Key to Australian Freshwater and Terrestrial Invertebrates

Phylum Mollusca
Class Gastropoda
Informal group Architaenioglossa
Superfamily Cyclophoroidea

Common name: land snails

Overview

Cyclophoroidea are medium-sized terrestrial snails that have lost the ctenidium (comb-like respiratory apparatus or gill) but have the mantle modified into a vascularised pulmonary cavity (a lung). The aperture is small and circular and the operculum is circular to oval and is typically composed of horny material with some calcareous elements. The head bears a pair of eyes on slightly raised peduncles that are situated at the base of the only pair of cephalic (head) tentacles. Shells are solid and ovoid, either globose or slender, and are often strongly sculptured with a glossy texture and the shell coiling is often uneven and irregular.

Distribution and diversity

Cyclophoroidea consists of nine families that occur in moist tropical and sub-tropical forests throughout south-eastern Asia, India, Madagascar and Africa, with species reaching islands of the western Pacific, including Australia and New Zealand. In Australia, 39 species from 10 genera in four families are found in the wet forest areas of eastern Queensland and New South Wales and Lord Howe and Norfolk Islands.

Life cycle

Life histories of most species are unstudied. Species are typically dioecious (sexes are separate) and are oviparous or ovoviviparous. Egg laying species may deposit eggs in an egg mass, each egg having a calcareous shell.

Feeding

Feeding habitats of Cyclophoroidea are largely unknown but most are herbivores and/or detriviores grazing on a range of living and dead plant material.

Ecology

Cyclophoroidea are typically found in wet conditions on the underside of leaves of trees, in the understory, under rocks and amongst mosses and leaf litter, with some species associated with limestone outcrops. They do not regulate water loss very well and as such, are only active in periods of very high humidity such as at dusk, dawn, during the night or during light rainfall. To prevent moisture loss when humidity is low, cyclophoroids remain inside their shell, with the operculum tightly closed.