Overview
Moon snails (family Naticidae) are predatory marine gastropod molluscs with mostly globular shells. They are the only family within the superfamily Naticoidea.
Classification and Diversity
- Family: Naticidae; superfamily: Naticoidea; clade: Littorinimorpha.
- Estimated 260–270 recent species; origin in late Triassic or early Jurassic.
- Recognizable by globular shells, distinct appearance, and drilling predation behavior.
Subfamilies (Bouchet & Rocroi, 2005)
- Naticinae (Guilding, 1834)
- Sininae (Woodring, 1928)
- Globisininae (Powell, 1933)
- Polinicinae (Gray, 1847)
Distribution and Habitat
- Worldwide distribution; highest species and genus diversity in tropical regions.
- Also plentiful in temperate, Arctic, and Antarctic waters.
- Live on sandy substrates from intertidal zones to thousands of meters deep.
- Often plough through sand hunting, leaving characteristic countersunk bore-holes.
Feeding and Predation
- Predators mainly of bivalves; also attack scaphopods and other gastropods, including conspecifics.
- Conuber sordidum drills and preys on soldier crabs Mictyris longicarpus using similar hunting behavior.
- Predation sequence: prey enveloped; shell bored with radula and acid secretion; proboscis consumes flesh.
- Bore-holes have chamfered, countersunk appearance; hole size varies by species.
Reproduction: Sand Collars
- Females lay stiff egg masses of sand and mucus called sand collars.
- Sand collars are unique to Naticidae and often wash up on sandy beaches.
- Structure: sand grains in a gelatinous matrix containing eggs in many capsules.
- Size of collar indicates size of laying female; larger species produce larger collars.
- In planktonic developers, embryos hatch as bilobed veligers; collars disintegrate after hatching.
Human Interactions
- In Korean cuisine, moon snails (golbaengi) are eaten as golbaengi-muchim (moon snail salad).
- Shells are attractive, relatively large, and popular in jewelry and ornamentation.
Traditional vs. Modern Taxonomy
- Traditional morphology-based separation into Ampullospirinae, Naticinae, Polinicinae, Sininae.
- Criteria included operculum material (calcareous vs. corneous), operculum size, and shell morphology.
- 2005 taxonomy recognizes Naticinae, Sininae, Globisininae, Polinicinae.
Selected Genera by Subfamily
| Subfamily | Representative Genera |
|---|
| Naticinae | Cochlis; Cryptonatica; Natica; Naticarius; Notocochlis; Paratectonatica; Proxiuber; Stigmaulax; Tanea; Taniella; Tasmatica; Tectonatica |
| Globisininae | Falsilunatia; Globisinum |
| Polinicinae | Amauropsis; Bulbus; Conuber; Euspira; Friginatica; Glossaulax; Hypterita; Kerguelenatica; Mammilla; Neverita; Polinices; Pseudopolinices; Sinuber; Tahunacca; Uberella |
| Sininae | Calinaticina; Eunaticina; Gennaeosinum; Payraudeautia; Sigaretotrema; Sigatica; Sinum |
| Incertae sedis (temporary) | Haliotinella; Microlinices |
| Unassigned | Amauropsina; Amauropsona; Austrocochlis; Benthobulbus; Carinacca; Cepatia; Darwinices; Laguncula; Magnatica; Maxwellinatica; Nanggulania; Pliconacca; Polinella |
| Excluded/notes | Gyrodes (Gyrodidae); Spironema (not in WoRMS) |
Synonyms (Selected)
- Acrybia → Bulbus; Albula (junior homonym) → Polinices; Aloconatica → Stigmaulax.
- Boreonatica → Cryptonatica; Catinus → Sinum; Cryptostomus → Sinum.
- Eucaryum → Polinices; Eunatica (unaccepted rank) → Natica.
- Lunaia → Natica; Lunatia → Euspira; Heliconatica → Eunaticina.
- Mamilla (misspelling) → Mammilla; Mamillaria → Polinices; Mamma → Polinices.
- Nacca → Natica; Naticina (Gray, 1847) → Eunaticina; Naticus → Naticarius.
- Naticella; Naticina (Guilding, 1834, subjective) → Polinices; Polynices (emendation) → Polinices.
- Quantonatica → Naticarius; Ruma → Mammilla; Sigaretus → Sinum; Uber → Polinices.
- Additional junior synonyms and emendations listed in source.
Key Terms & Definitions
- Radula: Ribbon-like structure with teeth used for drilling and feeding.
- Proboscis: Extendable feeding organ used to ingest prey tissues.
- Countersunk bore-hole: Chamfered, recessed hole characteristic of naticid drilling.
- Sand collar: Gelatinous sand-egg matrix egg mass unique to Naticidae.
- Veligers: Bilobed planktonic larval stage in some species.
- Operculum: Plate closing the shell opening; material varies by subfamily (calcareous or corneous).
Action Items / Next Steps
- Review Bouchet & Rocroi (2005) for detailed subfamily diagnoses.
- Compare operculum material and shell morphology when assigning genera to subfamilies.
- Use bore-hole morphology and sand collar characteristics for field identification where applicable.