National Geographic has posted this cool new video of an Amphioctopus marginatus, aka the Coconut or Veined Octopus, using a coconut shell as protective camouflage. I’m not exactly sure why it’s news, since I’m pretty sure this behavior has been well-documented for a while now, but this video is all kinds of awesome! (See my previous posts about the Coconut Octopus, here and here.)
Thanks for the link Natalie!
Video by Brian Wysor of the Bocas Research Station, Bocas Del Toro, Panama
(Via BoingBoing)
Unfortunately, they don’t say what species this is, but this is an amazing example of the versatile camouflage ability of the octopus. What I find most interesting about this video is not that this octopus has altered its physical appearance to mimic seaweed, but that it is also acting like seaweed—drifting back and forth in the tide.
We interrupt Halloween Week to bring you this exciting news bulletin:
Sperm Whales have finally been photographed feeding on Giant Squids!
It has long been known that the Giant Squid was on the menu of Physeter macrocephalus, the Sperm Whale, but the legendary encounter has never been captured on film. Before the first specimens of Architeuthis were described by science, whalers would find their remains among the stomach contents of harvested Sperm Whales, and those whales would sometimes bear enormous sucker scars. There were even reports from sailors who claim to have witnessed the two leviathans locked in mortal combat, and the image of squid vs. whale has become iconic.
Underwater photographer Tony Wu photographed a pod of six whales—five adults and a calf—in the waters off Japan’s Ogasawara Islands (the same area where scientists filmed a living Giant Squid for the first time back in 2005). Dr Mark Norman speculates that the adults were in the process of teaching the young whale how to dive and hunt for food. Recovered nearby was one of the squid’s 3.5 meter long tentacles.
See these amazing photos at The Daily Mail Online.
I can’t think of a better way to kick off Halloween Week than with a look at Vampyrotheuthis infernalis, the enigmatic deep-sea cephalopod whose name literally means “vampire squid from hell!”
V. infernalis is the only known living representative of the Order Vampyromorphida, and, despite the common name “Vampire Squid,” it is considered a closer relative to the Octopoda (octopuses) than the Decapodiformes (squids and cuttlefish). It is also not actually a vampire, but this small (~1 foot long) cephalopod is still wonderfully creepy.
Here’s why…
The Vampire Squid is sometime referred to as a “phylogenetic relict” because it possesses features thought to have been shared by the primitive ancestors of both octopuses and squids. Fossils from Middle Jurassic deposits in France indicate that vampyromorphids go back at least 165 million years.
This awesome replica of a turrilitid ammonite is from the Cretaceous Seas diorama at the American Museum of Natural History in New York City. I don’t know exactly which type of turrilitid this is, but my best guess is the genus Pseudhelicoceras.
Members of the ammonite family Turrilitidae are characterized by shells that are not typical tight spirals—a condition known to paleontologists as heteromorph. It isn’t clear what ecological niche the turrilitids filled, but at least some species are thought to have drifted up and down in the water column. They lived world-wide during the late Cretaceous period, but, like all ammonites, they went extinct in the same global catastrophe that killed off the dinosaurs 65 million years ago.
Octopus Day was two days ago, and here, at long last, is my contribution. Better late than never, I suppose!
Like all cephalopods, octopuses (and yes, that is the correct pluralization of the word) are amazing and fascinating creatures. They are among the most intelligent invertebrates (if not the THE most intelligent), and experiments have shown that they have both short-term and long-term memory and can solve puzzles and mazes. The complex octopus nervous system also accounts for their lightning-fast reflexes, keen eyesight, and astounding camouflage abilities.
The earliest known octopus fossil dates from the Carboniferous period approximately 296 million years ago, and today there are around 300 known species. Octopuses inhabit all of the world’s oceans—from shallow tide pools to the abyssal plains.
Here are eight species that I find particularly cool:
1. Enteroctopus dofleini
photo from www.marinebio.com
Common name: North Pacific Giant Octopus
Inhabiting the chilly waters of the northern Pacific is the mighty Enteroctopus dofleini. With a scientifically verified record weight of 71 kg (156.5 lb), it is generally considered the world’s largest octopus. (Although the rare Seven-Arm Octopus may hold a legitimate claim on that title.) A more typical size for an adult Giant Octopus is around 15 kg (33 lb), with an arm span of up to 4.3 m (14 ft)—still significantly larger than just about any other kind of octopus. Their diet consists of crustaceans, bivalves, and fish, and they have even been observed preying on sharks! With an average life span of 4-5 years, the North Pacific Giant Octopus is actually one of the longest lived octopus species.
2. Thaumoctopus mimicus
Common name: Mimic Octopus
Unknown to science until its discovery in Indonesian waters in 1998, T. mimicus has been observed mimicking both the movements and physical aspects of as many as 15 different species. I’d go into more detail, but you really should just watch the video. The typical coloration of a Mimic Octopus is white and reddish-brown stripes, and the they can grow up to 2 feet in length.
3. Hapalochlaena sp.
photo from www.underwater.com.au
Common name: Blue-ringed Octopus
The genus Hapalochlaena, which consists of at least three species, is found in tide pools across the western Pacific ocean. The common name of this octopus obviously comes from its striking coloration—blue rings (and stripes in one species) on bright yellow. It’s a good thing that these little octopuses are marked so vividly because they are one of the most venomous creatures in the world. Although it has been recently found that all octopuses (as well as cuttlefish, and some squid) are venomous, only the Blue-ringed Octopus is deadly to humans. Despite their tiny size (the largest species only grow to about 5 inches), a single individual contains enough venom to kill as many as 26 adult humans. For those unlucky enough to be bitten, death from respiratory paralysis and cardiac arrest can come in a matter of minutes, and there is no known antivenin.
4. Argonauta sp.
photo by Bernd Hofmann (from Wikipedia)
Common name: Argonaut, Paper Nautilus
Argonauts live in the open ocean in tropical and sub-tropical waters world-wide. Unlike most other kinds of octopus, Argonauts live near the surface, and in Classical times it was believed that they used their specialized shell-secreting arms as sails. It is their shells, which are actually egg cases produced by the female Argonaut, that give them their other common name: Paper Nautilus. Despite the uncanny visual similarity to the shells of the Chambered Nautilus and those of extinct ammonites, the Argonaut egg case is very different biologically (and mineralogically) from a true shell. Interestingly, the Chambered Nautilus was so named because of its apparent similarity to the Argonaut, even though we now consider the former to be the “true” Nautilus. There are at least six extant species of Argonaut, with several more known from the fossil record.
5. Grimpoteuthis sp.
photo from www.dfo-mpo.gc.ca
Common name: Dumbo Octopus
Belonging to the Octopus suborder Cirrina, the genus Grimpoteuthis consists of over a dozen rare and poorly-known species, all of which are found in the extreme depths of the ocean. They are small, not getting much bigger than 20 cm (8 in), and their common name comes from the ear-like pair of fins (present in all cirrate octopuses, but generally larger in the Dumbos) which are used to assist locomotion the same way a squid uses its fins. Like other cirrate octopuses, the arms of the Dumbo Octopus are completely webbed, and they also retain an internal shell, something the more common incirrate octopuses (i.e. every other kind of octopus) have lost entirely. Dumbo Octopuses spend their time either sitting on the sea floor, or swimming just above it searching for food.
6. Amphioctopus marginatus
photo by Nick Hobgood (from Wikipedia)
Common name: Coconut Octopus, Veined Octopus
Inhabiting sandy the bottoms of tropical lagoons of the western Pacific, A. marginatus often hides from potential predators by building itself a protective fortress out of debris from its environment. It seems to be particularly partial to coconut shells, and that’s the reason why one of its common names is the Coconut Octopus. (The other name is a reference to its dark vein-like color pattern.) In recent years, the Coconut Octopus has been observed walking bipedally. In one instance, one was seen to literally run across the sea floor on two arm while the rest of its body mimicked the shape and texture of a coconut! (The same report also includes a video of an individual of another species—Abdopus aculeatus—which was filmed walking backwards on two arms while adopting a posture reminiscent of floating algae.)
7. Tremoctopus sp.
photo from cameronmccormick.blogspot.com
Common name: Blanket Octopus
Behold the beautiful and otherworldly Blanket Octopus. Like the Argonauts (to which they are closely related), they live near the ocean’s surface, and can be found in both tropical and subtropical waters. There are four known species (the one depicted here is apparently T. gracilis, aka the Palmate Octopus), all of which share the same astounding anatomical and behavioral traits unique to this genus. Let’s begin with the name. As should be obvious from the image above, the female Blanket Octopus has two arms (the dorsal and dorsolateral, if you want to get technical about it) which are significantly longer than the rest and are connected to two other arms by a massive sheet-like membrane (the webbing is absent from the other four arms). It seems this “blanket” is unfurled when the animal feels threatened, presumably to make it appear bigger to any potential predator. Young individuals practice an altogether different defensive strategy. Apparently immune to the venom, they have been observed to carry pieces of the stinging tentacles of the Portuguese Man o’ War. The Blanket Octopus also exhibits one of the most extreme examples of sexual dimorphism of any animal: males, at 2.4 cm (or smaller), are minute, while the females can exceed 2 m in length.
8. Vulcanoctopus hydrothermalis
photo ©Rob Mickens/AMNH
Common name: N/A
Vulcanoctopus is the only known cephalopod adapted to life in hostile hyrothermal vent environments. This little, and little-known, octopus lacks chromatophores (the specialized cells that give most octopuses the ability to change their color almost instantaneously) and pigment of any kind. Its eyes have greatly reduced functionality, perhaps even a complete loss of function, as they show no reaction to light when encountered in the wild. They are known to eat amphipods and have been observed hunting vent crabs.
So that was just a thin slice of the fascinating world of the octopus. If you want to learn more about these wonderful creatures, visit the Tree of Life web project, TONMO.com, or The Cephalopod Page.
The official ICAD calendar says that today is Squid Day, so I guess I better get Kraken!
OK, so this doesn’t have anything to do with Cthulhu Week, but I thought this story was cool enough to break protocol.
Paleontologists in the UK have discovered a fossilized cephalopod so well preserved that the creature’s ink sac was still intact. In fact, scientists were able to extract a portion of the ink and use it to draw a picture of what the creature looked like when alive!
The 150 million year old fossil of Belemnotheutis antiquus was found in a recently rediscovered dig site in north Wiltshire that was first excavated during Victorian times. The excavation was lead by Dr. Phil Wilby, and was sponsored by the British Geological Survey and the Curry Fund.
B. antiquus was a belemnite, an extinct form of cephalopod closely related to modern squid and cuttlefish. Belemnites were abundant during the later part of the Mesozoic Era, but they went extinct at the end of the Cretaceous period. They resembled living squids, although they had ten hook-lined arms of equal length (no feeding tentacles) and an internal shell which protected the rear portions of the animial. This “guard” is usually the only part of a belemnite to become fossilized.
From NBC Bay Area via Pharyngula
The Humboldt Squid (Dosidicus giga) is a large predatory squid found all along the Pacific coast of North America. Also known as the Jumbo Squid, the Jumbo Flying Squid, and the Red Devil, Humboldts can grow up to 7 ft long and weigh as much as 100 lbs. They generally inhabit deep water, but come to the surface at night to feed. They can be very aggressive, and have reportedly attacked divers and fishermen.
Could a realatively minor earthquake (magnitude 4.0) really cause a school of squid to beach themselves? The experts seem to think it is just a coincidence, and point out that these type of strandings, while rare, have happened before.
Sepiadarium austrinum
[Image originally published in Cephalopods: A World Guide by Mark Norman.]
PZ Myer’s Pharyngula is a blog about evolution, development, and a myriad other aspects of the biological sciences. Myer is a fellow cephalopod enthusiast, and every Friday he posts an image of a cephalopod (such as the one shown above, from today) as part of a feature called, oddly enough, Friday Cephalopod.
Pharyngula is a member of the ScienceBlogs family, the source of many of the subscriptions in my blog reader.
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