Darling River Snail

River Snail against a 1 cm scale

Scientific name

Notopala sublineata

Status in NSW

Critically endangered.


The Darling River Snail is a freshwater snail with a round shell that ends in a conical spire. The outer shell is generally dark green in colour but may also be greenish brown or dark brown. The body is similar to other snails, but the Darling River Snail has a prominent snout and short eye stalks on the outside of the tentacles.

Species similar in appearance

The Darling River Snail can be confused with various other freshwater snail species, particularly Notopala kingi suprafasciata, Notopala hanleyi and Notopala alisoni. Prior to recent genetic and morphological analyses, the Darling River Snail and three other species of freshwater snails were considered to be subspecies.

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.


The Darling River Snail Notopala sublineata was once common and widely distributed in the Darling River and its tributaries. The species is now restricted to a few populations in irrigation pipes near Bourke, Brewarrina and Walgett.


The species once occurred in flowing rivers throughout the Murray-Darling system, along the banks attached to logs and rocks or crawling in the mud. 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.

Why is the Darling River Snail threatened?

  • Altered flow regimes (due to weirs and dams) have impacted food sources. The Darling River Snail is not able to thrive on low nutrient content provided by algae that grows in reduced flow conditions
  • Habitat degradation and predation by the introduced Common Carp
  • Deliberate removal (using flushing chemicals) from habitats where it may still survive such as town water supply pipelines on the Darling River
  • Removal of large woody debris from rivers results in direct habitat loss for the species

More information

*note: prior to the species’ status revision in 2016, the Darling River Snail was referred to as ‘River Snail’.