Dolphin: Man’s Best Friend…of the Water
Dolphins are very interesting creatures. They are most unique in their anatomy, personality, and—arguably—in their intelligence. There are many stories and myths about these magnificent animals.
A dolphin’s body is very streamlined. It is shaped much like a “torpedo,” making it easy for the dolphin to glide through the water at great speeds (Patent 8). There are only four things breaking the streamlined shape of a dolphin: two pectoral fins, a dorsal fin, and a fluke (Familiar 183). Of course without these things, a dolphin could not move as swiftly or as gracefully if it only had a body like a tapering tube.
A dolphin’s nose isn’t below its eyes as in most mammals. The single nostril of a dolphin is located on the top of its head and is called a blowhole (Behrens 8,9). A dolphin can hold its breathe by closing this blowhole when going underwater. Dolphins can hold the blowhole shut for up to seven minutes (Patent 10).
A dolphin’s ears are just tiny holes behind the eye (Patent 8). One would think this means dolphins have horrible hearing. On the contrary, a dolphin’s hearing is excellent. It has to be, for they rely on a phenomenon known as echolocation.
Echolocation occurs when a dolphin emits sounds and uses the echoes that return to identify what, where, what material make-up, and how far away an object is. Dolphins
have select sounds that are used for their echolocation. These special sounds are called clicks. These clicks are made in rapid-paced click trains. Scientists have to use special equipment to hear just one of these clicks within the click train. The click train is initially low-pitched in order to extend its range, and as the dolphin comes closer to the object, it increases the pitch to get more detailed information about the certain object (Dolphin Acoustics par. 11).
Although dolphins depend on their ears for echolocation in water, most also have excellent eyesight. Dolphins can see items farther than one meter away while above water level, but something has to be nearer than one meter for the dolphin to see it under water (Dolphins Research par. 9). This is why it needs echolocation to move around under water.
A female dolphin can only have one offspring at a time. Ten to twelve months after the father and mother mate, a baby dolphin stays in the mother’s womb in order to develop. The tail is the first to come out when a baby dolphin is born. I assume God made it this way because the baby has to breathe as soon as the blowhole is exposed to water and it would need to be the last thing out. When the baby is completely born, the mother, and sometimes another female, will help the newborn to the surface for its first breathe of air (Patent 23).
The time from birth to death was forty-eight years for the oldest bottle-nosed dolphin (Dolphin Natural History par. 32). There are some disagreements about whether or not a dolphin’s life span is affected by captivity. Some say it is shortened by captivity, and yet there are others that say it lengthens a dolphin’s life span. Even the scientists that
believe a dolphin’s life span is shortened think it is worth it. By learning about this dolphin in captivity, they can help the species as a whole.
One species that is most familiar to us humans is the bottle-nosed dolphin. It lives in shallow waters closer to shore allowing us a better look and study. One can see its long, stout body jump gracefully out of the water just by standing on the edge of an ocean or bay shore. You may even be able to see the three different colorations over its body with the dark gray back, lighter sides, and pink or white belly. This dolphin can grow to be up to five feet in length with a definite beak protruding and smiling from its face (Familiar 70).
A dolphin that looks similar to the bottle-nosed dolphin is the spinner dolphin. A spinner dolphin also has a definite beak and three colorations on its body with a dark gray back, tan sides, and white belly. Its size is somewhat smaller, only getting to be about seven feet long when grown(Familiar 80).
Another dolphin, the common dolphin, is similar in shape—including the beak—as the former two. The coloration, however, is a bit different in pattern. The common dolphin has a darker—almost black—back with a cream to white chest. Instead of having the side color subtly fade and taper, there is a definite patch of tan or yellow on both sides of a common dolphin. Comparably, the common dolphin falls between the bottle-nosed dolphin and the spinner dolphin in size, growing to be about eight feet and six inches in its body length (Familiar 82).
The killer whale is larger than the former three dolphins discussed. It can be up to thirty feet long. I admit I didn’t know it was a dolphin. Its size and almost nonexistent
beak make it easy to mistake for a whale, which would also explain its name. Killer whales are also known as orcas. An orca’s coloration consists of only two colors: black and white. The white covers the bottom from the mouth to near the end of the body and a patch over the eyes. There are also white spots on the underside of an orca’s fluke. Scientists use these individually unique spots like fingerprints to identify different orcas. There is a slight patch of soft gray around the dorsal fin (Familiar 102).
Dolphins have been said to have human characteristics. From the stories I read, it would seem dolphins are very humane, even if not human-like. In all my sources, there was at least one story of how a dolphin helped a human and even other animals. Sometime between Creation and the Great Flood, God allowed the peace between man and beast to be severed. However, we are blessed to still have a God-given bond with these playful, friendly mammals of the seas.
Behrens, June. Dolphins! Chicago: Children’s Press, 1989.
Dolphin Acoustics. Dolphin Research Center. 10 October 1999
<http://www.dolphins.org/learn/lmm-dsnd.html>
Dolphin Research. Dolphin Institute. 30 October 1999
<http://www.dolphin-institute.com/research/dolphinres.html#DOLPHIN>
Familiar Marine Mammals North America. The Audubon Society Pocket Books. New
York: Alfred A. Knopf, Inc., 1990.
Patent, Dorothy Hinshaw. Dolphins and Porpoises. New York: Holiday House, 1987.
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