Six New Snail Species Recorded in Bantam Lake

The wetland habitats across the White Memorial Foundation are home to a vast array of plants and animals. Some, such as sunfish and red-winged blackbirds, are quite noticeable and attract a great deal of attention.  There are other less noticeable groups of species, however, that play a very important role in wetland ecosystems.  One of these groups are freshwater snails.

The large Chinese Mystery Snail was introduced from Asia as
a source of food.  It is now established across North America,
and can be found in the Bantam Lake watershed.

The slow-moving, dull-colored snails can be easily overlooked, but they play a vital role in wetland ecosystems.  They eat algae, plankton, and decaying plant and animal material, recycling nutrients back into the animal community.  Snails, in turn, are eaten by turtles, fish and birds, providing them with an important source of food.  Snails are also intermediate hosts for parasitic flukes, a type of flatworm that can infect both people and wild animals. (In the Northeastern US, snails serve as intermediate hosts to Swimmer's itch and Lung fluke.  There are many more that affect people in the tropics, including schistosomiasis, which is  the second most socioeconomically devastating parasitic disease after malaria.)

Because snails are so easily overlooked, we know relatively little about their distribution in the State.  Eileen Jokinen, a former University of Connecticut researcher, conducted a statewide snail survey in the late 1970s.  However, snails can easily move from one waterbody to another by attaching to boats or animals.  With so much boating and wildlife activity on the property, we thought, it was only a matter of time before new snail species moved into the Bantam Lake watershed, making Jokinen's inventory obsolete.  To get more recent data on our snail species, we decided to join Laura Saucier, a CT DEEP wildlife biologist, in collecting and identifying some local snails.

A bladder snail (Physella sp.) This is one of two snails that
both Eileen Jokinen and ourselves found in Bantam Lake.

As soon as we started collecting snails, we knew that things had changed since Jokinen's work several decades ago.  Jokinen had collected five snail species from Bantam Lake.  On our first day collecting at the Litchfield Town Beach, we collected six species.  Out of these six, only two were recorded by Jokinen. 

Over several visits, we recorded six new species for the Bantam Lake watershed.  One of these, the banded mystery snail (Viviparus georgianus) had previously been found in only two lakes in Connecticut, East Twin Lake and Lake Waramaug.

Banded Mystery Snail
(Viviparus georgianus)
 

There are several features we look for in identifying snails.  One of these features is an operculum.  An operculum is a hard disc-like trapdoor structure that protects the snail when it retreats into its shell.  The operculum is visible in the picture of the Banded Mystery Snail above (the brownish structure in the lower part of the shell's opening, or aperture).  However, the Bladder snail in the top picture has no operculum. 

Another feature we look at is the aperture, or opening, of the shell.  In some snail families, the opening is on the right side of the shell.  This is called a dextral aperture, and can be seen in the Banded Mystery Snail above.  When the opening is on the left side of the shell, as in the Bladder snail, it is referred to as "sinistral".

Shell shape can vary between types of snails.  The Planorbidae family, for example, has a shell shaped like a ram's horn, while most other snails have a cone-shaped shell.




Marsh Ramshorn
 (Planorbella trivolvis)

We also decided to sample several other ponds on the property in addition to Bantam Lake.  We found several species of snails in Ongley Pond, Heron Pond, Plunge Pool, and Beaver Pond.



The Pointed Campeloma (Campeloma decisum) was very common in
Bantam Lake, Ongley Pond, and Beaver Pond.  However, Jokinen had
no record of this species in Bantam Lake when she conducted her survey.
 

Even though we only spent a couple days collecting aquatic snails, we more than doubled the previous number of known snail species on the property.  Imagine what we could learn if we invested several weeks into this process!  On top of the aquatic snails we were collecting, we also have terrestrial snails and marsh-dwelling snails that we know very little about.  There is so much we don't know about these common but unassuming creatures.