Posts tagged: ocean
by Miguel Mansur (via: Juxtapoz)
pleasantly calm or peaceful; unruffled; tranquil; serenely quiet or undisturbed.
fuck i want a undersea whale castle of love
Headshield Sea Slug, St. Thomas, U.S. Virgin Islands.
(via: LiveScience) (Photo: Ximena Olds)
Cratena peregrina, a nudibranch, Chalkidiki, Greece. This species is distinguished by two bright-orange marks at the base and tip of each of its tentacle-like structures called rhinophores. C. peregrina is believed to be hermaphrodite.
(via: LiveScience) (Photo: Nicholas Samaras)
The largest member of the dogfish family, the Greenland shark can grow to over 20 feet in length. This shark prefers cold-water temperatures and will usually only ascend from the depths if the surface drops to around 33 degrees Fahrenheit. Also called the “sleeper shark,” this species is often inactive and indeed appears to be sleeping. As its name indicates, the Greenland shark is found around Greenland, but it also exists in other parts of the North Atlantic, such as near Iceland. Life may seem to be lonely in the ocean depths, but this shark often is found with a “best friend forever,” a parasitic copepod that lives on the shark’s eye and feasts on its corneal tissue. While the shark does suffer some damage, the relationship affords benefits. The parasite is bioluminescent. Its glow helps the shark to attract prey, similar to how a colorful fishing lure may attract fish.
Fish constitute the largest portion of the Greenland shark’s diet. They may also consume large sea mammals, such as seals. If something looks like food, however, this shark will gobble it down. Some Greenland shark stomachs have contained pieces of horses and polar bears. One shark even consumed an entire reindeer, antlers and all. These incredible Greenland Sharks can survive for more than 200 years at depths of up to 600 metres under Arctic ice.
Cool Fact - The size of the largest known Greenland sharks remains in dispute, with some scientists believing this species could exceed many great white sharks in length.
Sand bubbler crab
Sand bubbler crabs live in burrows in the sand, where they remain during high tide. When the tide is out, they emerge on to the surface of the sand, and scour the sand for food, forming it into inflated pellets, which cover the sand. The crabs work radially from the entrance to their burrow, which they re-enter as the tide rises and destroys the pellets.
Human Origins Traced to Worm Fossil In Canada?
by PhysOrg staff
Paleontologists have traced the origins of humans and other vertebrates to a worm that swam in the oceans half a billion years ago, said a study published Monday (3/5/12).
A new analysis of fossils unearthed in the Canadian Rockies determined that the extinct Pikaia gracilens is the most primitive known member of the chordate family, which today includes fish, amphibians, birds, reptiles and mammals. The research published in the British scientific journal Biological Reviews identified a notochord or rod that would become part of the backbone in vertebrates, and skeletal muscle tissue called myomeres in 114 fossil specimens of the creature.
They also found a vascular system… “The discovery of myomeres is the smoking gun that we have long been seeking,” said the study’s lead author, Simon Conway Morris of the Cambridge University. “Now with myomeres, a nerve chord, a notochord and a vascular system all identified, this study clearly places Pikaia as the planet’s most primitive chordate. “So, next time we put the family photograph on the mantle-piece, there in the background will be Pikaia.”
The first specimens of Pikaia were collected by early explorers of the Burgess Shale in 1911. But the animals were overlooked as an ancestor of earthworms or eels. It was not until the 1970s that Morris suggested the five-centimeter (two inch) long, sideways-flattened, somewhat eel-like animal that likely swam by moving its body in a series of side-to-side curves could be the earliest known member of the chordate family…
(read more: PhysOrg) (images: Cambridge Univ.)
More information: Pikaia gracilens, Walcott, a stem-group chordate from the Middle Cambrian of British Columbia, Article first published online: 4 MAR 2012. DOI: 10.1111/j.1469-185X.2012.00220.x
dailyfossil: Herpetogaster collinsi
Reconstruction by Marianne Collins
When: Mid Cambrian (~505 million years ago)
Where: British Columbia, Canada.
What:Herpetogaster is yet another one of the odd fossils found at the amazing Burgess Shale fossil locality in British Columbia, Canada. This amazingly weird form is known from several complete specimens, so as strange as its anatomy is, that is what was really there, there is very little speculative interpretation! The body of Herpetogaster is roughly 1-1.5 inches (~3-4cm) long, and is thought to have been tough but flexible in life. The animal had a fairly clearly defined head region, with a centrally located mouth, with a paired set of tentacles on either side. These tentacles are thought to have been softer and more flexible than the relatively firm shaft of the main body. These two main tentacles had many sub-branches and would guide food towards the oral cavity. It is unknown if Herpetogaster was a pure filter feeder or if these tentacles actively ensnared small prey that swam too close in the Cambrian seas. The animal was attached to the substrate by a stolon or hold-fast. A number of Herpetogaster specimens have been found together on a single slab, indicating this animal lived in groups.
Herpetogaster has been placed as a stem Ambulacraria. This is the group that includes echinoderms (starfish, sea urchins, sea cucumbers, etc) and hemichordates (acorn worms). As the living and fossil species in these groups of animals look very different from one another, the identification of a stem member is extremely important for our understanding of the evolution of both groups and helps to answer some questions about the poliarty of character states within each group. For example Herpetogaster is bilaterally symetrical, so therefore it shows that the radial symmetry of the echinoderms is a ‘new thing’ and that the bilaterally symmetry of the acorn worms is the primitive condition, and not a reversal. Additionally, knowing the morphology of a stem taxa on this branch will hopefully lead to the identification of the proper phylogenetic position for other ‘Problematica’ fossils in the Burgess Shale and other Cambrian (and older!) deposits.
And for more of Herpetogaster specifically, go to the Royal Ontario Museum’s page on the specimen:
They have some great animations!
wait does its name mean ‘snake eater?’
How to Say ‘In Your Face’ Like a Penguin
by Jane J. Lee
Like a football player who just scored a touchdown, male white-flippered penguins (Eudyptula minor albosignata) perform triumph displays after defeating an opponent. Now, researchers in New Zealand have found that those victory dances, complete with a braying, donkeylike call and flipper waving, make it less likely that nearby penguins will challenge the winner.
“Scientists have spent a lot of time studying antagonistic interactions, but quite often, they turn the camera off after the fight, so they miss a lot,” says Tom Sherratt, an evolutionary ecologist at Carleton University in Ottawa, who was not involved in the current study. Researchers have investigated the effects of triumph displays on the loser, but because this is a fairly recent field of study, the new research is probably the first published account of its effects on nearby birds, he added.
Explanations for the function of triumph displays include browbeating an opponent so that he doesn’t forget who beat him and signaling to an audience not to mess with you…
(read more: Science NOW) (photo: Joseph R. Waas, Waikato Univ.)
When: Cambrian (~505 million years ago)
What: Fasciculus is yet another fantastic fossil from the Burgess Shale fossil site in BC, Canada. It is extremely rare, with only one known specimen. This single specimen was found in 1917, but not fully described in detail until 1996. It is about 4.5 inches (11.4 cm) wide, and is perserved in intricate detail.
Unlike most fossils from the Burgess Shale, Fasciculus is confidently linked to a living group. It is placed as a stem Ctenophora,which are the comb-jellies. Comb-jellies are not closely related to ‘normal’ jellyfish, which fall into the cnidaria along with the hydras. Ctenophoras are cup-like animals that swim though the water, with multiple sets of cilia arranged in longitudinal series, so that they resemble combs, giving them their common name of comb-jelly. In Fasciculus you can see these rows wonderfully preserved. The discovery of a stem member of this lineage once again shows that most, if not all, modern phyla were well separated even as long ago as the Cambrian.
For more read up on this very rare fossil and its contemporaries at: http://burgess-shale.rom.on.ca/en/index.php
Reconstruction by Marianne Collins