SASC: The Pyjama Shark (Poroderma africanum)
Catarina Abril with a pyjama catshark in Hermanus New Habour, Western Cape.
For the next installment of my blog series uncovering my life-changing month with the South African Shark Conservancy let’s take a look at one of the three endemic species we were focusing on – the pyjama shark (Poroderma africanum).
You may recognise them from their David and Goliath-esque battle with an octopus on Blue Planet II last year. This stunning shark can only be found in the waters of southern Africa and is a bottom-dwelling species that inhabits rocky reefs and kelp forests. Characterised by thick dark stripes running parallel along the length of its body, the pyjama shark is an unmistakably captivating animal and reaches lengths of just over one metre.
It is an opportunistic predator with a particular desire for chokka squid. These sneaky hunters have been observed gathering inside squid egg beds during mass spawnings, which peak from October to December each year. With their heads concealed amongst the egg masses, their elegant stripes camouflage them by breaking up their body outline. Unbeknown to the squid as they descend to the seafloor to tend to their eggs the pyjama shark launches its ambush attack and gains a tasty meal.
Like all catsharks, pyjama shark reproduction is oviparous with females producing brown eggcases – also known as ‘mermaids purses’ – which have sticky appendages that resemble strings and enable the eggcase to anchor itself within the kelp forest. It usually takes between five and six months for the young pyjama shark to be born once the eggcase has been laid.
The Women in Shark Science team doing a work up on a pyjama shark. A work up involves taking several measurements, inserting a spaghetti tag with a unique identification number, recording the gender and taking a fin clip for genetic sampling. The tag works on the principle of mark and recapture - if this individual is recaptured its measurements will be re-recorded to track growth rates and another fin clip will be taken.
Typically nocturnal, these exquisite catsharks can be difficult to see in the wild. On my previous snorkelling trips in South Africa I had never seen one, but fortunately last month we were treated to numerous individuals. As part of the South African Shark Conservancy’s tagging programme, in collaboration with the Oceanographic Research Institute (ORI), the pyjama shark is a focal species for their research in Walker Bay.
Not dissimilar from other shark species, the pyjama shark is unfortunately enlisted on the IUCN Red List as being Near Threatened; however, the last published population estimate at the time of writing was 2005 and so it goes without saying that this needs to be updated. Bycatch is seemingly the largest threat to this species, but many questions remain unanswered. Thanks to the work of the South African Shark Conservancy and other collaborators, we are closer to better understanding this mesopelagic predator.
Although a lot of unknowns remain surrounding this enchanting creature, one things for sure…
If you find yourself diving amongst the stunning kelp forests of South Africa, be sure to be on the look out for this predator – you won’t be disappointed.