Matt Nimbs

PhD project title: Taxonomy and Systematics of the Australian Aplysiidae

Principal supervisor: Professor Steve Smith

Co-supervisor: Associate Professor Kirsten Benkendorff and Dr Nerida Wilson (Western Australian Museum)

Research summary

The Aplysiidae is a small family of heterobranch sea slugs that consume marine plants  are commonly known as ‘sea hares’.  There are 23 nominal species of sea hare in Australian waters, however the enumeration of the aplysiids in this region suffers considerable insecurity through a history of uncritical taxonomic descriptions. For example, the original description of Aplysia sydneyensis was based solely on its vestigial internal shell, whereas other widely-distributed taxa were described using specimens sourced from a single location, and some may represent a cryptic species complex but are presently recognised as mere colour morphs. These taxonomic problems make identification of specimens  where regional variation may exist  difficult.  Thus there is scope for taxonomic rationalisation, particularly with the advantage of modern molecular analysis.

More uncertainty stems from an assumed circumglobal distribution for some taxa. Only two species, Aplysia dactylomela  and A. parvula , have been genetically analysed so far and both were both found to comprise separate species in the Atlantic and Indo-Pacific Oceans. Furthermore, sea hares exhibit high ontogenetic variation; there is wide-ranging intraspecific variation in some species (particularly body colour); and, some taxa exhibit high intraspecific plasticity in body shape.

Using integrated molecular and morphological data this project seeks to resolve the current taxonomic problems in the Australian aplysiid fauna through a combination of new species descriptions, synonymies and a family phylogeny.


  • 2017 Australian Biological Resources Study NTRGP top up grant
  • 2017 Malacological Society of Australasia, small project grant for: Continental divide: is the giant sea hare Aplysia gigantea from Western Australia and Aplysia extraordinaria from eastern Australia the same species?
  • 2016 SCU Professor Peter Baverstock Research Path Honours Scholarship
  • 2016 Joyce W. Vickery Research Fund small research grant