Rare Shark Filmed in Japan

[TheBORG] writes "A Deep Sea Frill Shark, whose normal habitat is between 600 and 1000m, was found and filmed off the coast of Japan recently. Normally they're caught (found dead) in fishermen's nets. This 'living fossil' was probably so close to the coast because it was sick. In its poor condition, the shark was moved by marine park personnel to a seawater pool where they filmed it swimming and opening its jaws. The shark died a few hours later after being filmed."

Comments

1000m?

[COMON$]

Correct me if I am wrong but humans can go a bit deeper than 1000 feet as mentioned in the article.

http://www.ussubs.com/faq/luxury.php3 a small deep submersible could be carried "piggy back" by the Seattle, allowing a small group of 2-3 people to board the deep submersible through a transfer lock and dive to depths of up to 3000 meters or more.

Re:1000m?

[Nos.]

Wow, a little research, and I found this: http://en.wikipedia.org/wiki/Bathyscaphe_Trieste.. . deepest dive, at almost 11,000m. That's impressive.

Re:1000m?

[Sponge Bath]

... trying see anything in that pitch-black environment

Maybe they could use one of those machines that go 'ping'.

Re:1000m?

[FridayBob]

They mean humans with SCUBA equipment subjecting themselves to extreme ambient pressures -- not diving in submarines. Deepsea submarines have taken man to the very deepest parts of the oceans (about 11,000m), but the record for technical diving with special SCUBA equipment is 318.25m: a record set by South African Nuno Gomes in Dahab (Sinai, Egypt) in 2005. Such dives are very dangerous and require careful management of multiple gas mixtures composed of oxygen, nitrogen and helium (trimix) to prevent problems like nitrogen narcosis, oxygen poisoning and decompression sickness (the bends). Deep dives like this also last so long (Nuno's dive was over 12 hours) that lots of other problems, such as hypothermia and dehydration, have plenty of time to develop.

The deepest simulated dive is 685.5msw (meters of sea water) set at Duke Medical Center (Durham, North Carolina) by three divers in 1981. In cases like this, HPNS (high pressure nervous syndrome) is the limiting factor. HPNS is a syndrome of neurologic dysfunction with symptoms that include tremors, dizziness, vertigo, nausea, visual distortions and altered sleep. Tremors associated with HPNS have been reported as shallow as 128.72msw, but the deeper you go, the more likely HPNS is to occur. Eventually, it can prevent a diver from performing essential tasks during a dive.

Knowing this, you have to admire those sperm whales: mammals that are believed to be able to dive as deep as 3,000 metres and then go hunting for food at that depth!

Ah hah!

[dreddnott]

More proof that cameras steal souls!

Re:Ah hah!

[bn557]

Close, this was actually Schroedinger's Shark. Once they observed it, it's state became 100% dead, rather than a superposition of alive and dead. No Fair.

He's not dead

[spun]

He's pinin' for the fjords!

Video shot of the shark

[Pippen101]

http://youtube.com/watch?v=Qz_nZixWX6Q Youtube video of the shark

Re:Change in currents

[Brushfireb]

I don't understand why a shark would surface if it was sick, that would just make it more vulnerable to unforeseen predators.

This is quite common in *many* animal species. Even dogs and raccoons do this. Obviously, when a creature gets physically sick (or old), often they are also mentally deficient as well, just like humans. With animals, however, they often wander into strange places, away from others of their kind, and generally do things they wouldn't ever normally do. This can be attributed to loss of sensory capabilities, perception, and many other things.

In some ways, this is advantageous -- not to the individual creature, but to the overall population -- and can potentially be considered advantageous behavior. If a creature is infested with a disease, the further away it gets from its healthy kin, the better off they are likely to be. If the creature is just old, it can benefit the rest of the 'pack' by leading predators away, at very least, before it dies.

Back on topic... This thing looked pretty beaten up. Granted, I haven't ever seen one before, but it looks to me pretty old and out of it. It was just its time -- I wouldn't attribute its death to anything else unless you start seeing many more similar cases. Then it makes sense to worry. Until then, this is just kind of 'cool' for us monkeys.

B

Re:Change in currents

[adisakp]

I don't understand why a shark would surface if it was sick, that would just make it more vulnerable to unforeseen predators.

One of the first symptoms of many types of sickness in most species of fish is difficulty controlling their buoyancy. If you have a fish tank and your fish is sitting at the top or bottom of the tank and moving slowly, that's a good sign it's a sick fishy.

Re:Change in currents

[carpeweb]

I've had several dogs, and not one of them ever surfaced from 1,000 m just because they were sick or dying.

Re:Change in currents

[StikyPad]

I don't understand why a shark would surface if it was sick

This is quite common in *many* animal species. Even dogs and raccoons do this.

Only the ones that are witches. The rest of them stay on the bottom.

My theory

[Vicegrip]

Interesting, in the video it looks like it is keeping its gills crazy-open none-stop. It looks like its desperately trying to get enough water across its gills. Maybe it just died of exhaustion because of the effort? Kind of like what people go through when not used to mountain atmospheres and get out of breath fast.

My free guess: it almost got caught by a fishing net which wounded it. The damage caused the fish to become disoriented. Lack of oxygen further disoriented it and all it could to stay alive was try to get more water across its gills. Eventually it died from exhaustion.