The ease with which dolphins(dauphins) adapt of the life in captivity allowed to approach searches(researches) which had been impracticable on free animals. Plusieurs Delphinidés so collaborates (because it is indeed about a real collaboration) with the scientists and the trainers. The most considerable are Tursiops, so much that the word "dolphin"("dauphin") evokes now, for the general public, graceful silhouette of this very nice animal. It is him that we mostly see evolving in "marinelands" and océanariums, where he(it) always takes away(gains) a big success with the spectators, who admire the ease with which he(it) executes varied exercises:sauter through a hoop, to seize delicately a fish which the trainer holds enter his(her,its) tooth, play with a balloon or different objects, etc. But we can quote also, among odontocètes become familiar, the globicéphale, the false killer whale, the Stenella, the Grampus (or dolphin(dauphin) of Risso), Steno, béluga, Lagenorhynchus, and even killer whale, who showed in captivity of the customs in contradiction with his(her,its) reputation of merciless murderer.

Since dozens of years, numerous works are dedicated to the general anatomy, the physiology, the biology, etc., Delphinidés, and particularly Tursiops. The most active nations in this domain are the United States, the U.R.S.S, and Japan. In France, it is necessary to indicate the laboratory of the I.N.R.A, steered by the professor R.G Busnel.

We can only summarize here the already acquired results, the very interesting results, certainly, but which have not ended in the solution of all the problems put by Cetaceans generally, and Odontocètes yet in particular. It is besides necessary to take into account because the behavior of a Cetacean in captivity can differ appreciably from that of the same animal in its natural environment(middle).

The ground is moreover very well prepared: he(it) is in the nature of free dolphins(dauphins) to play with floating objects which they are in the habit of pushing of the snout in front of them; and it is there doubtless the origin of their reputation of voluntary rescuers. They besides seem to try(feel) a big pleasure to learn and to repeat the tours(towers) of address which make the surprise and the admiration of the public.

It is the spectacular side of dolphins(dauphins) there. But the scientists, in narrow collaboration with the trainers, went much more far. They noticed first of all that dolphin(dauphin) pulled(entailed) in an aquarium could be put back(handed) in high tide and keep(preserve) all the capacities acquired by the training: obey the whistle or the voice(vote), and execute real missions. So, during the memorable experience(experiment) _ say "Sealab" _ organized by the American navy in 1965, dolphin(dauphin), named Tuffy, was used as vaguemestre and liaison officer between the divers, installed(settled) in their submarine houses, and the surface. Of are sides, the professor Perry W. Gilbert pursues very interesting experiences(experiments) on the use of Tursiops in the fight against the sharks. To the Mote Marine Laboratory, dolphin(dauphin), Simo, was gradually raised(gradually drawn up) to hunt(to chase away) and to attack(affect) a shark (in this particular case Carcharhinus milberti); The way she(he) fights(disputes) is simple and effective: he(it) strikes violently, with his(its) rostrum, the stomach of the shark, determining at this one of very grave internal hurts. It is not thus forbidden to think that we can one day use dolphins(dauphins) as guard dogs in the regions where the presence of sharks establishes(constitutes) a not unimportant danger. The study of the intelligence of dolphins(dauphins), and in particular Tursiops, holds attention at the same moment of anatomists and of psychophysiologistes. Comparisons were established between the weight absolved from the brain of various Mammals, what has no big sense(direction). Then we considered the report « weight brain - total weight ». Other researchers prefer to adopt the relation existing between the weight of the brain and the surface of the body of the animal.

No definitive conclusion can be again fired at present current studies in this domain. Certain authors admit that the brain of Tursiops is situated between that of the man and that of the monkey anthropoïde. However, an American observer, Scott Carpenter, asserts that a young Californian sea lion (Zalophus californianus) is capable of learning in some days what dolphin(dauphin) assimilates only after several months of training. Be that as it may, it is evident that dolphins(dauphins) possess a very developed brain, presenting numerous convolutions, and the anatomists agree to recognize that it is about intelligent beings.

In all the enigmae which have quickly just been reviewed adds the other one, stayed up to here absolutely without answer: how dolphins(dauphins) sleep t-ils? Contrary to it pass at the man's, where the breath is "automatic", that of dolphins(dauphins) (and of all the Cetaceans) is voluntary and requires(demands) on behalf of the animal an aware(conscious) and permanent effort. Dolphin(dauphin) placed under the influence of a narcotic stops breathing and does not delay dying. However, we noticed many a time that dolphins(dauphins) present the aspect of a rest, a relaxation which can persuade that the animal sleeps. It is can be that a sort of half-sleep, or an occasional sleep interrupted by short periods when the animal takes its breath. In any case, the problem remains composed.