Order

Cycloneritida

  Class

Gastropoda

  No. of Genera in Ref.

  No. of Species in Ref.

  Environment

Fresh : No | Brackish : No | Marine : Yes

  Aquarium

  First Fossil Record

     

  Remark

Shell globose, often thick and solid, with a moderately low spire and a very large, rounded body whorl (Ref. 128042). No umbilicus. Outer surface smooth, or costulate to spinose. Aperture semicircular, without a siphonal canal. Inner and outer lip often toothed. Columella forming a flat calloused inner lip, protruding as a septum that narrows the aperture. Columellar shield smooth, ridged or pustulose. Interior of shell porcelaneous, with the inner walls of the spire whorls resorbed in adult stages. Operculum semicircular, calcified, with a few spiral coils and a projecting peg on its inner edge. Head large, with a broad, short and commonly indented snout. Cephalic tentacles slender, with eyes on prominent stalks at their outer bases. Foot oblong, wide in front and attenuated behind. Mantle cavity deep, with a single long, triangular gill. Along shorelines in warm temperate to tropical, marine, brackish, or even fresh-water habitats. Marine species often live quite high in the intertidal zone, and are exposed to the air and sun for long periods. The tightly fitting operculum prevents dessication and, in some species, the surface of the mantle cavity acts as a primitive lung. Herbivorous animals, grazing by night at low tide on fine algae and detritus covering the bottoms where they live. Sometimes forming very large colonies. Sexes separate, fertilization internal. Eggs laid in capsules, attached to the rocks or to the shells of nerites. Nerites are commonly collected by coastal people, for human consumption and for shellcraft (Ref. 349).

  Etymology

  Division

  Reproductive guild

  Typical activity level

  Main Ref.

  Coordinator