Showing posts with label shark. Show all posts
Showing posts with label shark. Show all posts

Wednesday, December 21, 2016

Rare Ghost Shark was filmed for the first time in Gulf of California - PHOTO, VIDEO

It looks like something out of a horror movie, with two dead eyes peering out of a pale patchwork of flesh, but that's a perfectly happy 'ghost shark' - otherwise known as a spookfish - cruising about in the deep sea off the coast of California.

The species, which features retractable sex organs on its forehead, has never been seen on film before.

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The individual has been identified by researchers at the Monterey Bay Aquarium Research Institute (MBARI) as Hydrolagus cf. trolli - known commonly as the pointy-nosed blue chimaera.


Chimaeras: Strange Fish With a Cartilaginous Skeleton Owlcation

The "cf." in its species name indicates that its physical characteristics closely match the official species description for Hydrolagus trolli, but without DNA evidence, they can't be sure.



In fact, there's also the possibility that this isn't just the first ever footage of a live Hydrolagus trolli - it could be showing us an entirely new species of ghost shark.

But because these fish are usually too large, fast, and agile to be caught by deep-sea roving vehicles, it's going to be incredibly difficult to find out for sure.

"If and when the researchers can get their hands on one of these fish, they will be able to make detailed measurements of its fins and other body parts and perform DNA analysis on its tissue,"

"This would allow them to either remove the cf. from their species description, or assign the fish to a new species altogether."

The footage was captured by an autonomous rover in the Gulf of California back in 2009, and researchers have only just released it to the public.

The creature is a chimera - an order of deep-sea fish that split off from sharks in the evolutionary tree nearly 400 million years ago, and has remained isolated ever since.

Chimaeras live on the ocean floor at depths of up to 2,600 metres (8,500 ft), and they have a permanent set of 'tooth plates' to grind their prey into pieces, unlike the conveyer belt of replaceable teeth found in sharks.


But perhaps their most creepy characteristic are the deep grooves cut into their flesh that make them look like something a serial killer stitched together:


Photo: MBARI
Until now, the pointy-nosed blue chimaera has only ever been identified in the southwestern Pacific Ocean, particularly around Australia, New Zealand, and New Caledonia, from specimens dredged up in fishing nets.

This new footage now suggests that the species has a much wider range than anyone had expected, and hints that it could range even further away from its known haunts have made researchers hopeful that it's not rare - just good at hiding.

In reality, those grooves are called lateral line canals, and they form a system of open channels on the heads and faces of ghost sharks.

They're thought to contain sensory cells that help these creatures detect movement in the pitch-black water.


You can see another view of them here, including the rows of dots that are also thought to be tiny sensory organs:


Photo: MBARI


"Similar looking, but as yet unidentified, ghost sharks have also been seen off the coasts of South America and Southern Africa, as well as in the Indian Ocean," Fulton-Bennett reports.

"If these animals turn out to be the same species as the ghost sharks recently identified off California, it will be further evidence that, like many deep-sea animals, the pointy-nosed blue chimaera can really get around."

The sighting has been described in Marine Biodiversity Letters


You can see more footage of a ghost shark below - this species has a distinctive purple hue, and a serious parasite problem:




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The above post is reprinted from materials provided by Sciencealert . Note: Materials may be edited for content and length.

Saturday, August 20, 2016

The greatest longevity on Earth. It Has 400 years.

Researchers have found that elusive Greenland shark can live up to 400 years in the depths of the Arctic Ocean.

In perspective, this case proves that sharks living today have lived through the Mayflower brought the first pilgrims to America or when Isaac Newton developed the first theory of gravity. By analyzing 28 female sharks in Greenland proved that the oldest copy was at least 272 years and not more than 512 years and is one of the oldest animals with a backbone known to mankind. Researchers have predicted that the female was about 390 years old when he was captured accidentally by a research vessel.

Before this, the longest vertebrate whale head was arched, which can live up to 211 years.

In the new study it has suggested that the Greenland shark can survive two or more years than whale head arched. Future research could reveal secrets scientific world slowing the aging process of humans. Greenland shark is a carnivore that lives in the freezing waters of the Arctic Ocean. Shark increase over five meters in length and swim slowly in the deep, icy, only coming to the surface to feed a big fish or a marine mammal, such as seals.

These sharks can live a longer period of time due to slow growth process (one centimeter per year), but very difficult to see, researchers have never been sure of this theory.

,, We have expected that sharks must be very old, '' said principal investigator, Julius Nielsen, University of Copenhagen, Denmark. ,, But not long before I knew, of course was a big surprise to discover that it is the longest vertebrate, '' he added.

To make this claim, researchers analyzed 28 female Greenland shark, caught between 2010 and 2013. The normal aging process of the Greenland shark is not the same as other vertebrate Since we have these layers calcified tissues increased. Nielsen discovered a series of proteins crystallized in the eye, which were formed during their life.

The team tried not to give too many figures, but said that two of the older subjects were between 335 +/- 392 +/- 75 and 120 years. Which means that the oldest female was around 272-512 years.

The discovery has both positive and negative aspects, the negative aspect is that they reach sexual maturity at the age of 150 years, which means that any shark killed by fishermen or climate change can be very difficult to replace.

,, Our results have shown that the Greenland shark is the longest vertebrate, our concerns are growing because species must be preserved, '' team concludes.

 The good news is that by studying the life cycle of these species, researchers can conserve better in the future.

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Source: Science Alert