Basking shark

The basking shark is the second larger fish after the Requin whale. Its size can reach 12 m length for an average length of 10 Mr.

Etymology

Cetorhinus comes from the Greek ketos , “monster marine” and rhinos , “nose”; maximus is Latin and wants to say large. It is the last survivor of the family of the Cetorhinidae .

Appearance

Its muzzle is very pointed, which explains the roots “rhinos” = nose and “maximus” of its name. This impression of point is still reinforced when the shark feeds, because its mouth opens under its nose.

Its mouth, naturally rather large, can open much more than that of the shark whale.

Its slits branchiales are enormous and can still dilate under the pressure of water that the shark filters.

Its color (bluish gray or bronzes) is rather dark.

Its first dorsal fin is large and triangular. It can atteintre up to 1,03 m (for the adults: cut higher than 7 m).

Food

It nourishes Zooplancton exclusively, (in particular Calanus helgolandicus ). It is one of the three species of sharks zooplanctophages.

The basking shark often nourishes itself on the surface, during the spring and the summer, in water from 11 to 14 °C (Sims and Quayle, 1998).

The studies continue to know its behavior and its winter activities. It is sure (thanks to radiotracking) that it does not hibernate the winter although former studies postulated it. Scientists of the university of Plymouth in England showed that the shark does not swim with the aveuglette, the open mouth to nourish itself, but that it is shown very selective. The shark would be câpable to detect rich zones zooplanctons some and of séléectionner the filtered species.

Protection

It is a species considered by the UICN as vulnerable but is not protected in France. only fishing and the unloading are prohibited following surpêche in the past. Only one French association works with its study and its conservation: the APECS (Association For the Study and the Conservation of Sélaciens), www.asso-apecs.org Based in Brest, it carries out each year a follow-up of manpower.

References

See too

External bonds

  • Some beautiful images

  • In English
  • association for the study and the conservation of the selacians

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