Bottlenose dolphins live in pods of typically 10-30 members but sometimes over 1,000. They communicate using sounds from their blowholes and bodies. Their diet consists mainly of forage fish, which they hunt individually or cooperatively by emitting echolocation clicks to locate prey.
Spinner dolphins primarily inhabit coastal waters and islands between 40 degrees north and south. They feed on small fish, squids, and shrimps by diving to depths of 200-300 meters. Off Hawaii, they forage cooperatively at night by herding prey into dense patches and making catches by swimming through.
2. The bottle nose Dolphin
BOTTLENOSE DOLPHINS LIVE IN GROUPS TYPICALLY OF 10–30
MEMBERS, CALLED PODS, BUT GROUP SIZE VARIES FROM SINGLE
INDIVIDUALS UP TO MORE THAN 1,000. THEIR DIETS CONSIST MAINLY OF
FORAGE FISH. DOLPHINS OFTEN WORK AS A TEAM TO HARVEST FISH
SCHOOLS, BUT THEY ALSO HUNT INDIVIDUALLY. DOLPHINS SEARCH FOR
PREY PRIMARILY USING ECHOLOCATION, WHICH IS SIMILAR TO SONAR.
THEY EMIT CLICKING SOUNDS AND LISTEN FOR THE RETURN ECHO'S TO
DETERMINE THE LOCATION AND SHAPE OF NEARBY ITEMS, INCLUDING
POTENTIAL PREY. BOTTLENOSE DOLPHINS ALSO USE SOUND FOR
COMMUNICATION, INCLUDING SQUEAKS AND WHISTLES EMITTED FROM
THE BLOWHOLE AND SOUNDS EMITTED THROUGH BODY
LANGUAGE, SUCH AS LEAPING FROM THE WATER AND SLAPPING THEIR
TAILS ON THE WATER SURFACE
3. THE SPINNER DOLPHIN
The spinner dolphin lives in nearly all tropical and subtropical
waters between 40°N and 40°S.The species primarily inhabits
coastal waters, islands, or banks. However, in the eastern
tropical Pacific, dolphins live far from shore. Spinner dolphin
may use different habitats depending on the season.
The spinner dolphin feeds mainly on
small mesopelagic fish, squids, and sergestid shrimps, and
will dive 200-300 m to feed on them. Spinner dolphins of
Hawaii are nocturnal feeder and forage in deep scattering
layers, which contain many species. The dwarf spinner
dolphin may eat mostly on benthic fish in reefs and shallow
water.[6] Off Oahu, Hawaii, spinner dolphins forage at night
and cooperatively herd their prey into highly dense
patches.[14] They swim around a circle of prey and a pair may
swim through it to make a catch. Spinner dolphins are in turn
preyed on by sharks. Other possible predators include the
killer whale, the false killer whale, the pygmy killer whale and
the short-finned pilot whale. They are also susceptible to
parasites, both external ones like barnacles and remoras, and
internal ones, like
nematodes, trematodes, cestodes and acanthocephalans.