There are many remarkable facts about the sandtiger shark (also called spotted ragged-tooth shark in South Africa and grey nurse shark in Australia).

shark
© http://www.freenaturepictures.com

Did you know that the sandtiger shark:

  • is presumed to be the archetype of sharks since it is a long-standing popular exhibit in public aquaria,
  • is actually much less dangerous than it is rumored to be and it looks (especially due to its teeth),
  • is the only shark that can achieve neutral buoyancy, that means it can hover without swimming, by holding air in its stomach (gulped from the surface),
  • is the only shark species found to be able to survive finning (due to its neutral buoyancy, I think),
  • develops precocious teeth and swimming ability as a fetus in the uterus, enabling them to actually feed upon lesser siblings (the only known case of in utero cannibalism, where only one fetus in every uterus survives),
  • matures as a female at an age of at least 6 years and at a length of about 7 foot (2.2m) and give birth to two 3 foot (1m) long pups (since only one from each uterus survives),
  • gets less that 1 pup per year due to 2-3 year between births, that translates to the lowest reproductive rate of all sharks,
  • ceases to feed while pregnant (hydroids actually grow on the teeth, suggesting prolonged lack of use),
  • has been killed in unprecedented numbers in the seventies with spearguns and explosive underwater powerheads while hovering peacefully in large herds like grazing cattle (and sometimes these days, still),
  • is therefore considered near threatened in the west coast and critically endangered in the east coast of Australia (the subpopulations are separated) and also critically endangered in the southwest Atlantic and was the first protected shark in the world, now a protected species in Australia and in the western North Atlantic.

Sandtiger shark meat is considered a delicacy in Japan. As if that weren’t enough, here is a report of the rescue of a sandtiger shark tangled in our waste.

Sources: here and here

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