Category Nature Science & Wildlife

The octopus is a unique animal. It is intelligent, and has a sharp vision and a devastating array of offensive organs for attacking the prey. It is a fast swimmer, too. These qualities make the octopus a supreme predator.

Octopuses vary a great deal in size; the smallest is about 5 cm long, while the largest species may grow to 5.4 metres in length and have an arm span of almost 9 metres! They inhabit various regions of the ocean, including coral reefs, open sea waters, and the seabed.

The body of an octopus is designed for hunting. Its skin cells have the ability to change colour with the help of which it camouflages near rocks and the coral reefs. Its tentacles have muscular discs that help it catch prey. The octopus usually ambushes its prey; when a suitable prey comes, it shoots out one of its eight long tentacles and traps it. It usually feeds on crabs, shrimps and lobsters though it can attack larger prey like sharks as well.

Picture Credit : Google

The crown-of-thorns starfish is a large starfish that preys upon hard, or stony coral polyps. It is the world’s second largest starfish and grows up to the size of one meter. It has venomous thorn-like spines that cover its upper surface, resembling the biblical crown of thorns, and that is how it got its name.

The crown-of-thorns starfish is a well-known coral predator. It eats coral prey by extruding the stomach out from its body, covering the corals. An individual starfish can consume up to 6 square metres of living coral reef per year. Its spines are somewhat flexible; they are used for locomotion and for defence from potential predators.

The crown-of-thorns starfish are an important part of the ecosystem in normal numbers on healthy coral reefs. If more than 30 crown-of-thorns starfish are found in a hectare, it is called an outbreak. Outbreaks have been known to cause serious harm to coral reefs in some areas.

As its name suggests, the giant otter is huge. Its body grows to a length of up to 1.7 metres, which is the longest of all the otters on Earth.

Giant otters are also known as river wolves. They live in freshwater rivers and streams which are usually affected by seasonal flooding. Fish makes up the majority of their diet. They hunt either alone or in groups. A giant otter eats two to four kilograms of food per day. Fish are supplemented by crustaceans, snakes, and other river creatures.

Giant otters are well adapted for the aquatic way of life. They have webbed feet, water-repellent fur to keep them dry and warm, and nostrils and ears that close in the water. They swim by propelling themselves with their powerful tails and flexing their long bodies.

Giant otters are active during the day. They also have the reputation of being the noisiest of all the otters; scientists have documented distinct vocalizations that indicate alarm, aggression, and reassurance.

Picture Credit : Google

Sea anemones are known for their beauty; with their spectacular white, green, blue or red patterns and circles of petal-like tentacles, sea anemones have the appearance of harmless underwater flowers. It is with this appearance that they manage to deceive a lot of marine creatures.

More than 1,000 sea anemone species are found throughout the world’s oceans at various depths in varying sizes- some are as small as half an inch, while others may grow up to a size of six feet! Warmer seas are home to the largest and most colourful sea anemones.

Sea anemones are close relatives of jellyfish and corals. They do not have a solid skeleton. Some species have adhesive-secreting structures and cover themselves with grains of sand, bits of shell, or other foreign objects. With their elastic bodies and venomous tentacles, they trap a range of marine creatures including small fish, shrimps and crabs.

Do you know what a siphonophore is? It is an animal made up of a colony of organisms working together. The Portuguese man-of-war is a colony of individual organisms called polyps. It is often mistaken for a jellyfish, but truth be told, it is a highly venomous open ocean predator. It typically feeds on small marine organisms, such as fish and plankton.

Each polyp that makes up a Portuguese man-of-war is intertwined with the others, has highly specialized functions and cannot survive without the others. The largest of the polyps is known as the float; it is a bag of secreted gas which keeps the colony afloat. There are also feeding polyps, which are small digestive bags, each with its own mouth.

Tentacle polyps are the ones that look like elongated threads below the float and are studded with stinging cells. They have numerous venomous microscopic nematocysts which deliver a painful sting powerful enough to kill fish. They use the sting against predators as well. Apart from these, there are reproductive individuals as well.

Sea otters inhabit the Pacific coast. These sleek, furry marine mammals have no insulating layer of fat like other animals that live in colder climates, but are kept warm by their fur and high metabolism.

Sea otters were hunted for their fur to the point of near extinction. In fact, sea otters have the densest fur of any mammal; the coat of a sea otter has over half a million hairs per 6.5 square centimeters! These animals are very clean as well; they wash themselves after eating and frequently clean their fur with paws.

The way sea otters eat is interesting; they use their stomach as a table. A sea otter eats in the water, lying on its back, with its food on its chest. Sea otters are the only otters to give birth in the water. Mother sea otters have the ability to nurture their young while floating on their backs.

Sea otters play an instrumental role in controlling sea urchin populations which would otherwise inflict extensive damage to kelp forest ecosystems (underwater forests).