Smeagol hilaris

X-ray image of three marine slugs

Scientific name

Smeagol hilaris

Status in NSW

Critically endangered.


Smeagol hilaris is a pulmonate slug and is one of five species in the genus Smeagol. Pulmonate slugs have developed lungs instead of gills and can breathe air. They are a translucent white in colour resembling a fly maggot, with some of the internal organs visible through the exterior surface.


Most specimens found have been 5 – 6 mm long.

Many Smeagol under a rock (Photo: M. Nimbs)


Smeagol hilaris has only been collected from a small isolated location at Merry Beach, south of Ulladulla, New South Wales, Australia.


Smeagol hilaris lives in gravel and cobble filled rocky crevices at Merry Beach. Little is known about their ecology or reproductive biology

Smeagol hilaris habitat

Why is Smeagol hilaris threatened?

  • Habitat damage and/or alteration due to development and urbanisation in nearby areas
  • Storm water run-off from adjacent roads and built environments
  • Increased human impacts on the beach and surrounding habitat
  • Pesticides
  • Climate change
  • Invasive species

A close-up of Smeagol hilaris (Photo: T. Davis)

More information