Notopala hanleyi
Critically endangered.
Hanley’s River Snail is a freshwater snail with a round shell that ends in a conical spire. The outer shell is generally dark green but may also be greenish brown or dark brown. The body is similar to other snails but Hanley's River Snail possesses a prominent snout and short eye stalks on the outside of the tentacles.
Hanley’s River Snail can be confused with various other freshwater snail species, particularly Notopala sublineata (Darling River Snail). Prior to recent genetic and morphological analyses, Hanley’s River Snail and three other species of freshwater snails were considered to be subspecies of Notopala sublineata.
The main distinguishing feature between the Darling River Snail and Hanley's River Snail is their distribution. Hanley's River Snail is found in the Murray River catchment, including the Lachlan and Murrumbidgee Rivers, whereas the Darling River Snail is found in the Darling River catchment.
They can grow to 20-25 mm in size.
Hanley’s River Snail was once common and widespread in the Murray River catchment, including the Lachlan and Murrumbidgee Rivers. They are now virtually extinct throughout their natural range and living specimens have only been found from within irrigation pipelines in South Australia and Far South-West NSW.
The species once occurred in flowing, well-oxygenated waters throughout the Murray River catchment. Artificially introduced hard surfaces now provide habitat for the species with populations being recorded as surviving in irrigation pipelines. The pipeline environment is thought to promote microbial production and organic accumulation, which is a highly nutritious food source for the species.