I love the little False Bay sharks, the little cat sharks and shy sharks that are found throughout our rocky reefs and kelp forests and almost always snoozing at the end of the pipeline at Longbeach.
Pyjama sharks (Poroderma africanum) are a species of catsharks, the largest family of sharks. They are elongated, slender sharks with short whisker-like barbels and cat-like eyes: horizontally oval with elongated pupils and a nictitating membrane, that give them the name “catshark”. They grow to about a metre long and can weigh up to 8 kg. Of course, their most notable characteristics are their alternating black and grey stripes that run the length of their bodies, from snout to tail tip.
During the day, pyjama sharks spend their time hiding motionless in caves and rocky crevices or under fronds of kelp. They need to pick their hiding spots carefully – they are easy prey for opportunistic Cape fur seals and broadnose sevengill sharks. They don’t have any defences against these large predators, so when threatened they will roll themselves into a “doughnut”, protect their eyes with their tails, and wait for an opportunity to escape.
They are nocturnal hunters and their flat, cusped teeth are ideal for gripping slippery prey, like octopuses, and for crushing prey with hard shells and exoskeletons, like West Coast rock lobsters, which is a favourite of theirs in False Bay. Using the excellent grip of these teeth, pyjama sharks can perform a “death roll” similar to that of an alligator, which allows them to pry prey off of rocks, or to tear an arm off an octopus that is too large to be eaten completely.
During the peak breeding season of the Chokka Squid, the pyjama sharks switch to daytime hunting and hide motionless among squid egg strands (the stripes help to break up their outline into unrecognizable shapes, thus camouflage the shark). Since Chokka Squids are known to tear off at high speed after spawning, this behavior is putting the shark in a perfect position to ambush the distracted squids from close range.
As juveniles, the pyjama sharks are prey for a variety of species, from large fish to seals, and there are even species of snails that specialise in eating them as embryos inside their egg cases.
There is no mating season for pyjama sharks and they are able to mate whenever there is a sufficient abundance of food. Females lay two eggs at a time, and attach them in places they think are well-hidden, where they remain until they hatch about five months later.
Currently, pyjama catsharks are listed as a Least Concern species by the IUCN, unfortunately, many fishermen view small sharks, like pyjama sharks, as pests and many of them kill these sharks indiscriminately, rather than releasing them. The reality is that sharks are crucial to maintaining healthy ecosystems, so this is doubly unfortunate, as these misguided actions will actually harm the fish stocks that these fishermen depend on in the long run.
For this reason, WWF SASSI lists pyjama shark as a Red List species. Although it is not commonly sold, its addition to the Red List is a further deterrent to those who may choose to kill, rather than release these sharks.