Sea Hare

With their bunny-like head tentacles and charismatic expressions, these marvelous molluscs are always sure to bring a smile to your rock pool adventures.
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The sea hare (Aplysia punctata) gets its common name from the two tentacles on its head, which resemble the ears of a hare. In fact these are specialized tentacles called rhinophores. These sensory organs allow the sea hare to smell or taste its surroundings.
Sea hares found in rockpools are commonly up to 7cm in length, although those living in subtidal areas may reach up to 20cm! These charming critters are in fact marine snails and possess an internal shell, unlike most sea slugs. This may be seen through an opening in their back (mantle), and appears peach coloured. Their bodies vary in colour and often are marked with dark patterning.



The sea hare is mainly found on the lower shore, although their abundance is variable both seasonally and annually.
Sea hares are hermaphroditic, meaning that they each have both male and female reproductive organs. However, rather than self fertilize, they mate in chains, with each individual acting as either a male or female. Keep your eyes peeled amongst the seaweed and under large rocks and you may be lucky enough to spot one of these chains or the resultant pink threads of eggs.


The sea hare is a classic example of “you are what you eat”, with their bold and variable colour attributed to their diet. Therefore, a sea hare which appears darker, with a more purple or deep red colouration, will have been feeding primarily upon red algae such as dulse. Meanwhile sea hares which are lighter, with olive-brown and gold tones will have consumed mainly green and brown algae such as sea lettuce or kelp.

The rock pool project:

The sea hare has proved a more elusive species so far for the rock pool project, only recorded at three survey sites to date. If you find one on your next survey be sure to let us know!

Table of Contents

Rock Pool Project discoveries for this species: