The nice thing about being in charge of this blog is that I get to choose what name to use for the animals I write about. For most animals, there isn’t much of a choice, since there’s only one or two common names for many species. But for today’s animal, I have many options, and I choose to use its name ‘sea fox’, because that is by far the best name for any animal ever.
Sea foxes are a type of shark, and are probably better known as thresher sharks. Other names for these lovely guys are swingletails, slashers, swiveltails, and whip-tailed sharks. They are found all over the world, in tropical and temperate oceans. They are a coastal species, not venturing beyond depths of 110 m, and rarely going beyond 30 m from shore.
Sea foxes are the biggest of the thresher sharks, growing up to 6 m in length, though almost half of the sharks’ length is made of their tails. Thresher sharks have massively elongated upper tail fins, which have been rumoured to be used to smash and stun prey. When you have a mouthful of almost a hundred sharp teeth, I don’t know why you’d use your tail to attack prey, but there you go. Sea foxes are blue-grey on top, with white undersides.
Mating can occur year-round in sea foxes, with migratory threshers breeding in northern waters before heading south for the winter. The young sharks are born live, and are independent immediately after birth. Due to their small size, however, the baby sharks are vulnerable to predation, and thus stay in nursery waters until around three years of age. After 9-13 years the sharks reach sexual maturity and can have pups of their own.
Sea foxes use a variety of senses to navigate their habitat, relying on their lateral line to detect vibrations, a keen sense of smell, and of course, they have electromagnetic organs to sense things as well. They use these senses in combination to hunt their prey, which are usually small, schooling fish. The sharks use their giant tails to herd the fish into tight balls, which makes catching them a whole lot easier.
And now the part of the post you’ve all been waiting for: why the hell are these sharks known as sea foxes? Well, the term ‘sea fox’, or ‘fox shark’, was one of the first names given to these sharks, as it was thought to be especially cunning. It’s a bit of a silly explanation, but the name is so cool I’ll forgive the scientists or sailors who came up with it. It would have been better if they were a species of shark that looked like foxes, because foxes are super cute.
Cover image source: http://www.friendsofanimals.org/news/2014/august/foa-files-petition-protect-common-thresher-shark-under-esa