About Them
The octopus is a cephalopod mollusc in the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms. Octopuses have no internal or external skeleton (although some species have a vestigal remnant of a shell inside their mantle,) allowing them to squeeze through tight places. Octopuses are among the most intelligent and behaviorally flexible of all invertebrates.
The octopus inhabits many diverse regions of the ocean, including coral reefs, pelagic waters, and the ocean floor. They have numerous strategies for defending themselves against predators, including the expulsion of ink, the use of camoflauge and deimatic displays, their ability to jet quickly through the water, and their ability to hide. An octopus trails its eight arms behind it as it swims. All octopuses are venomous, but only one species, the blue-ringed octopuses are known to be deadly to humans.
In the larger sense, there are around 300 recognized octopus species, which is over one-third of the total number of known cephalopod species. The term octopus may also be used to refer only to those creatures in the genus Octopus.
Physical Characteristics: The Blue-Ringed Octopus (BRO) is a very small organism, belonging to the family of Octopodidae. Like all octopi, they are soft-bodied organisms with eight arms or tentacles. It grows to a maximum length of 200mm when totally spread, and most are shorter than this. The octopus has a mass of 10-100g and is about the size of a golf ball. The BRO is normally dark brown to dark yellow in color but changes to a vivid yellow with bright blue rings when agitated (Blue Zoo, 200.
Habitat and Distribution: The BRO can be found in shallow reefs and tide pools from Japan to Australia, and can be found at depths ranging from 0 to 20 m (Caldwell, 2000).
Food and Feeding: The octopus has two poison glands that secrete tow types of poison into the saliva. One type of poison secreted is primarily effective against crabs, its primary food source, and the other is very toxic and is used against predators for defensive purposes. It is not yet known whether the octopus simply secretes saliva near prey, and waits for it to become incapacitated, or if it actually bites its prey. Once the prey is dead, the octopus begins consuming it with its powerful beak-like mouth (McConnell, 2000).
Development and Lifespan: The BRO hatches from eggs and is about the size of a pea at the start of its life. The octopus will quickly grow and mature until it reaches the average adult size, about equivalent to the size of a golf ball. The life expectancy of a Blue-ringed octopus is about 2 years (Caldwell, 2000; McConnell, 2000).
Behavior: according to a University of Michigan website , the blue-ringed octopus exhibits the typical octopus behavior in that is tends to live in crevices or holes, burrows as a way of gaining protection, and advertises its toxicity by changing to iridescent colors when aggravated. The octopus can commonly be found in shallow tide pools after storm, searching for crabs and bivalves.
Mating Habits
Mating begins when an interested male approaches and starts caressing the female with his modified arm, the hectocotylus. He then inserts the hectocotylus under the mantle of the female and the spermatophores are then released into the female’s oviduct. The female then lays ~100 eggs and guards them until they hatch ~50 days later. The mother dies soon after the eggs hatch because during the guarding of the eggs she is unable to eat.
