We have not seen saddle shaped keyhole limpets (there are other kinds) too often. The one below I saw on a dive at Long Beach, and captured it on video (this is a still from that piece of film). They are strange looking – instead of their shell protecting their soft bodies, when they are threatened their mantle actually expands to cover the shell. There are theories that they have toxic flesh that deters predators.
An exhalant siphon extends from the hole in the top of their shells, and the front of their bodies is quite decorative with frilly extended sections that look like seaweed. Clare found the one at Long Beach too, and we took ages to figure out what it was (she initially thought it might be some kind of flatworm). It’s a keyhole limpet, however, curled up with the shell completely hidden.
This last picture, however, gave it away: the little horns, and the frilly edging of its mantle indicate that it’s a keyhole limpet. It’s also the same colour as the saddle shaped keyhole limpet depicted in Two Oceans. There seems to be some variation of colour in these creatures. Both Two Oceans and Marine Animals of the Cape Peninsula mention that juveniles are pink striped.