| DOLPHINS |
|
|
|
|
|
|
Dolphins are mammals, not fish. They are warm
blooded like man, and give birth to one baby called a calf at a time. At birth a
bottlenose dolphin calf is about 90-130 cms long and will grow to approx. 4
metres, living up to 40 years.They are highly sociable animals, living in pods
which are fairly fluid, with dolphins from other pods interacting with eachother
from time to time.
Their teeth are interlocking rows of conical pegs, suitable for holding slippery fish. They eat their fish whole, head first. In the wild an open mouth is a sign of aggression, as is head nodding. A sign of greater aggression is violent jaw clapping.
Dolphins breathe through their blowhole located at the top of their head. A dolphin may empty and refill its lungs in less than a fifth of a second. As the dolphin breathes the air leaves the blowhole at speeds of over 100mph. Complex nerve endings around the blowhole sense pressure changes so the dolphin knows exactly when the blowhole is in or nearing the air and can be opened. Water in a dolphin's blowhole will actually drown it so powerful muscles close the blowhole as it dives under the water again.
The dolphin's skin is completely smooth allowing the dolphin to move easily through the water, and also reduce heat loss. Their skin may bear rake marks from other dolphins teeth during play or mating, and can easily become badly sunburnt if they strand. Their bodies are very streamlined so they may swim at high speeds through the water, and an example of this is their ears. Dolphin's ears are barely noticeable marked only by a small hole just behind the eye. In a bottlenose dolphin the ear is about 5-6 cms behind the eye and only 2-3 mm in diameter.
Dolphins are able to dive to great depths, and also leap to great heights. They
may leap to avoid predators or to show how powerful they are to females at
mating time. Noisy splashing jumps may also be used to herd fish. Bottlenose
dolphins can dive to depths of over 1,640 ft (500m).
Rahul Home