denise
08-12-2008, 04:32 PM
Whales are large, intelligent, air breathing, aquatic animals, the only mammals adapted to life in the open oceans. Like dolphins, they breathe air through blowhole(s) into their lungs (unlike fish who breathe using gills). The do not have to breathe for several minutes, and some whales can even stay submerged for two hours on a single breath! Because of their environment (unlike most animals), whales are conscious breathers: they decide when to breathe. When they sleep, they cannot fall into an unconscious state for too long, as they need to be conscious to breathe. It is believed that only one half of a whales brain sleeps at a time, so that they never completely fall asleep, but still get the rest they need. This is thought as whales usually sleep with only one eye closed!
Whales have sleek, streamlined bodies that move easily through the water. Their forelimbs, are modified into paddle shaped flippers. They have a layer of fat, called blubber, underneath their skin. Whales use this blubber layer for energy and insulation.
There are two different types of whales, baleen and toothed whales. The toothed whales (eg orcas), are predators that use their sharp teeth to catch fish, squid, and marine mammals, then swallow them whole. They have one blowhole, and use echolocation to hunt their prey. There are about 65 species of toothed whales. They travel in large, stable pods, hunting and migrating together.
Baleen whales (eg humpback and blue whales), have a large sieve like comb (composed of baleen plates), that they use to strain out tiny crustaceans and small fish from the water. Baleen whales are usually larger than the toothed whales and they all have 2 blowholes. There are 10 species of baleen whales. They travel alone or in small pods.
Unfortunately many large whales are now endangered as a result of intense commercial whaling over the last few centuries, for their oil, meat and baleen. By the middle of the 20th century, most population of large whales were severely depleted. In 1986, the International Whaling Commission introduced a ban on commercial whaling, which still exists. Certain exceptions to this rule exist, eg some small aboriginal communities of Siberia and Alaska, that depend on whales as sustinence for their small communities to survive. Some populations of whales are slowly increasing in numbers, but due to their slow reproductive rates, it will take a long time for populations to recover completely. Even if no whales were ever hunted again, they still face other serious threats, such as entanglements with fishing gear, pollution, and collisions with ships.
http://www.scubadiver.cc/fishid/orcarwhale.jpg
Orca or Killer Whale Orcinus orca, is found in every ocean in the world, from the freezing polar regions right down to warm, tropical seas. Orcas are versatile and opportunistic predators, they are also known as the wolves of the sea. Some populations feed mostly on fish, and other populations hunt marine mammals, such as seals, dolphins and even large whales. Scientists believe there are as many as up to five distinct different types of Orcas. Orcas are highly social animals, populations travel, hunt and live in large stable family groups. Unfortunately these beautiful animals are one of the most commonly kept aquarium animals.
http://www.scubadiver.cc/fishid/whalesharkfreedigitalphotos_1.jpg
Whale Shark, Rhincodon typus, the largest living fish species, is actually a filter feeding shark! They can grow to more than 40 feet in length and can weigh more than 15 tons! Whale sharks usually live in the open sea in warm tropical oceans, and can dive to depths of more than 2000 feet in their search for food!
http://www.scubadiver.cc/fishid/beluga.jpg
Beluga or White Whale, Delphinapterus leucas, is an Arctic and sub-Arctic water dwelling animal. They are very recognizable whale, having an all over white color, and a large melon shaped head!! Like other whales they are highly sociable animals, and live in family groups. Belugas feed mainly on fish, squid, octopus and crabs. They feed on the seabed at depths of up to 1,000 feet, but they can easily dive to 2000 feet! Generally their feeding dives will last 3-5 minutes, but belugas can remain submerged for up to 20 minutes at a time!
Whales have sleek, streamlined bodies that move easily through the water. Their forelimbs, are modified into paddle shaped flippers. They have a layer of fat, called blubber, underneath their skin. Whales use this blubber layer for energy and insulation.
There are two different types of whales, baleen and toothed whales. The toothed whales (eg orcas), are predators that use their sharp teeth to catch fish, squid, and marine mammals, then swallow them whole. They have one blowhole, and use echolocation to hunt their prey. There are about 65 species of toothed whales. They travel in large, stable pods, hunting and migrating together.
Baleen whales (eg humpback and blue whales), have a large sieve like comb (composed of baleen plates), that they use to strain out tiny crustaceans and small fish from the water. Baleen whales are usually larger than the toothed whales and they all have 2 blowholes. There are 10 species of baleen whales. They travel alone or in small pods.
Unfortunately many large whales are now endangered as a result of intense commercial whaling over the last few centuries, for their oil, meat and baleen. By the middle of the 20th century, most population of large whales were severely depleted. In 1986, the International Whaling Commission introduced a ban on commercial whaling, which still exists. Certain exceptions to this rule exist, eg some small aboriginal communities of Siberia and Alaska, that depend on whales as sustinence for their small communities to survive. Some populations of whales are slowly increasing in numbers, but due to their slow reproductive rates, it will take a long time for populations to recover completely. Even if no whales were ever hunted again, they still face other serious threats, such as entanglements with fishing gear, pollution, and collisions with ships.
http://www.scubadiver.cc/fishid/orcarwhale.jpg
Orca or Killer Whale Orcinus orca, is found in every ocean in the world, from the freezing polar regions right down to warm, tropical seas. Orcas are versatile and opportunistic predators, they are also known as the wolves of the sea. Some populations feed mostly on fish, and other populations hunt marine mammals, such as seals, dolphins and even large whales. Scientists believe there are as many as up to five distinct different types of Orcas. Orcas are highly social animals, populations travel, hunt and live in large stable family groups. Unfortunately these beautiful animals are one of the most commonly kept aquarium animals.
http://www.scubadiver.cc/fishid/whalesharkfreedigitalphotos_1.jpg
Whale Shark, Rhincodon typus, the largest living fish species, is actually a filter feeding shark! They can grow to more than 40 feet in length and can weigh more than 15 tons! Whale sharks usually live in the open sea in warm tropical oceans, and can dive to depths of more than 2000 feet in their search for food!
http://www.scubadiver.cc/fishid/beluga.jpg
Beluga or White Whale, Delphinapterus leucas, is an Arctic and sub-Arctic water dwelling animal. They are very recognizable whale, having an all over white color, and a large melon shaped head!! Like other whales they are highly sociable animals, and live in family groups. Belugas feed mainly on fish, squid, octopus and crabs. They feed on the seabed at depths of up to 1,000 feet, but they can easily dive to 2000 feet! Generally their feeding dives will last 3-5 minutes, but belugas can remain submerged for up to 20 minutes at a time!