This small (maximum length about 60 mm) species has an 'amygdaloid' (i.e., almond) shape and a very strong hinge. It is not markedly winged posteriorly, but the posterior end is pointed and ridged. The strong v-shaped cheveron beak sculpture is restricted to the umbo.
Hyridella narracanensis (Cotton & Gabriel, 1932)
Common name: Freshwater mussel
Class Bivalvia
Infraclass Heteroconchia
Cohort Palaeoheterodonta
Order Unionida
Superfamily Unionoidea
Family Hyriidae
Subfamily Hyriinae
Genus Hyridella Swainson, 1840
Original name: Propehyridella narracanensis Cotton & Gabriel, 1932. In Cotton, B. C. & Gabriel, C. J. (1932). Australian Unionidae. Proceedings of the Royal Society of Victoria 44: 155-160.
Type locality: Narracan River, Thorpdale,Gippsland,Victoria.
Synonym: Rugoshyria depressa sodalis Iredale, 1934.
The last major taxonomic revision of Australian freshwater mussels was by McMichael & Hiscock (1958).
Based on the available molecular results, Walker et al. (2014) pointed out that a reassessment of Australian hyriids is needed and one is now in progress.
Shallow burrower in sand/mud in permanent stable streams and rivers. Suspension feeder. Larvae (glochidia) are brooded in the marsupia in the gills of females and, when released, presumably become parasitic on fish gills fins where they may undergo metamorphosis before dropping to the sediment as free-living juvenile mussels.
Coastal rivers and streams in Victoria west of south Gippsland, the Millicent Coast of South Australia and the Boobyalla and Tamar rivers of northern Tasmania with the former the only known extant populations.
This species has declined in its distribution and and is listed as threatened on the IUCN Red List (Klunzinger et al. 2014). It is also under consideration for listing in Tasmania and nationally.
Atkins, L. (1979). Observations on the glochidial stage of the freshwater mussel Hyridella (Hyridella) drapeta (Iredale) (Mollusca: Pelecypoda). Marine and Freshwater Research 30: 411-416.
Beesley, P. L., Ross, G. J. B. & Wells, A., Eds. (1998). Mollusca: The Southern Synthesis. Parts A & B. Melbourne, CSIRO Publishing.
Cotton, B.C. & Gabriel, C.J. (1932). Australian Unionidae. Proceedings of the Royal Society of Victoria (ns) 44: 155-160.
Jones, H. A. & Byrne, M. (2014). Changes in the distributions of freshwater mussels (Unionoida: Hyriidae) in coastal southeastern Australia and implications for their conservation status. Aquatic Conservation: Marine and Freshwater Ecosystems 24: 203-217.
Iredale, T. (1934). The freshwater mussels of Australia. Australian Zoologist 8: 57-78 pls 3-6.
Klunzinger, M., Walker, K. F. & Jones, H. A. (2014). Hyridella narracanensis. The IUCN Red List of Threatened Species 2014: e.T189387A58526464. http://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T189387A58526464.en
Klunzinger, M. W., Jones, H.A., Humphrey, C. L., Melchior, M., Raadik, T.A., Treby, S., Chandler, L. & Sheldon, F. (2023). Comparative diversity in glochidia of Australasian freshwater mussels. Frontiers in Environmental Science 12: 1305077.
Lamprell, K. & Healy, J. (1998). Bivalves of Australia, volume 2. Leiden, Backhuys Publishers.
McMichael, D. F. & Hiscock, I. D. (1958). A monograph of the freshwater mussels (Mollusca: Pelecypoda) of the Australian region. Australian Journal of Marine and Freshwater Research 9: 372-508 + 319 plates.
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.
Smith, B. J. (2005). Significant range extension for the freshwater mussel Hyridella (Hyridella) narracanensis in Tasmania. The Tasmanian Naturalist 127: 49-53.
Smith, B. J. & Kershaw, R. C. (1979). Field guide to the non-marine Molluscs of South-eastern Australia. Canberra, A.N.U. Press.
Smith, B. J. & Kershaw, R. C. (1981). Tasmanian Land and Freshwater Molluscs. Hobart, University of Tasmania.
Treby, S. (2016) Building mussels: Determining causes of relative abundance in two sympatric freshwater mussels (Bivalvia, Hyriidae, Hyridella) in southeastern Australia. BSc (Hons) Thesis, La Trobe University, Victoria.
Walker, K. F. (1981). The distribution of freshwater mussels (Mollusca: Pelecypoda) in the Australian zoogeographic region. Pp. 1233-1249 in A. Keast. Ecological Biogeography of Australia. The Hague, Dr W. Junk.
Walker, K. F., Jones, H. A. & Klunzinger, M. W. (2014). Bivalves in a bottleneck: taxonomy, phylogeography and conservation of freshwater mussels (Bivalvia: Unionoida) in Australasia. Hydrobiologia 735:61–79.
