By: sepideh keshavarz. Introduction page1.
Dolphins are one of the smartest animals living in the ocean. There are about 40 species of dolphins. There are thirty-three ocean dolphins, five river dolphins, and six different kinds of porpoises. They have adapted to all of the oceans of the world. Dolphins are not fish; they are mammals. Dolphins' closest land relatives are pigs, cows, and deer! Dolphins evolved in the ocean, while hoofed animals evolved on land.
The biggest dolphin is the killer whale. Killer whale calves are about 8 feet long at birth and can grow to over 20 feet long. Bottlenose dolphins are about 3 1/2 feet long at birth and grow to 8 or 9 feet long.
The structure of dolphin groups (also called herds or pods) is more like that of elephants than humans. In killer whales the social group is formed by a female and her calves — even if they have grown to adults. The fathers of the calves do not live with the pod. We do not know what the social structure is for many kinds of dolphins.
, I’m this book author my name is sepideh keshavarz I am from IRAN student of Russell sage junior high school 190 in 7 grade . I like to write book for everyone to read and enjoy , I exertion to make this book , I am searching a lot in to the internet and I am study many book to find this information and I also use easy words to understand better, my aim of this are to show you what mammals are dolphin and I also show you body parts and other thing…..