Fauna
Invertebrate

Sydney Seahare

Aplysia sydneyensis

Also known as Sydney Sea Hare

Sydney seahares are soft-bodied marine molluscs that graze steadily among sheltered bays, rock pools, and coastal reefs across temperate Australia. They possess wing-like parapodial flaps along their backs and paired head tentacles resembling rabbit ears, which serve as sensitive chemo-receptors to detect edible macroalgae. When startled or roughly disturbed, they can expel a cloud of vibrant purple-red ink derived from pigments sequestered from the red seaweed in their diet.

MarineIntertidalHerbivore
Sydney Seahare reference
(c) libby hepburn, some rights reserved (CC BY), uploaded by libby hepburn · cc-by
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Key facts
Diet & preyRed algae, Sea lettuce (Ulva lactuca), Green algae
Predators
  • Octopuses
  • Predatory sea snails
  • Crabs
ThreatsCoastal water pollution, sedimentation, and habitat destruction from shoreline development
HabitatsIntertidal rock platforms, estuaries, seagrass meadows, and shallow subtidal reefs
Life spanAbout 1 year
Classification
  1. OrderAplysiida
  2. FamilyAplysiidae
  3. GenusAplysia
  4. SpeciesAplysia sydneyensis
Range & activity
Range data is not available yet.
Safe observation
Interaction riskHigh
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is high
Safe to observe at a normal distance.
Responsible observation
  • Tide Pool Etiquette: Observe them submerged without lifting them from the water, as their soft bodies lack rigid skeletal support.
  • Ink Defense: Avoid poking or prodding them, which triggers an inking response that wastes valuable defensive reserves.
  • Low Tide Timing: Visit shallow intertidal shelves during spring low tides when they often feed exposed among algae beds.
Related species
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