UNIQUE. It is the kissing monster of the abyss: with its long flattened nose and telescopic jaw with nail-shaped teeth, the Lutin shark, or goblin shark (Mitsukurina owstoni) is a curiosity of nature. A rare and unique species, as it is the only survivor of the Mitsukurinidae family. Probably 3 to 4 meters long as an adult, this deep-sea shark is still very poorly known: only about a hundred individuals have been caught so far. These sharks are accidentally found in fishermen’s nets and trawls in various parts of the world, such as in Japan, where it was described in 1898, New Zealand or Mexico. The species is not considered threatened. The International Union for the Conservation of Nature (IUCN) considers that human fishing activities have little impact on the populations of thresher sharks. In the blind depths of the ocean, the beast prowls the continental slopes, mounts and underwater canyons in search of crustaceans (shrimp, crabs), cephalopods (octopus, octopus) and especially fish.
A nose studded with Lorenzini’s famous blisters.
Its flaccid body, its not very rigid skeleton and its small fins suggest that the Lutin Shark is a slow swimmer: it would catch its prey by surprise. By means of organs specific to sharks called Lorenzini’s blisters, it would detect its prey thanks to the weak electric field they emit in spite of themselves while breathing. Light and silent, the animal would sneak up to its prey… Then, suddenly extending its retractable jaw, the shark would swallow its victims raw. It is precisely to better “feel” its environment that the Lutin shark would have developed its long soft snout so curious. A nose studded with those famous Lorenzini’s blisters, all the more useful as the shark probably does not use its eyesight much, given the meager space dedicated to this sense in its brain. The animal probably cannot rely on its eyes to be wary of the blue shark (Prionace glauca), its natural predator. As for the reproduction of the Pinocchio shark, it remains very poorly known. If it shares the characteristics of its cousins, the animal is probably viviparous, i.e. the female gives birth to small sharks, which would perhaps measure around 82 centimeters long, the size of the smallest specimen caught to date.
A good fossil is a dead fossil.”
This strange creature with a prehistoric appearance would have evolved very little physically since the Cretaceous (145 to 66 million years before our era): its ancestors were contemporaries of the dinosaurs! The goblin shark has even inherited the title of “living fossil“, like the coelacanth (Latimeria spp.), a mythical African fish, the nautilus (Nautilus macromphalus) or the Ginkgo, known as the “tree of forty écus” (Gingko biloba). A name that bristles the hairs of certain scientists, such as biologist Patrick Laurenti, lecturer at the University Paris Diderot. “A good fossil is a dead fossil,” he says on the blog of his colleague Pierre Kerner, Strange Stuff And Funky Things. This term of living fossil “wrongly suggests that species have not evolved for tens of millions of years,” he writes. Which is obviously false: evolution is a continuous phenomenon; moreover, it is not limited to the appearance of a species. “Only 5% of genes are involved in the appearance of an organism,” the researcher explains. We can add that a true fossil remains frankly uninformative on many appearance criteria! Who can tell us that the shimmering scales of the coelacanth have not changed?”
Beyond even these objections, the biologist realized that in coelacanth, such a qualification is a real myth since there are no fossils of this species and those that are closest to it have a very different appearance, which suggests that current coelacanths have indeed evolved and continue to do so, as he explains in a study published in 2013 in the journal Bioessays. While there is no evidence to support (or refute) such a line of reasoning on the Lutin shark, it would seem more prudent to dispense for the time being with the qualifier “living fossil“. The goblin shark is no less fascinating… and certainly, it still holds many surprises in store for us!