Freshwater mussels should not be confused with basket shells, another common bivalve which inhabits coastal rivers. Basket shells are small and triangular, reaching a maximum size of about 15 mm. The external shell of basket shells is usually orange while the internal surface has a purplish tinge.
MUSSELp is a comprehensive online database that documents specimen collections from major museums around the world. You can use the database, together with the following information, to identify mussels in New South Wales.
Freshwater mussels in New South Wales
Hyridella australis
Distribution in New South Wales: All streams. Most common in lower reaches
Microhabitat: Areas of still-slow current often in soft sediment. Found in alcoves near streambanks and behind logs, undercut banks, and impoundments behind weirs
Appearance: Angular, glossy-black, oblong-shaped shell. Heavy V-shaped sculpturing on beaks of small shells. Maximum shell length 90 mm.
Hyridella depressa
Distribution in New South Wales: All streams except the Hunter and Shoalhaven rivers
Microhabitat: Slow-moderate currents in sand or gravel of glides and pools
Appearance: Elongated dark brown shell. Fine beak sculpture on small shells. Maximum shell length 70 mm.
Hyridella drapeta
Distribution in New South Wales: Absent or rare in the Hawkesbury-Nepean River and south of the Shoalhaven River
Microhabitat: Slow-moderate currents in sand or gravel of glides and pools
Appearance: Oval with smoothly curved outline, brown to slate-grey, never glossy. Fine beak sculpture on small shells. Maximum shell length 90 mm.
Hyridella narracanensis
Distribution in New South Wales: Upper reaches of Genoa River
Microhabitat: Moderate currents, often buried in sand or gravel. Small, shallow permanently flowing streams with intact riparian vegetation
Appearance: Almond-shaped, small shell, olive-purple brown. Heavy beak sculpture on small shells. Maximum shell length 60 mm.
Cucumerunio novaehollandiae
Distribution in New South Wales: North from the Hunter River
Microhabitat: Moderate-strong currents, often in boulder-stabilised habitats on outer bends; pools at the base of riffles and cascades
Appearance: Large, elongated, brown-black shell. Tear-shaped nodules on posterior surface of shell. Maximum shell length 200 mm.
Alathyria pertexta
Distribution in New South Wales: Richmond River upstream of Coraki
Microhabitat: Ranges from still waters to fast-flowing runs; pools and impoundments
Appearance: Heavy, elongated-oval shell, brown-black. Beak sculpture absent. Maximum shell length 160 mm.
Alathyria profuga
Distribution in New South Wales: Manning, Karuah, Hunter and Shoalhaven rivers
Microhabitat: Slow-moderate current regimes
Appearance: Solid, oval shell, brown to grey-green. Beak sculpture absent. Maximum shell length 120 mm.
Velesunio ambiguus
Distribution in New South Wales: Patchy distribution: Richmond, Clarence, Upper Macleay (Apsley River), Hawkesbury-Nepean rivers; western creeks of Shoalhaven River; Snowy River
Microhabitat: Still water or slow current areas in pools, farm dams, impoundments, lower reaches of rivers. Inhabits temporary creeks; broad environmental tolerance
Appearance: Oval, occasionally globose, light shell, yellow to dark brown. Beak sculpture absent. Maximum shell length 100 mm.
Protection of native animals
All native birds, reptiles, amphibians and mammals, but not including dingoes, are protected in New South Wales by the Biodiversity Conservation Act 2016.