This is the tale of two brambles, one prickly and one spiny. One rare, the other so data deficient we don’t even know its conservation status! and neither bramble, a threat to human wellbeing. Through, this blog post we will uncover the little that is known about these two bramble shark species.
Hello Reader! I am sure by now you have uncovered that this blog post is not about the bramble plant, responsible for producing delicious blackberries, but is about the bramble sharks. The two species of bramble shark are classified as such because of the thorny, teeth like denticles that cover the skin, except for around the mouth and under the snout. Both species are also stout and flabby creatures, living in the deep sea. So we can forgive their unfriendly appearance… After all, they are adapted to live in a place where they never expect to have company. Indeed, the spiny bramble shark has not been photographed in its under water home. The only pictures I could find were of those who had been fished from their home and were covered in blood, so of course I did not want to show you those distressing images.
The spiny bramble
The first point I want to make about the spiny bramble shark is that it is so data deficient, that nothing is known about its conservation status. It is this reason why shark conservation and science is so vital. Especially when they are being taken from the sea when we have no idea about their numbers. We could be potentially losing this species forever. We do know that they reproduce slowly, so this could be a factor that could lead to their extinction, if we continue to be ignorant of their natural history. This has just given me the epiphany that I would like to specialise in deep sea sharks! (for context I want to be a conservationist and at my last interview a week ago I was told I need to find a niche, which freaked me out because I love all animals!)
Sorry for rambling and starting off the spiny segment on a depressing tone but here is what we know about the spiny bramble so far…
They dwell at the bottom of the deep sea and when they are found by humans it is at depths of 400 – 900 metres, on continental shelves. The range isn’t known in great depth (how ironic) but we think they swim around in the; North sea, West and East Atlantic, Indian ocean and the West pacific ocean. Now its biology time! They are a very sluggish species, but I suppose their Is no need to hurry in the pitch black of the deep. We don’t know a lot about their natural history but true to their sluggish character we expect them to be slow growing and late bloomers on the sexual front. We know that crustaceans, small sharks and bony fish are common prey for them, so think they must be possible of short bursts of speed, to enable them to catch their dinner! We know they are ovoviviparous (eggs hatch internally in mother) but we don’t know their gestation period, or what happens after birth.
The Prickly Bramble
So, here is what we know about the rare one…
Also a deep water species, the prickly bramble shark is classified by the IUCN Red List as Near Threatened. This is because deep sea trawlers catch them as by catch, and the likelihood of this happening could be on the increase. The Prickly’s live in tropical and temperate areas of the Pacific ocean, on sandy sea beds. They are found on insular and continental shelves at depths of 10-400 metres and have been known from depths of 1,500 metres before! Just like the spiny bramble the prickly bramble is also sluggish but is known to pick up the pace when prey is around. It feeds by sucking prey into it’s mouth, like the shark version of a vacuum cleaner. This bramble likes to eat for its supper; small sharks and their egg cases, crustaceans and small fish. The Prickly bramble is ovoviviparous and can give birth to 114 young at a time! Goodness gracious! Their young ones are born at 40 -45 cm in size, though this is all that is known about their reproduction and courtship. These sharks do sometimes migrate to shallower inland waters and the reason is absolutely unknown.
3 days to go…
In three days time I will be facing my fear of deep water to raise money and awareness for shark conservation. As you can see from this post, shark natural history is very under researched, which is why I am raising money for the Shark Trust. In tomorrows post I will be explaining to you why sharks are so fundamental to our eco-systems! If you want to know more about my fundraising story and show your support then you can visit my just giving page. But it really does mean so much to me that you are reading my posts and showing an interest in sharks!