Dolphins are the cutest sea animals. They are very intelligent and learn things very quickly. Dolphins are not only cute but they are also very friendly creature. There are kept in many zoos and they perform aerobics to amuse kids. Below are given some interesting and informative facts about dolphin if you know little about them.
1. They are cetaceans
Dolphins belong to group of mammals called cetaceans. They belong to the teethed category of them. They are they toothed whales because they have cone shaped teeth. These are just to catch the prey not to eat the meal as we use our teeth for.
2. Dolphin is the diverse term
This term should not be taken as describing only one mammal of sea. It is a diverse term. In this category come the sea dolphins called dolphinidae, river dolphins called iniidae, and the Indian river dolphins called platanistidae. Oceanic dolphins are most diverse.
3. True Dolphins
It is the oceanic dolphins who are referred to as true dolphins because they are the most diverse. This subgroup includes 32 species of dolphins. They inhabit open sea waters as well as costal waters.
4. Their beak
Some dolphins have elongated jaw bones. This elongated jaw bone has numerous cone shaped teeth. Some species include as many as 130 teeth is one jaw. The dolphins that have long beak called rostrum include, sea dolphins, Atlantic hambpacked dolphins, and snouted spinner dolphins.
5. Pectoral flippers
The forelimbs of dolphins are called pectoral flippers. They are anatomically equivalent to to other mammals but with a difference that the bones of the forelimbs are shortened and made more rigid. They help dolphins to steer and modulate their speed.
6. Dorsal fin
The dorsal fin is located at the back of dolphin. It gives them control, direction and helps in swimming but not all the dolphins are blessed with this fin. The northern and the southern rightwhale dolphins lack dorsal fin.
7. Unique sense of hearing
Dolphins have unique sense of hearing. They do not have prominent ears but have ear slits behind their eyes. These slits do not directly attack to the middle ear but they are first attached to the fat-lobes located within the lower jaw but various bones.
8. Excellent vision
They can see in and out of the water without any difference. Outside water light reaches from sun to earth at same speed, but inside water the speed changes and a physical phenomena refraction occurs. To see inside water eyes must be adjusted to refraction as well. Dolphins has specialized cornea and lens for this.
9. Endangered Dolphin
Like all other beautiful creatures dolphins are also endangered. Baiji dolphins of the yangtze river in china has suffered a rampant population loss due to the use of yanstze river for industrial uses.
10. Poor sense of smell
Like all other teethed whales, dolphins too lack the sense of smell due to the necessary nerves not developed for this called olfactory sense.