Neverita didyma

Neverita didyma, common name the bladder moon snail or moon shell, is a species of predatory sea snail, a marine gastropod mollusc in the family Naticidae, the moon snails.^[1] Like all naticids, this species is a carnivore and a predator.

Egg mass

Neverita didyma
A live and active individual of Neverita didyma, viewed from above
Five views of a shell of Neverita didyma
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Littorinimorpha
Family:	Naticidae
Genus:	Neverita
Species:	N. didyma
Binomial name
Neverita didyma (Röding, 1798)
Synonyms[1]
Albula didyma Röding, 1798 Glossaulax didyma (Röding, 1798) Natica ampla Iwakawa, 1900 Natica chemnitzii Récluz in Chenu, 1843 (doubtful synonym) Natica didyma (Röding, 1798) Natica glaucina Lamarck, J.B.P.A. de, 1822 Natica lamarckiana Reeve, L.A., 1855 Natica petiveriana Récluz, C. in Chenu, J.C., 1843 Natica problematica Reeve, L.A., 1855 Natica robusta Dunker, R.W., 1860 Neverita bicolor Philippi, 1849 Neverita didyma (Röding, 1798) Polinices didyma (Röding, 1798) Polinices ephebus Hedley, 1915 Polinices papyracea Busch, von dem in Philippi, R.A., 1845 Polinices (Glossaulax) aulacoglossa Pilsbry, H.A. & E.G. Vanatta, 1908, "1909" Polinices (Glossaulax) ephebus Hedley, C., 1915

Subspecies

• Neverita didyma ampla (Philippi, 1849)
• Neverita didyma hayashii (Azuma, 1961)
• Neverita didyma hosoyai (Kira, 1959)

Description

The size of an adult shell of this species varies between 20 mm and 90 mm. The shell is smooth, glossy and thick. The spiral tip isn't sticking out which is why the shell looks like a ball. The shell is always plain white sometimes with pearly pastel shades with a narrow white spiral at the spire sometimes with irregular blotches of colors. The underside of the shell includes a brown blotch with a small depression. The operculum is smooth and it's made out of a thin horn-like material that's yellow. The snail has tentacles which has opaque white bands on them.

Common misidentifications

The snail is mistaken for Polinices mammatus, the bosom moon snail that has a teardrop shaped shell and has an underside which is completely white with a bump instead of a depression. The Ball moon snail is less shy and doesn't retract immediately into its shell than the Bosom moon snail.^[2]

Eytomology

The snail gets its "moon" part of the name because its aperture is shaped like a crescent moon. The "didyma" part of the name either means "testicles" or "twins". The "ball" part of the name is because the overall shape of the shell is almost shaped like a ball.

Distribution

This marine species is found in the Yellow Sea or off the coast of the Madagascar, Mozambique, South Africa of the Indian Ocean and Australia.^[3]

Habitat

The snail is commonly seen in sandy and muddy shores usually at night or a cool day. The snail is usually ploughing through sand for hunting near beaches with seagrass. It is often found hunting for button snails. Its predator is Argyrops spinifer.^[4]

Culinary use

Golbaengi-muchim (moon snail salad)

In Korean cuisine the snails are used in a dish called golbaengi-muchim (moon snail salad). It is usually collected using fishing nets at depths of 2-10 m.^[5]