Descriptive
Information
- Field Marks:
- Adult
- Round, smooth, apex blunt.
- Greenish/brown in color
with darker brown bands
- Breath through gills while they are in the water, and
with primitive lungs on land.
- Opening at end of apex is large and round
- Has 2 large antenna-like tentacles
- Egg Cases
- Very small
- White to light pink in color
- Laid in linear clusters like corn-on-the-cob
- Shaped in a slight teardrop fashion, similar to a corn
kernel
- Size:
- Shell of adults range
from 1.5 to 2 inches in diameter
- Eggs are approximately 0.5 cm.
- General
Habitat: Marsh vegetation and grassy, wet areas
- General
Range: Peninsular Florida
- Field Observations:
Our main focus of study was not just the adult apple snail, but
also the egg deposits. Eggs are laid in linear clusters, ranging
from straight lines to curved or diagonal, and are only found on
the Lance-leafed arrowhead plant. These plants are approx. 3 feet high, with
3 petals per white flower. It was interesting to note that arrowhead
plants grew in the depressions created close by limestone bedrock,
but not farther out in the marsh muck. Arrowheads are a thick-stemmed
plant, flattening to a broad oblong leaf at the top. Apple snails
lay their egg clusters
on the stems, about 6" to1' off the low water line, however,
there is no apparent side of the stem that egg clusters were predominantly
found on. Egg cases are attached to the stalk with a mucus membrane,
that dries and forms a glue-like reside on the plant, creating a
cementing base. This is not a particularly strong bond, as the egg
cases can easily be knocked off. In a 20 sq. ft. area of the Pa-hay-okee
water grass area we studied, a 15 egg-cluster sample size, we calculated
the average number of eggs per stem was 23. The color and hatch
time of each egg can vary differently. We noted that the eggs closest
to time of hatching are more of an ivory or pinkish color than the
ones that were laid earlier. Hatched
eggs were found on less green, or brown stalks, with the bright
white egg cases on fresh green stems. Inside the eggs of the less
developed eggs, the amniotic fluid is a transparent yellow, with
a yolk that can be opaque yellow to pink. The eggs that were next
to egg cases that had hatched contained small snails, complete with
a perfectly formed shell, and a small mollusk inside. These baby
snails were approx. 2 Ð3 mm in size.
Adult snails were hard to find, instead, we found many shells
of what used to be the snails. Snails are the main food source
of Snail Kites and Limpkins, as well as other mammals that can
be found in the marsh. Still, the immature snails that we did
find (about half an inch) were all found in the water of the marsh.
- Sources:
National Audubon Society: Field Guide to Florida. Peter Alden, Rich
Cech, Gil Nelson. Chanticleer Press, Inc: Alfred A. Knopf, New York.
1998 pg. 213
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