The Earth Story

How do Octopuses crawl?

Researchers at the Hebrew University of Jerusalem have filmed octopuses (or octopi) and analysed their movements, revealing how they crawl. The fact an octopus can crawl is remarkable since they lack a ridged skeleton. They move forward by shortening and lengthening one tentacle in their chosen direction using its suckers to grip. Therefore it picks one of its 8 legs that is closest to the direction it wishes to move in. This type of movement is similar to how some molluscs move and has no notable rhythm or pattern to limb movements. However the researchers did notice that some of the octopuses appeared to have a favourite pair of arms that they’d use together and do preferentially use their four back tentacles to move. This information could be useful to engineers seeking to build soft-bodied robots. These robots could be utilised in the fields of medicine and rescue. It would be particularly useful in confined spaces, for example in a collapsed building where soft bodied arms could access narrow spaces. ~SA

Picture: http://bit.ly/1OUy9tH A mimic octopus by Silke Baron from Vienna, Austria Video: http://bit.ly/1EegR9a by musiclovenature Paper: http://bit.ly/1b8nP2f

A moment of mass death

The bullet shaped fossils known as belemnites are the guards of an extinct order of Mesozoic predators that resembled squid or cuttlefish, and lived from the early Jurassic to the late Cretaceous. In some places they are very useful for establishing the stratigraphy, since, in a similar manner to ammonites, they evolved fairly rapidly. Their changing forms can guide us to which exact period the rocks in question date from. Such identifications are invariably made on the basis of as complete a faunal assemblage as possible, but since many of the organisms used are microscopic, belemnites and other easily identifiable larger fossils serve as an excellent rough and ready field guide to the knowledgeable geologist. The round shape is the vertebra of an ichthyosaur.

Belemnites had 10 equal sized tentacles studded with hooks to ensnare prey, without the two longer ones that characterise modern squid. They also had internal skeletons made of calcite, unlike their modern counterparts, and the most commonly fossilised part pictured here was at the rear of the animal. Rare examples with preserved internal parts indicate that they had ink sacs, hard beaks, large eyes and tailfins similar to modern cephalopods. They are often found in the stomachs of larger predators such as ichthyosaurs.

They have intrigued humans since time immemorial, and were called thunder stones in England (as they were thought to fall from the sky), along with bullet stones, and both the devil's and St Peter's fingers depending on religious inclination. The Chinese called them sword stones and the Scandinavians gnome's candles, testifying to the interest paid to these odd shaed rocks around the globe. Belemnites are also the state fossil of Delaware.

Loz

Image credit: LGF Foundation http://lgffoundation.com/ http://www.ukfossils.co.uk/guides/belemnites.htm_ _

Octopus hunting

Floating Portugese Man of War, or according to Wikipedia also called blue bottle, or floating terror. The stings from those tentacles can be extremely painful even lethal.

A stately creature

The largest jellyfish species on our planet is a beastie that loves frigid waters, both northern and southern, and is known as the Lion's Mane or hair jelly (though Pastafarians might join me in seeing another living representation of their deity, to accompany the sinophore we shared at http://on.fb.me/1P4kLBu). With a bell up to 2.5 metres across and clustered tentacles up to 37 metres long (more than a blue whale), these predators drift around the world's icy seas eating fish and other small marine creatures that it stings with its tentacles, stunning them while it engulfs them in its maw.

They live for a year or so, spending most of their lives pulsating along near the surface in deeper waters following the currents and settling in shallow sheltered bays towards the end of their span in early autumn. They breed both sexually and asexually, passing through four stages in their seasonal life: larva, polyp (asexual), ephyrae and medusa (sexual). Eggs are carried in tentacles, and hatch into larvae, whereupon the medusa deposits it on a suitable surface. They grow into polyps, reproduce into ephyraes and break off to grow into the full blown majestic medusa phase.

They can act as floating oases in the deep ocean, being surrounded by a halo of shrimp and fish all seeking fodder and protection from those that would eat them. In turn, they are eaten by seabirds, turtles and large fish. They are also bioluminescent, maybe using the light to attract prey or mates at night.

Scientists are still debating whether there are several species differentiating in the various regions of its range, or one. They vary in colour, blue, orange, red and purple being common, with size being the critical factor (the whoppers are red to purple). Their sting is painful but usually causes no lasting damage, as with all stings vinegar or coca cola poured onto the affected area should bring some relief. One should still consult a doctor after encountering one, due to the large number of potential stings.

These lovely creatures were snapped in Russia's White Sea

Loz

Image credit: Alexander Semenov/SPL/Barcroft Media http://bit.ly/1Pqs2iP http://bit.ly/1m5Wu5U http://bit.ly/1VyaBwS http://bit.ly/1m5Wu5U

Has God been found?

Those of us with a slightly warped sense of humour have derived enjoyment in recent years from the satirical religion known as Pastafarianism or the worship of the flying spaghetti monster, but they may have been revealing more than they realised, since an animal resembling their deity has turned up live and floating a thousand metres down in the sea off the coast of Angola. Filmed by a BP well maintenance team using a ROV, Bathyphysa confira is an example of a marine order called siphonophores.

These creatures are relatives of the polyps in corals and jellyfish, belonging to the phylum Cnidaria, and are colonial animals. The critter you see before you is not a single entity but a mass of cooperating cells, each of which have differentiated just enough to specialise, though they are bound together enough to count as one being, being unable to survive solo. Specimens up to 40 metres long have been spotted making them some of the largest critters on Earth. These predatory creatures are very fragile, and many are bioluminescent. Like jellyfish they capture prey with their oddly shaped tentacles.

As long as another tentacled deity that is reputed to live in a lost city deep under the Pacific Ocean near Ponape doesn't turn up in a camera, I can live with submarine irony gods.....

Loz

Image credit: BP screengrabs from their dive film.

http://bit.ly/1P72AvJ http://bit.ly/1UGOXqO http://bit.ly/1IMPjXy http://www.siphonophores.org/

VIRGA CLOUDS

No, these are not jellyfish floating in the sky – the ‘tentacles’ that are hanging down from the clouds are called "virga". High clouds can produce snowfalls that evaporate in the warmer and drier air below them, long before they reach the ground. When this occurs, virga can form; they are tendrils of ice crystals (or droplets) that can have a wavy appearance when they fall through wind currents. The tendrils are rain or snow that evaporates before reaching the ground, falling from clumps of Altocumulus clouds.

Virga can sometimes hang in the air long after the clouds that they formed from have dispersed; other times they dangle beneath their cloud bodies like jellyfish. ... The image shows clouds and virga at Sunset' Great Moulton, Norfolk. UK.

-TEL

http://www.newscientist.com/gallery/dn17178-extraordinary-clouds http://cloudappreciationsociety.org/virga-october-’05/

Image: © Karen Bilton

https://www.facebook.com/cloudappreciationsociety?ref=ts&fref=ts http://cloudappreciationsociety.org/

How do Octopuses crawl?

Researchers at the Hebrew University of Jerusalem have filmed octopuses (or octopi) and analysed their movements, revealing how they crawl. The fact an octopus can crawl is remarkable since they lack a ridged skeleton. They move forward by shortening and lengthening one tentacle in their chosen direction using its suckers to grip. Therefore it picks one of its 8 legs that is closest to the direction it wishes to move in. This type of movement is similar to how some molluscs move and has no notable rhythm or pattern to limb movements. However the researchers did notice that some of the octopuses appeared to have a favourite pair of arms that they’d use together and do preferentially use their four back tentacles to move.

This information could be useful to engineers seeking to build soft-bodied robots. These robots could be utilised in the fields of medicine and rescue. It would be particularly useful in confined spaces, for example in a collapsed building where soft bodied arms could access narrow spaces. ~SA

Picture: http://bit.ly/1OUy9tH A mimic octopus by Silke Baron from Vienna, Austria Video: http://bit.ly/1EegR9a by musiclovenature Paper: http://bit.ly/1b8nP2f

Carnivorous plant tentacle in amber The evolutionary history of those plants that use a variety of strategies in order to catch and dissolve insects in order to obtain nutrients is little known, as fossils are rare. Their ancestors grow nowadays in nutrient poor environments, such as anoxic bogs, and therefore have to supplement the sugars they get from photosynthesis with animal nutrients. They are the only known reversal in 'the natural order of things' whereby animals eat plants.  The earliest evidence found (so far) for their existence is this fossil sticky hair, found alongside a couple of leaves of a Venus fly trap (the ones that snap shut around an insect rather than entice it into a bowl of digestive juices) entombed in Baltic Eocene amber (47-34 million years ago) found near the Russian enclave of Kaliningrad. They were discovered as part of a project to use amber inclusions to reconstruct the Eocene ecosystem. The project has obviously been divided between palaobotanists and palaeoentomologists.  This tentacle was coated in natural glue, and is designed to trap any part of a desperate buzzing insect that it contacts as it desperately tries to free itself from its predator's deadly embrace while digging itself in deeper into the mire. Previously these plants were thought restricted to Africa, where their modern descendants are found, so finding examples from Europe came as a surprise. The discovery also helped calibrate a molecular clock, which suggests that the gruesome family has been around for at least 38 million years.  Loz Image credit: PNAS and University of Göttingen/Alexander Schmidt. Original paper, free access: http://www.pnas.org/content/early/2014/11/25/1414777111