< Previous family introduction

Next family introduction >

Family Naticidae

Sand or Moon Snails




The sand snails are a relatively small family with about 200 living species, cosmopolitan in distribution. They are common inhabitants of intertidal sand and mud flats, where they plough through the sand or mud, on or just below the surface, leaving a broad trail behind them. They are carnivorous, feeding mainly on bivalves; they drill a small hole by radular action assisted by acid secretions and suck the tissues out of the prey.

The family is well represented in NSW with 25 species recorded. Five large species occur in estuaries and on exposed beach flats around Sydney, with Conuber conicum and Conuber sordidus being the most common. A few representatives of the tropical Indo-West Pacific fauna intrude into the north of the state, occasionally reaching Sydney. The third component of the local fauna is a group of deep-water species, some of which are common but rarely seen in collections; they are mainly less than a centimetre in size, and have eastern or southern Australian distributions.

Family References:

  • Cernohorsky, W.O. 1971. The family Naticidae in the Fiji Is. Records of the Auckland Institute & Museum 8:169-208.

  • Kilburn, R.N. 1976. A revision of the Naticidae of southern Africa and Mocambique (Mollusca). Annals of the Natal Museum 22(3):829-884.

  • Kabat, Alan R. 1991. The classification of the Naticidae (Mollusca: Gastropoda): review and analysis of the supraspecific taxa. Bulletin of the Museum of Comparative Zoology 152(7): 417-449.


In addition to those illustrated, the following species occur in NSW.

Tropical Indo-West Pacific species that reach into NSW, but are of uncommon to rare occurrence here:

  • Natica alapapilionis (Roding, 1798). Indo-West Pacific to Woolgoolga, NSW.

  • Natica fasciata (Roding, 1798). Indo-West Pacific, to Solitary Islands, NSW.

  • Natica onca Roding, 1798. Indo-West Pacific to Woolgoolga, NSW.

  • Natica pseustes Watson, 1881. Indo-West Pacific to Sydney, NSW.

  • Mammilla melanostomus (Gmelin, 1791). Indo-West Pacific to Sydney, NSW.0

  • Mammilla fibrosa (Eydoux & Souleyet, 1852). Indo-West Pacific to Broulee, NSW.

One species is known only from the holotype , probably subfossil, dredged from Sydney Harbour:

  • Gennaeosinum intercisum Iredale, 1931. Length of holotype 13 mm.

Identification Notes:

Two useful characters for the identification of species in this family are the columellar callus and the operculum. The shape of the callus, and the extent to which it covers the umbilicus, assist in separating species, although there is some ontogenetic variation of this character within a given species. The operculum may be calcareous or corneous, a characteristic use for definition of the genera.