occurs in Europe, Asia, North America, and southern Australia. It occurs throughout the United States and Canada, but it is uncommon south of the 40th parallel. It is common in Minnesota. It is found in permanent, slow or still waters, usually with dense vegetation, including creeks, streams, rivers, marshes, swamps, and reservoirs, and at the edges of lakes and large ponds.

Great pond snail is commonly sold as an aquarium pet. It has recently become the subject of scientific research into handedness (chirality).

Adults can be 1¾″ to 2¾″ (45 to 70 mm) long and ¾″ to 13⁄16″ (20 to 30 mm) wide, but they are usually no more than 2¼″ (56 mm) long.

The shell is thin and fragile. It has 4½ to 6 complete (360°), weakly convex rotations (whorls). The last whorl (body whorl) above the opening is suddenly and greatly inflated. The remaining whorls are elevated and gradually reduced in size, forming a long, sharply pointed spire. When seen with the tip at the top and the opening facing up, the opening is on the right side. This is referred to as an elevated spire, right-handed, shell. There is no door-like structure (operculum) covering the opening of the shell. The shell base color is variable, from tan to dark brown. It has no obvious markings. A cavity within the shell has an air bubble that is refreshed every time the snail rises to the water surface to breathe.

The head is divided into two flat lateral lobes at the end. There is a single pair of sensory tentacles on the head and a small eye at the base of each tentacle. The tentacles are flat, wide, and triangular. The body contains both male and female reproductive organs (hermaphroditic). During copulation either the male role or the female role can be performed, though not both.

1¾″ to 2⅜″ (45 to 60 mm) long

Permanent, slow or still waters; creeks, streams, rivers, lakes, ponds, reservoirs, marshes, and swamps.

Although it can inhale oxygen from the water, it frequently moves to the surface to breathe. An air bubble is maintained within the shell and is refreshed at the surface of the water.

Algae and decaying submerged aquatic vegetation

Sources

4, 24, 29, 30.

Common

The family Lymnaeidae was formerly placed within the suborder Basommatorpha. In 2005 the family Lymnaeidae was placed in the superfamily Lymnaeoidea within the Pulmonata, an informal grouping, which was placed within the Basommatorpha, which became another informal grouping. In this ranking there is no order or suborder. A recent comprehensive molecular phylogenetic analysis of the superorder Hygrophila (Saadi, et al., 2020) placed all members of the superorder in two superfamilies, Lymnaeoidea and Chilinoidea, eliminating the informal groupings.

Four subsecies have been recognized, but these are not widely accepted.

9/11/22

Found on the shoreline in a mound of seaweed.

1 5/8 inches long

Location: Lake Shore, MN

9/11/22 Found on the shoreline in a mound of seaweed. 1 5/8 inches long