Animal's Anatomy and Biology
Dolphins have torpedo shaped bodies with generally non-flexible
necks, limbs modified into flippers, non-existent external ear flaps, a
tail fin, and bulbous heads. Dolphin skulls have small eye orbits, long
snouts, and eyes placed on the sides of its head. Dolphins range in size
from the 1.7 metres (5.6 ft) long and 50 kilograms (110 lb) Maui's dolphin to the 9.5 metres (31 ft) and 10 metric tons (11 short tons) killer whale. Overall, however, they tend to be dwarfed by other Cetartiodactyls. Several species have female-biased sexual dimorphism, with the females being larger than the males.[34][35]
Dolphins have conical shape teeth, as opposed to their counterparts, porpoise's, spade-shaped teeth. These conical teeth are used to catch swift prey such as fish, squid or large mammals, such as seal.[35]
Breathing involves expelling stale air from their blowhole,
forming an upward, steamy spout, followed by inhaling fresh air into
the lungs, however this only occurs in the polar regions of the oceans.
Dolphins have rather small, unidentifiable spouts.[35][36]
All dolphins have a thick layer of blubber,
thickness varying on climate. This blubber can help with buoyancy,
protection to some extent as predators would have a hard time getting
through a thick layer of fat, and energy for leaner times; the primary
usage for blubber is insulation from the harsh climate. Calves,
generally, are born with a thin layer of blubber, which develops at
different paces depending on the habitat.[35][37]
Dolphins have a two-chambered stomach that is similar in structure to terrestrial carnivores. They have fundic and pyloric chambers.[38]
​
The largest dolphin species is the orca, or killer whale. Male orcas grow to about 25 feet in length and weigh about 19,000 pounds. Lifespan: Most dolphins live long lives. The bottlenose dolphin can live over 40 years, and the orca can live to be 70 or 80!
​
breathe in air through their blowhole. The blowhole is covered by a
muscular flap which provides a watertight seal. The flap opens during
contraction and closes during muscle relaxation. For them to be able to
breathe, they have to rise to the surface and breathe in the oxygen.
When a dolphin breaths in air it goes directly into their lungs,
exhaling and inhaling rarely takes more than 0.3 seconds and they take
about 2-3 breathes per minute on average. During each respiration a
dolphin exchanges 80% or more of its lung air.
When diving, the
dolphin reduces its request for oxygen. Their heart beats slower and the
amount of blood pumped around the body decreases. During a deep dive
only important organs such as the heart and brain get oxygen rich blood
flowing through them.
​
​