by Roland D. Hallee

I saw an article recently in one of the local newspaper that fossils of an octopus were found in Montana, probably dated back before dinosaurs, some 330 million years. Let’s take a look at these denizens of the deep, at a creature we really don’t know that much about. We know what they look like, and some of what they do, but for what else would they be useful .

An octopus is a soft-bodied, eight-limbed mollusk. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviorally diverse of all invertebrates.

Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature early, and are short-lived. In most species, the male uses a specially adapted arm to deliver a bundle of sperm directly into the female’s mantle cavity, after which he becomes senescent and dies, while the female deposits fertilized eggs in a den and cares for them until they hatch, after which she also dies. Strategies to defend themselves against predators include the expulsion of ink, the use of camouflage and threat displays, the ability to jet quickly through the water and hide, and even deceit. All octopuses are venomous, but only the blue-ringed octopuses are known to be deadly to humans.

The giant Pacific octopus is often cited as the largest known octopus species. Adults usually weigh around 33 pounds, with an arm span of up to 14 feet.

The skin consists of a thin outer epidermis with mucous cells and sensory cells, and a connective tissue dermis consisting largely of collagen fibers and various cells allowing color change. Most of the body is made of soft tissue allowing it to lengthen, contract, and contort itself. The octopus can squeeze through tiny gaps. Lacking skeletal support, the arms work as muscular hydrostats and contain longitudinal, transverse and circular muscles around a central axial nerve. They can extend and contract, twist to left or right, bend at any place in any direction or be held rigid.

The ink sac of an octopus is located under the digestive gland. A gland attached to the sac produces the ink, and the sac stores it. The sac is close enough to the funnel for the octopus to shoot out the ink with a water jet. Before it leaves the funnel, the ink passes through glands which mix it with mucus, creating a thick, dark blob which allows the animal to escape from a predator.[61] The main pigment in the ink is melanin, which gives it its black color. Cirrate octopuses usually lack the ink sac.

The reproduction of octopuses has been studied in only a few species. One such species is the giant Pacific octopus, in which courtship is accompanied, especially in the male, by changes in skin texture and color. About 40 days after mating, the female giant Pacific octopus attaches strings of small fertilized eggs (10,000 to 70,000 in total) to rocks in a crevice or under an overhang. Here she guards and cares for them for about five months (160 days) until they hatch. In colder waters, such as those off Alaska, it may take up to ten months for the eggs to completely develop.

Octopuses have a relatively short lifespan; some species live for as little as six months. The Giant Pacific Octopus, one of the two largest species of octopus, may live for as much as five years. Octopus lifespan is limited by reproduction. For most octopuses the last stage of their life is called senescence. It is the breakdown of cellular function without repair or replacement. For males, this typically begins after mating. Senescence may last from weeks to a few months, at most. For females, it begins when they lay a clutch of eggs. Females will spend all their time aerating and protecting their eggs until they are ready to hatch. During senescence, an octopus does not feed and quickly weakens. Lesions begin to form and the octopus literally degenerates. Unable to defend themselves, octopuses often fall prey to predators. The larger Pacific striped octopus (LPSO) is an exception, as it can reproduce multiple times over a life of around two years.

Most species are solitary when not mating, though a few are known to occur in high densities and with frequent interactions, signaling, mate defending and eviction of individuals from dens. This is likely the result of abundant food supplies combined with limited den sites.

Nearly all octopuses are predatory; bottom-dwelling octopuses eat mainly crustaceans, worms, and other molluscs such as whelks and clams; open-ocean octopuses eat mainly prawns, fish and other cephalopods.

The octopuses evolved from the Muensterelloidea (fossil pictured) in the Jurassic period.

They evolved in the Cambrian some 530 million years ago. The earliest octopus likely lived near the sea floor in shallow marine environments. Since octopuses consist mostly of soft tissue, fossils are relatively rare. As soft-bodied cephalopods, they lack the external shell of most molluscs.

Octopuses appear in mythology as sea monsters like the Kraken, of Norway, and the Akkorokamui, of the Ainu, and probably the Gorgon, of ancient Greece. A battle with an octopus appears in Victor Hugo’s book Toilers of the Sea, inspiring other works such as Ian Fleming’s (creator of James Bond) Octopussy. Octopuses appear in Japanese erotic art, shunga. They are eaten and considered a delicacy by humans in many parts of the world, especially the Mediterranean and the Asian seas.

I once tasted calamari while in Vietnam, mostly as jerky – it was a little salty.

Historically, the first plural to commonly appear in English language sources, in the early 19th century, is the Latinate form “octopi”, followed by the English form “octopuses” in the latter half of the same century. The Hellenic plural is roughly contemporary in usage, although it is also the rarest. Oxford American Dictionary (3rd Edition, 2010) lists “octopuses” as the only acceptable pluralization, and indicates that “octopodes” is still occasionally used, but that “octopi” is incorrect.

Well, I hope we now know a little more about these creatures.

Roland’s trivia question of the week:

How many Boston Red Sox players have been named World Series MVP?

Answer can be found here.

by Roland D. Hallee

Last week we took a look at how white-tailed deer keep warm during those cold winter days and nights. As you remember, that was perpetrated by my watching birds at my wife’s feeders during the recent blizzard in early February. So, let’s talk about how those little feathered friends keep warm during those times.

First of all, I was astonished as I watched the birds come in and out of the feeders during the height of the storm, with winds gusting to 25-30 miles per hour.

Birds are warm-blooded animals that have a much higher temperature than humans, usually in the range of 105 degrees, as compared to our 98.6 degrees. Body temperatures can vary during daylight hours but it can challenge the birds during the night to maintain such a high body heat.

Smaller birds run more of a risk of body heat loss since they have a proportionately larger surface area on their bodies to lose heat but a smaller core volume to generate it.

Birds have different ways to maintain body heat during cold weather. Their feathers provide remarkable insulation, and many species will actually grow extra feathers as part of a late fall molt to give them thicker protection in the winter. Oil also coats their feathers to provide, not only insulation, but waterproofing.

Their legs and feet are covered with scales to minimize heat loss. By constricting blood flow to their extreminities, they can also reduce body heat loss even further.

Then, there is the old standby: adding body fat reserves to serve as insulation and extra energy for generating body heat. They will gorge themselves in the fall when food sources are abundant.

Another way to produce insulation from the cold is to fluff their feathers. That enables air pockets to be created, keeping them toasty warm. Also, it is not unusual to see birds standing on one leg or crouched to cover both legs with their feathers to shield them from the cold. They also tuck their beaks into their shoulder feathers for protection, and to breathe air warmed from their body heat.

On sunny days, they will perch with their backs to the sun to maximize the exposure area of their body. They raise their wings to allow the skin and feathers to absorb as much of the sun’s heat as possible, even spreading or drooping their wings while sunning.

If you see a bird shivering, don’t worry. They do this to raise their metabolic rate and generate more body heat as a short term solution in extreme cold.

Many small birds will gather in large flocks at night and crowd together in an attempt to share their collective body heat. Even individually, they will roost in places that may contain residual heat from the day’s sunlight.

But, there is something called torpor that birds will use to conserve energy during the cold nights. Torpor is a state of reduced metabolism when the body temperature is lowered, therefore requiring fewer calories to maintain the proper heat. Birds can lower their body temperature from 22 to 50 degrees. Torpor, however, can be dangerous as reduced temperature also leads to slower reactions and greater vulnerability to predators.

Even with all of these Mother Nature-built in safeguards, mortality rate among birds can run high during extreme winters. You can help.

During winter, keep your feeders cleared of snow and filled with good food, offer liquid water, and provide shelter. You can build brush piles or protective boxes if you have no natural shelters. I think one of the reasons we have as many birds during winter as we have is because birds are attracted to coniferous trees. My wife and I have three rather large pine trees in our backyard, providing them with plenty of protection from the weather.

Mother Nature, again, provides for its creatures, large or small.

Roland’s trivia question of the week:

Which current NFL team was originally called the New York Titans?

Answer can be found here.