Cape rock crab

Sea life: Crabs

Fish identification books for Cape Town and Southern Africa as a whole are filled with exotic species of crabs, many of which are supposed to be found in the Cape. Until recently, however I thought that the only kind of crab I would ever see in Cape Town would be the fairly common Cape rock crabs.  They have similar colouring to West Coast rock lobster, and are often found in similar locations. I’ve had the good fortune of swimming through some kelp (which these crabs like) and having one land on my head and crawl over my face. Not knowing what it was, I got quite a fright!

Cape rock crab
Cape rock crab - unusual to see them on the sand

In the last few weeks, however, we have had a total crab bonanza, mainly at Long Beach. Part of the reason is that we have been swimming very carefully over the sand, north of the very well-travelled pipeline and smaller wrecks. There we have found some fascinating new friends.

Embracing button crabs in the sand
Embracing button crabs in the sand

These two button crabs seem to be in a rather coercive relationship. I found them during the day, but apparently they are more commonly spotted at night. They look like futuristic robots, if you ask me!

Three spot swimming crab
Three spot swimming crab

Three spot swimming crabs have mournful faces on their shells, and modified back legs with paddles instead of feet. They are very feisty and will often stand their ground when encountered in the shallows. We often see a large female accompanied by her tiny male partner.

Feisty three spot swimming crab
Feisty three spot swimming crab

There are also thousands of beautiful little crown crabs all over the sand at Long Beach. They are so well camouflaged that unless you keep still and look closely, most of the time you swim right over them.

Crown crabs on the sand
Crown crabs on the sand

On the deeper reefs, where sea fans are found, you can spot sponge crabs clinging onto the fronds of the sea fans. We found this guy at Boat Rock in False Bay. Often all you can see is the little claws sticking out of the sponge, holding onto the reef.

Sponge crab on coral
Sponge crab on coral

There are many crab species that are only found in the Atlantic. As soon as Tony has a warmer wetsuit, we will be able to explore that side of the peninsula more often, and hopefully report back with pictures of sumo crabs and the like!

Of course, there are also the hermit crabs, the soft-bodied crabs that live in borrowed shells – but they are the subject of another post.

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Clare

Lapsed mathematician, creator of order, formulator of hypotheses. Lover of the ocean, being outdoors, the bush, reading, photography, travelling (especially in Africa) and road trips.

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