Austropeplea Cotton, 1942

Disclaimer

This genus is in need of revision, and the species concepts we have used have not been rigorously tested. There are few morphological characters that allow separation between species and they are difficult to separate based on shell characters alone. This situation needs to be resolved by additional molecular and morphological studies, involving comprehensive sampling.

Diagnostic features

The shell is small to medium, oval, and the columella is rather indistinctly twisted. The spire is low to moderately raised and there is usually a well-defined parietal area.

The animal has a reflected mantle border and the cephalic tentacles are short and triangular. The prostate gland has a single large internal fold, and the radula has tricuspid inner lateral and multicuspid outer lateral teeth.

Classification

Austropeplea Cotton, 1942

Class Gastropoda

Infraclass Heterobranchia

Megaorder Hygrophila

Order Lymnaeida

Superfamily Lymnoidea

Family Lymnaeidae

Subfamily Amphipepleinae

Genus Austropeplea Cotton, 1942

Type species: Limnea papyracea Tate, 1879 (=Austropeplea (Austropeplea) papyracea (Tate, 1879)

Original reference: Cotton,B.C.1942. Some Australian freshwater Gastropoda. Transactions of the Royal Society of South Australia. 66: 75-82.

Type locality: Penola, South Australia

Synonyms: Simlimnaea Iredale, 1943; Glacilimnaea Iredale, 1943.

Two subgenera are recognised:

Austropeplea (Austropeplea) Cotton, 1942

Austropeplea (Kutikina) Ponder & Waterhouse, 1997

State of taxonomy

Until recently, a large number of available names for these Australian lymnaeids (e.g., Iredale 1943, 1944) were lumped as Austropeplea tomentosa (e.g., Boray & McMichael, 1961), a name based on a New Zealand species. Recent studies have shown that A. tomentosa is very different from the Australian taxa (Puslednik et al. 2009). However, unlike Puslednik et al. (2009), we tentatively recognise three species in SE Australia, based on differences in anatomy and molecules.

This genus is in need of revision and the species concepts we have used have not been rigorously tested. There are no clear-cut shell characters that allow separation. The current situation is clearly far from satisfactory and can only be resolved by additional molecular and morphological studies involving dense sampling.

Biology and ecology

Members of the typical subgenus are found amongst water vegetation in dams, ponds, billabongs, rivers, streams, water-logged pasture, springs and swamps. They are semi-amphibious - often found out of the water along the banks on damp mud. Common. They feed on algae and detritus. The egg mass a crescent-shaped jelly strip containing many small eggs. Development is direct.

The only species in the subgenus Kutikina is fully aquatic, occurring below the water line, attached to smooth or algal and liverwort-covered vertical or near vertical limestone rocks, boulders or rock faces on the edges of the river where there is a fast flow.                                 

Distribution

South-eastern Australia, including Tasmania.

Notes

This genus differs from the other native lymnaeid genus Bullastra in its much smaller size and less inflated shell. It differs from the introduced lymnaeid genera Radix, Lymnaea, Pseudosuccinea and Orientogalba in having a less raised spire and, in the case of Pseudosuccinea, lacking spiral sculpture.

Species in this genus are vectors of the liver fluke parasite (Fasciola hepatica) that infects sheep, cattle and occasionally humans.

Austropeplea belongs to a group of Asian and Australasian lymnaeids (and including Radix) having 16 pairs of chromosomes and having a single large fold in the prostate gland.

Further reading

Beesley, P. L., Ross, G. J. B. & Wells, A., Eds. (1998). Mollusca: The Southern Synthesis. Parts A & B. Melbourne, CSIRO Publishing.

Boray, J. C. (1964). Studies on the ecology of Lymnaea tomentosa, the intermediate host of Fasciola hepatica. 1. History, geographical distribution, and environment. Australian Journal of Zoology 12: 217-230.

Boray, J. C. (1966). Studies on the relative susceptability of some lymnaeids to infection with Fasciola hepatica and F. gigantica and on the adaptation of Fasciola spp. Annals of Tropical Medicine and Parasitology 60: 114-123.

Boray, J. C. (1968). Host-parasite relationship between lymnaeid snails and Fasciola hepatica. Proceedings of the 3rd International Conference of the World Association for the Advancement of Veterinary Parasitology, Lyon, ,France. Veterinary Medical Review, Leverkusen.

Boray, J. C. (1969). Experimental fascioliasis in Australia. Advances in Parasitology 7: 95-210.

Boray, J. C. & McMichael, D. F. (1961). The identity of the Australian lymnaeid snail host of Fasciola hepatica L. and its response to environment. Australian Journal of Marine and Freshwater Research 12: 150-163.

Bradley, B. (1926). Note on the presence of Cercaria pigmentisa in Limnaea brazieri bred in an aquarium to which sheep fluke eggs has been added. The Medical Journal of Australia 1926: 3-7.

Campbell, N. J. (1977). Identifying liver fluke snails. Agricultural Gazette of New South Wales 88: 24-26.

Correa, A. C., Escobar, J. S., Durand, P., Renaud, F., David, P., Jarne, P., Pointier, J.-P. & Hurtrez-Boussès, S. (2010). Bridging gaps in the molecular phylogeny of the Lymnaeidae (Gastropoda: Pulmonata), vectors of Fascioliasis. BMC Evolutionary Biology 10 381(1-12)..

Hubendick, B. (1951). Recent Lymnaeidae: their variation, morphology, taxonomy, nomenclature and distribution. Kongliga Svenska Vetenskapsakademiens Handlingar 3: 1-223.

Inaba, A. (1969). Cytotaxonomic studies of lymnaeid snails. Malacologia 7: 143-168.

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

Iredale, T. (1944). Guide to the freshwater shells of New South Wales. Part 2. Australian Naturalist 11: 113–127.

Puslednik, L., Ponder, W. F., Dowton, M. & Davis, A. R. (2009). Examining the phylogeny of the Australasian Lymnaeidae (Heterobranchia: Pulmonata: Gastropoda) using mitochondrial, nuclear and morphological markers. Molecular Phylogenetics and Evolution 52: 643-659.

Rathinasamy, V., Hosking, C., Tran, L., Kelley, J., Williamson, G., Swan, J., Elliott, T., Rawlin, G., Beddoe, T. & Spithill, T. W. (2018). Development of a multiplex quantitative PCR assay for detection and quantification of DNA from Fasciola hepatica and the intermediate snail host, Austropeplea tomentosa, in water samples. Veterinary Parasitology 259: 17-24.

Remigio, E. (2002). Molecular phylogenetic relationships in the aquatic snail genus Lymnaea, the intermediate host of the causative agent of fascioliasis: insights from broader taxon sampling.Parasitology Research 88: 687-696.

Vinarski, M. V., Clewing, C. & Albrecht, C. (2019). Lymnaeidae Rafinesque, 1815. Pp. 158-162 in C. Lydeard & Cummings, K. S. Freshwater Mollusks of the World: a Distribution Atlas. Baltimore, John Hopkins University Press.