Biología, Botánica, Genética y Zoología
DOLPHINS (Delphinus delphis)
Some animals almost humans. The dolphins and the people have always carried off well for many motives. One of them is that these animals have many empathy with the human beings because they possess personality, character and state of spirit. Also provides cerebral, which allows them of a tall capacity to remember acts, react to stimuli and learn conducts. They correspond through of vocalizations and of waves sound of ultrasound. Generally, the dolphins move parallel to the coasts where they exist readiness of fishing and squids and there are an adequate temperature. These animals have their own social hierarchy, that is defined for a leader. They are accustomed to move in groups, in those that the males go in outside, and the females and the breedings in the medium. They are very curious with the craft, to those that in many occasions accompany during hours. The small are, clearing, the most playful. In order to help it to be born, a nurse is placed below the mother and receives and they impel up to the breeding so that they breathe. The period of gestation is of 12 months and could come to live 40 years. Their predator more common is the killer whale and the sharks, although a great dolphins could come to gobble to a shark.
Longitude of the body 180-260cm, peso 75-115kg. Slender Morphology. Thin muzzle. The inferior mandible carries each half 33-67 teeth conic, generally between 40 50. The mandibles stand out under the forehead very marked: view of side, the superior mandible seems more narrow than the inferior. On the flattened loin and more or less to the half of the body, it has a dorsal fin round-triangular whose I carry to an extreme is lightly guided back. The fins pectorals is long and narrow. They below the eye begin some lateral clear strips to gray that discern back and they stand out the dark loin clearly when the dolphin jumps the water outside of. The color of the back oscillates between brown dark and black..
Extended for all the world in the marine tropical zones, subtropical and temperate; in the European coasts their abundance diminishes of south to north, but it in occasions arrive until the north of Scandinavia with the current of the gulf. It is not odd in the Mediterranean neither in the Black sea. On the other hand scare many in the Baltic, although it support the water salt perfectly. Coinciding with the old abundance of foods, the dolphins only appear in great number in waters coastal.
Alimentación y costumbres:
It feed of fish, squids and cuttlefish. It is a speedy swimmer, of the who it is said that it come to reach the 25 knots, it has customs gregarious, they live in flowing. The common dolphin is the better example of the adequacy of the morphology of the mammals to the conditions of aquatic life, adopting a form of fish.
More there of the waters of national jurisdiction, it follows carrying out other types of fishing. Maybe the most important and lucrative of all they are the fishing of tuna in tall sea, practiced in all the big oceans to exception of the Artic and the Antarctic.
You float them could employ ships endowed of advancing systems of nets of bag with the that capture to the tuna destined the markets preservers, or also those other ships with big apparels of nets of wiring. You float them with nets of bag that fish in the Oriental Pacific has occasioned especially grave damages in the ecosystems sailors, they since their captures are more abundant when the tuna meets banks of dolphins next to.
Those nets of bag rush from the ships on a bank of fish, when they join the ends of the net the same net they close below the fish. And although the relationship not to be acquainted with ecological between the tuna and the dolphins when they rush one of those nets with regard to a bank of dolphins with frequency is gotten a great number of tuna. In spite of a series of technical improvements, the nets of bag follow killing a great number of dolphins.
In the last years, the act more worriedly has been the increase of the fishing of haulage with big nets of wiring that the 50 km arrives even. Those nets kill to numerous species- included the marine mammals- without no courage for the fishermen. The reach of this type of fishing is truly impressive. They are calculated that some 7.000 kilometers of nets fish every year in waters of the Pacific.
In December of 1989, the General Assembly of United Nations approved a resolution for the who, starting from July 1 of 1991, they remain forbidden the fishing of haulage in the oceans. They exist, then, motives for the hope of the dolphins.
Without a doubt, one must fight determinedly so that they are prohibited the many in everybody "prisons of dolphins," in those that the people pay by seeing the acrobatics of these marvelous aquatics mammals.
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