is inquisitive, intelligent, and even capable of
learning human-taught language. Dolphins have been known
for saving human lives at sea and even make remarkable
therapy animals for the disabled.
Dolphins live in nearly every ocean and
sea, from the Arctic to Antarctica. There are 32 species
of marine dolphins and four kinds of river dolphins, and
each species has its own preferred habitat.
Dolphins eat all kinds of fish
(favorites are mackerel, herring, mullet, and cod),
squid, octupus, and crustaceans. An average size dolphin
will eat 30 to 50 pounds of food per day.
Dolphins are very social and live in
groups called pods. There is a hierarchy with males
dominant over females. When different groups meet, they
engage in a greeting ceremony; they leap, chase, and
touch each other, thus re-establishing social
relationships. Although dolphins can live individually,
groups can range from a few to 500 individuals.
Dolphins and porpoises are not the same
animal; in fact, they come from different whale
families. For one thing, they differ physically: Most
dolphins have a distinctive pointed beak whereas
porpoises have a more rounded beak. Also, dolphins have
hook-shaped dorsal fins, unlike the porpoises'
Dolphins cannot go into a deep sleep
because when unconscious, they forget to breathe and
would suffocate. A dolphin can only sleep by letting one
half of its brain sleep at a time.