Marine Biology

The Eating Habits of Octopuses

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"The Eating Habits of Octopuses"
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Like all cephalopods, octopuses are predators from the moment of birth.

As freshly-hatched larvae, they spend a period of time drifting among the plankton, where they stalk and eat mini-prey such as copepods and larval starfish or crabs. At this stage, the little octopuses are themselves vulnerable to predation from an assortment of bigger predators.

Those who survive this dicey childhood sink to the seafloor. Here, armed with formidable intelligence for an invertebrate; exceptional eyesight; eight flexible, highly sensitive sucker-lined arms; and an ability to squeeze into the tightest of crevasses, the octopus is a stealthy and highly successful hunter.

The favored foods of octopuses include crabs, clams, whelks, and polychaete worms. An octopus uses its acute vision to spot prey and close in on it. It then grasps the prey animal with its arms, using its well-developed tactile sense to ensure that it has caught an appropriate food item. If the prey is acceptable, the octopus paralyses it with a toxic secretion from the parrot-like beak in the center of its arms. Nobody is entirely sure whether the octopus has to bite the animal to deliver this poison, or if the toxin is simply excreted into the surrounding water. In either case, the octopus' beak then goes into action, making short work of the shells. Its powerful arms also help to rip up some food items into bite-sized pieces. The chunks of meat are consumed, and the shells discarded.

An octopus can't swallow prey items whole, for a rather bizarre reason. Its esophagus passes right through the center of its donut-shaped brain.

Octopuses are amazing, alien creatures. They fascinate us because they are so very different from ourselves, yet intelligent and capable in their own unique way.

More about this author: Kallie Szczepanski

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