Eastern Mudsnail
Ilyanassa obsoleta (Say, 1822)
Family Nassariidae
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Eastern Mudsnails are rare on S. Hutchinson Island beach and usually very wave-worn.
Enlarged- this mudsnail is only .6" long (S. Hutchinson Island- January 2021)
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Ilyanassa obsoleta
Eastern Mudsnail
Characteristics:
The eastern mud snail is a benthic gastropod with a black or dark brown conical shell. Their size ranges from 1.5-3cm in length. That's about the size of a push pin!
Picture
Picture
Habitat: estuarine; the mudflats in the intertidal and shallow subtidal zones; brackish water habitats
Feeding habits: I. obsoleta are detritus eaters, meaning they eat organic debris that is formed from the decay of biotic material such as fish, algae, and crustacean remains.
I. obsoleta is able to eat sediment wholly! Its digestive tract breaks down organic matter leaving almost completely inorganic waste.
Life cycle:
Mud snail eggs hatch into larvae after 10 days. Larvae, immature snails, are free swimming and move with water currents. Larvae feed on phytoplankton 20-30 days before settling down on a substrate (hard surface). They remain dormant during the winter and do not grow until the summertime. These mud snails live for approximately 5 years.
Picture
Ilyanassa obsoleta with egg cases attached to Gracilaria.
PictureI. obsoleta mud snail eggs
Did you know... I. obsoleta are commonly used to keep aquarium cleans!
Scientific Classification:
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Family: Nassariidae
Genus: Ilyanassa
Species: I. obsoleta