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Notopala essingtonensis (Frauenfeld, 1862)

Diagnostic features

This species differs from other species of Notopala in its somewhat conical shell with dark colour bands. Similar banding is seen in N. tricincta but that is a riverine species with a shorter spire and relatively larger aperture.

Classification

Notopala essingtonensis (Frauenfeld, 1862)

Common name: Port Essington River Snail

Class Gastropoda

Subclass Caenogastropoda

Order Architaenioglossa

Superfamily Viviparioidea

Family Viviparidae

Subfamily: Bellamyinae

Genus Notopala Cotton, 1935

Original name: Vivipara essingtonensis Frauenfeld,1862. Frauenfeld, G. R. von. 1862. Zusammenstellung der Arten der Gattung Vivipara Lmk.in Kaiserlichen Sammlung. Verhandlungen der kaiserlich-königlichen Zoologisch-Botanischen Gesellschaft Wien 12(2): 1162-1170.

Type locality: Port Essington, Northern Territory.

State of taxonomy

The taxonomy used here for Viviparidae is largely based on unpublished research by W. Ponder. Several undescribed taxa are known that mainly occur in areas outside the distribution of the species recognised here.

Biology and ecology

This species is found in billabongs, coastal lagoons and temporary pools associated with drainage channels. Although the biology of this species has not been studied, its anatomy shows that it is, at least in part, a suspension feeder, using the gill for filtering food from the water like other viviparids, and that it broods its eggs in the pallial oviduct. The brooded young are released simultaneously.

Distribution

Typical N. essingtonensis is found on the Adelaide River flood plains and nearby areas, south of Darwin, Northern Territory. The type locality, “Port Essington” (on the Coburg Peninsula) is incorrect as this species is not found in that area. Similar shell forms are found in Queensland and (rarely) in New South Wales, but these may represent undescribed taxa.

Notes

Stoddart (1982) used this species name for all of the banded species of Notopala.

Banded species of Notopala occur in several parts of northern Australia and Queensland that are similar to N. essingtonensis, N. tricincta and N. kingi but are thought to be different species (W. Ponder, unpublished studies). These should be identified simply as Notopala sp.

Further reading

Cotton, B. C. (1935a). The Australian viviparous river snails. Victorian Naturalist 52: 96-99.

Cotton, B. C. (1935b). Recent Australian Viviparidae and a fossil species. Records of the South Australian Museum 5: 339-344.

Iredale, T. (1943). A basic list of the fresh water Mollusca of Australia. Australian Zoologist 10: 188-230.

Sheldon, F. & Walker, K. F. (1993). Shell variation in Australian Notopala (Gastropoda: Prosobranchia: Viviparidae). Journal of the Malacological Society of Australia 14: 59-71.

Smith, B. J. (1992). Non-marine Mollusca. Pp. i-xii, 1-408 in W. W. K. Houston. Zoological Catalogue of Australia, 8. Canberra, Australian Government Publishing Service.

Stoddart, J. A. (1982). Western Australian viviparids (Prosobranchia: Mollusca). Journal of the Malacological Society of Australia 5: 167-173.