Creature Feature: Blanket Octopus

Referred to by some as the "Caped Crusader" or the "Batman" of the underwater world, the blanket octopus is a strangely beautiful creature. This fascinating cephalopod was given the common name of blanket octopus because of its flowing webbing connected between its dorsal and dorsolateral arms, resembling a large blanket, as displayed by this adult female. As you can see in this photo, its remaining arms are much shorter and lack webbing.

These octopi are classified in the pelagic cephalopod genus tremoctopus. They are further broken down into four species Gelatinous Blanket Octopus (tremoctopus gelatus), Palmate Octopus (tremoctopus gracilis), Common Blanket Octopus or Violet Blanket Octopus (tremoctopus violaceus), and Tremoctopus Robsoni. Sightings of these elusive creatures are rare, but they are known to have been found in the subtropical and tropical waters of the Mediterranean Sea and the Atlantic Ocean, and along the northern coast of Australia,  preferring surface to mid-water depths.

This cephalopod does not use ink to defend against predators as other octopi do. Instead, it uses its blanket to intimidate predators with its size. It has also been observed to display another defense mechanism. These particular octopi are immune to the deadly sting of the Portuguese Man 'o War jelly. The males and young females who lack the enormous blanket instead rip off the poisonous tentacles of a man 'o war and use them as a weapon against their would-be attacker.

The Blanket Octopus is an extreme example of sexual dimorphism. This term refers to the differences between the size and various physical characteristics of the male and female in the same species. "Imagine if your spouse was 40,000 times heavier and a hundred times larger than you. This is reality for the male blanket octopus..." [1] A male may grow up to approximately an inch in length, whereas an adult female can reach a length of 6.5 feet. The males have a specifically modified third tentacle which it fills with sperm. During mating the male rips of this tentacle, presents it to the female, then drifts away to die. The female then stores this tentacle inside a large internal body cavity until she is ready to lay up to 100,000 tiny eggs. Interestingly enough, females have been found with multiple tentacles stored in this cavity. When the female is ready to fertilize her eggs, she will pull out this stored tentacle and squeeze it "like a tube of toothpaste" over the eggs which she will then carry at the base of her dorsal arm until they hatch.

Below is a short, albeit cheezy, video showing the fascinating beauty of a female unfurling her blanket.

This second video shows another octopus calmly cruising the depths. Watch closely around 1:40 where it appears one of her banners disconnects. I could find no explanation for this, but she appears to continue on unfazed.

To see a picture of a male blanket octopus go to :

http://www.selfishgene.org/Tom/Papers/MDNetal_NZJFMR02.pdf [2]

[1] Pickrell, John (Aug. 12, 2003)."Walnut-Size" Male Octopus Seen Alive for First Time. National Geographic News.

[2] Norman, M.D.; Paul, D.; Finn, J.; and Tregenza, T. (2002). First encounter with a live male blanket octopus: the world's most sexually size-dimorphic large animal. New Zealand Journal of Marine and Freshwater Research 36: 733-736.

The Undersea World of Jacques Cousteau

The creative juices have seemed to slow down for my fellow contributors lately so rather than just writing another Creature Feature, I have been thinking long and hard about what to write that you all might find interesting. When I write my blogs it is always because it is a subject I want to know more about myself. I research it and then I like to share what I find with you.

So what to write about this week? Well, why not write about one of the great innovators of SCUBA, Mr. Jacques Cousteau. For us over 40 folks, the name is pretty familiar, but for the younger generations, maybe not so much. Being a child of the 60's, I remember sitting in front of the TV with our dinners on our TV trays watching such great shows with my family as the forever bubbly Lawrence Welk Show, Laugh In, Hee Haw, The Wonderful World of Disney, Mutual of Omaha's Wild Kingdom, and of course, The Undersea World of Jacques Cousteau.

Born June 11, 1910, Jacques Cousteau entered the École Navale (the French Naval Academy) in 1930 and graduated as a gunnery officer. Unfortunately (however fortunate for us) a car accident cut short his dreams of a a career in naval aviation, so during his time of rehabilitation from this accident he turned his interests to what lay under the sea. 

In 1936 Cousteau began his diving career with a pair of Fernez underwater goggles. (As a little side note, Maurice Fernez was a pioneer in the field of underwater breathing apparati. He was elemental in the transition from the tethered diving helmet of the 19th century to the invention of the self contained equipment of the 20th century.) The actual self contained underwater breathing apparatus (SCUBA) used by Jacques Cousteau in the 40's was invented by Commander Yves le Prieur in 1926. Dissatisfied with the length of time this unit allowed him to stay under water, Cousteau improved the design by adding a demand regulator invented by Émile Gagnan in 1942. In 1943 Cousteau tried out the first prototype aqua-lung which finally made extended underwater exploration possible and opened the door to the open-circuit scuba technology we use today. With that Cousteau embarked on a long career of ocean exploration and underwater film-making.

In the late 1940's, he took part on a small team assigned to explore the Roman wreck of Mahdia (Tunisia). It was the first underwater archaeology operation using autonomous diving, opening the way for scientific underwater archaeology. In 1950 Cousteau founded the French Oceanographic Campaigns and leased a ship called Calypso which he had refitted as a mobile laboratory for field research and the principal vessel for his diving and filming. For his 1956 film "Silent World", Cousteau, assisted by Jean Mollard, constructed the experimental underwater vehicle SP-350, the "diving saucer", which was able to transport the researcher to depths of 1150 feet. In 1965 Cousteau repeated his success with 2 more experimental vehicles which could now reach depths of 1640 feet.

To recite Jacques Cousteau's numerous achievements and accolades would take longer than this blog's depth. Suffice it to say, Cousteau influenced abundant changes in the perception of our oceans. Cousteau believed in sharing his scientific concepts with the world and regularly referred to himself as an "oceanographic technician". The legacy of his life's work includes more than 120 television documentaries, over 50 books, and an environmental protection foundation with an astounding membership of over 300,000 (http://cousteau.org/).

Jacques-Yves Cousteau died unexpectedly in Paris on June 25, 1997, at the age of 87. To this day, he is one of the most famous undersea explorers of the 20th century. If I have piqued your interest in this passionate visionary of the underwater world, you might find one of these other websites interesting:

http://www.biography.com/people/jacques-cousteau-9259496

http://news.nationalgeographic.com/news/2010/06/100611-jacques-cousteau-100th-anniversary-birthday-legacy-google/

Creature Feature: Rosy-lipped Batfish (Ogcocephalus porrectus)

By request, today I present you with the rosy-lipped batfish (scientific name: ogcocephalus porrectus). Found in the waters of Cocos Island off the coast of Costa Rica, this odd looking fish looks like it is ready for its "maybe it's Maybelline" close-up for smear-proof lipstick, but it definitely needs a shave.

This bottom-dwelling fish can be found at depths ranging from 90 to 450 feet. Seen from above, it has been said to resemble more of a "frog fish roadkill" than a bat. Full-grown it is about the size of your open hand, nearly flat on top, and spreads its pectoral fins out to its sides. A slow and clumsy character, the rosy-lipped batfish uses its pectoral and pelvic fins like legs to crawl on the ocean floor rather than swim. Ichthyologist and batfish expert John McCosker says they prefer to “sit upright, like old tail-dragging airplanes.”

It has a leathery skin that feels like sand paper and large spiny knobs covering its back. To add to its bizarre appearance, this fish has a unicorn-like horn protruding from its head. According to McCosker, this rostrum (a Latin word meaning "beak") is "firm - sort of like chicken gristle, and it protects a thin, retractable appendage that the batfish deploys to lure small edible fishes".

Ogcocephalus corniger is found in the waters of the southeastern
United States and the eastern Gulf of Mexico. 

Rosy-lipped batfish are voracious, carnivorous eaters who prefer a diet consisting mainly of small fish, shrimps, mollusks and crabs. An interesting x-ray of a close relative to the rosy-lipped batfish shows just what they enjoy eating. Another close relative is the red-lipped batfish, also called the Galapagos batfish (Ogcocephalus darwini), so aptly named for its choice of residence.

Why this drag-queen-looking fish looks like it does, I don't know if anyone really knows. I didn't find any answers in my research. But does the rosy-lipped batfish remind you of anyone in your family?