Ridged neptunes (Neptunea lyrata) are one of Kachemak Bay’s largest deepwater snails. While only a keen-eyed tidepooler might find one of these predatory snails exposed by an ebbing spring tide, they are relatively common in our region.
Preying on barnacles, bivalves and polychaete worms or scavenging on decomposing marine animals, ridged neptunes inhabit sand or mud substrates in fairly deep water. They are capable of extending their long, tubular proboscis — a tubular feeding organ — deep into sand or mud to feed on buried animals.
Female ridged neptunes deposit clusters of egg capsules during the spring on hard surfaces (or another snail’s egg mass); each yellow, flattened capsule contains about 2,400 eggs, of which only one to four develop and hatch out as juvenile crawling snails 10 to 13 months later. The remaining eggs serve as nurse eggs, eaten by those young that survive to hatch. Broken off from their sea floor bases by strong currents or storms, these egg masses commonly wash ashore along the Homer Spit or at Bishop’s Beach looking a bit like worn corncobs.
To learn more about the Kachemak Bay Research Reserve, please visit www.kbayrr.org.
Carmen Field is a biologist, naturalist and marine science educator at the Kachemak Bay Research Reserve.
These thick-shelled gastropods live from Arctic Alaska south to central California, with a subspecies also found along the north Atlantic coast. Their stout, tan or reddish shell can measure up to 7 inches (18 centimeters) long and exhibits five or six whorls decorated by raised spiral ribs (or cords) alternating with a few small, finer cords. The shell’s opening (or aperture), which is broadly ovate with a white interior and flared lip, spans nearly half the length of the shell. The snail itself is pale gray with black speckling. Discovering a moving neptune shell doesn’t necessarily mean the snail is alive — empty shells are frequently borrowed by large hermit crabs.
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