Did you know that there is a shark specie coming up to the surface to bask in the sun? It’s the basking shark.

Basking_Shark_(eats_plankton)
Basking Shark

It is the second largest living fish and related to the great white shark – but it filters plankton solely by swimming with it’s mouth wide open using bristle-like gill rakers (which it sheds in winter and re-grows in spring – the only example for annual molt in fish). It’s dermal denticles are unique: they seem to be set into the skin at random, pointing every which way (instead of uniformly tailward).

They has been killed for centuries (in Ireland for their liver oil and in Canada because they unintentionally destroyed fishing nets) and are now on the IUCN Red List as Vulnerable. They are protected in many countries, but still die for shark fin soup, aphrodisiac, medicine and cosmetics.

Tagging showed that basking sharks wander from the United States as far as Brazil despite having to cross warmer waters near the equator (usually they only like water temperature up to 58°F).

They have an extremely low genetic diversity, that means all found basking sharks belong to the same population, even ones from Australia. That is bad for a healthy reproduction  and for the possibility of an adaptive change to survive in a changed environment.

Sources: this video and this informative website

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