Body
Fish have a variety of different body plans. Their body is divided into head, trunk, and tail, although the divisions are not always externally visible. The body is often fusiform, a streamlined body plan often found in fast-moving fish. They may also be filiform (eel-shaped) or vermiform (worm-shaped). Also, fish are often either compressed (laterally thin) or depressed (dorso-ventrally flat).
The caudal peduncle is the narrow part of the fish's body to which the caudal or tail fin is attached. The hypural joint is the joint between the caudal fin and the last of the vertebrae. The hypural is often fan-shaped.
Photophores are light-emitting organs which appears as luminous spots on some fishes. The light can be produced from compounds during the digestion of prey, from specialized mitochondrial cells in the organism called photocytes, or associated with symbiotic bacteria, and are used for attracting food or confusing predators.
The lateral line is a sense organ used to detect movement and vibration in the surrounding water. In most species, it consists of a line of receptors running along each side of the fish.
The ampullae of Lorenzini allow sharks to sense electrical discharges.
The genital papilla is a small, fleshy tube behind the anus in some fishes, from which the sperm or eggs are released; the sex of a fish often can be determined by the shape of its papilla.
Read more about this topic: Fish Anatomy
Famous quotes containing the word body:
“The will to change begins in the body not in the mind
My politics is in my body, accruing and expanding with every act of resistance and each of my failures.”
—Adrienne Rich (b. 1929)
“The elephant, not only the largest but the most intelligent of animals, provides us with an excellent example. It is faithful and tenderly loving to the female of its choice, mating only every third year and then for no more than five days, and so secretly as never to be seen, until, on the sixth day, it appears and goes at once to wash its whole body in the river, unwilling to return to the herd until thus purified. Such good and modest habits are an example to husband and wife.”
—St. Francis De Sales (1567–1622)
“Let us, then, take our compass; we are something, and we are not everything. The nature of our existence hides from us the knowledge of first beginnings which are born of the nothing; and the littleness of our being conceals from us the sight of the infinite. Our intellect holds the same position in the world of thought as our body occupies in the expanse of nature.”
—Blaise Pascal (1623–1662)