When is a hare really a slug?

Some of the prettiest mysteries we have on the trip are the sea hares.

They’re a mystery because no one here is a sea hare expert, and Mandy can’t find any of them in the books we have (and I think they are very pretty!). So, we can’t put names to them, or work out whether perhaps they don’t yet have a name and are a new species. Now that would be very exciting!

Sea hares, or sea slugs, are related to slugs and snails, although they lost their shells a long time ago. They get the name ‘hare’ not because they are fast and good at jumping, but because like hares and rabbits they are constantly munching their way through small plants that grow on all the rocks. Some of them are really well camouflaged and look just like the rocks they are living on.

Sea hares are related to slugs and snails but they lost their shells a long time ago

Some of the sea hares are very brightly coloured – they probably protect themselves with horrible tasting chemical secretions and they are advertising this fact: ‘don’t eat me, because I taste nasty!’

Sea hares get their name because like hares and rabbits they are constantly munching on small plants

Most of the ones we have found have been the size of the palm of my hand, about 7 centimetres long, but today Mandy found an absolute whopper, the size of a rugby ball.

What a whopper: massive sea hare (or slug) with mollusc expert Mandy

Because it has no backbone and no protective shell it went all floppy while Mandy was holding it for the photo, so here’s another photo to give you a better sense of its shape. It looks like a misshaped ball.

Its head is at the right side of this photo, and you can just make out its sensory tentacles that it uses to find its way around. It moves along on a strong muscular foot, just like a common garden snail.

A closer look at the massive sea hare

And here’s the prettiest thing we’ve found – it’s a cousin of the sea hares, called a nudibranch. The gills that it breathes through are the purple feathery crown you can see near the top of the photo. I reckon it’s a real sweetie!

The sea hare’s pretty cousin: the nudibranch’s gills are the purple feathery crown you can see near the top of the photo

Dr Tom Trnski

Auckland Museum

David Aguirre

Massey University

Libby Liggins

Massey University

Phil Ross

University of Waikato

Sam McCormack

University of Waikato

Andrew Pinniket

Our Big Blue Backyard

Brady Doak

Our Big Blue Backyard

Kina Scollay

Our Big Blue Backyard

Kyle Swann

Our Big Blue Backyard

Lindsey Davidson

Our Big Blue Backyard

Ross Funnell

Our Big Blue Backyard

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Braveheart

For 21 days home for the crew is the RV Braveheart. The 39 metre long vessel has visited the Kermadecs many times before as well as other parts of the Pacific & Southern Oceans.