by Bill Barker
Most people know something about octopuses and may have seen them in rock pools. Many would have seen cuttlefish ‘bones’ on the beach. Others will be familiar with squid, which we eat as ‘calamari’. But how many people know that these are all members of the same group of animals, called ‘cephalopods’ or ‘head-foot’ animals? And how many know that they are actually more closely related to molluscs such as oysters, sea shells, slugs and snails than they are to fish or other marine creatures?
Most of the cephalopods prefer a nocturnal lifestyle, but divers and snorkelers often encounter cuttlefish during the day, usually hanging out under a rock ledge. I have even seen them from the shore at Eden harbour. These critters always convey a sense of being quite smart. They look at you out of their curiously shaped eyes as if they know who you are and what you are doing there. Many of them are inquisitive, and will even extend their tentacles to check out what you feel like – or maybe what you taste like.
Octopus are a bit more wary, perhaps understandably so, as so many of them have been taken for bait in the past. But the rock shelf rambler occasionally has a meaningful interface with octopus. Sometimes you can encourage them to extend their tentacles and shake hands. They are also among the clever guys of the snail tribe and hang out in a hole with an entrance decorated with shells and other remains of previous meals. Just watch out for the small Blue Ringed Octopus if you are exploring a rock shelf. Never touch them and never put your hands in holes. A bite from this octopus can be deadly.
Squid are great little characters. Unlike octopus or cuttlefish, who are generally solitary and spend their time on or near the bottom, squid congregate in small schools and are animals of the open water. They look like streamlined silver space craft and are just as happy to move backwards as forwards, using the jet propulsion system that is common to all the animals in this group. Snorkelers see them from time to time. They often hover in a row, looking for all the world like a squadron of helicopters.
What really makes the cephalopods special is the amazing capacity of many of them for camouflage. Not only can they change their colour in an instant to match their surroundings, but they can also change the texture of their skin so that it looks like weed or rock or whatever they are close to. A highlight is seeing cuttlefish going through their mating displays. When two males are competing for the attention of a desirable female, they engage in a kind of ‘Dancing with the Stars’ competition in which they flare their tentacles and flash all their colours like a fireworks display.
End