Dauphin

Article

July 3, 2022

Dauphin is an ambiguous vernacular name designating in French certain marine and river mammals belonging to the order of cetaceans.

Terminology

Etymology

The masculine noun "dolphin" (/do.ˈfɛ̃/) is derived, via a Vulgar Latin *dalphinus, from the Classical Latin delphinus, itself derived from the Greek δελφίς / delphís,,, perhaps itself- even from δελφὐς / delphús, “uterus” or cognate of delphax, the pig, which shares an analogous layer of fat. Old French daufin is attested in the middle of the 12th century: according to the computerized Trésor de la langue française, its earliest known occurrence is in a manuscript of the Roman d'Alexandre. "Dauphin" designates in French many toothed cetaceans (odontocètes) less than five meters in length generally endowed with a long rostrum even if the most familiar species of dolphins, the one found in majority in dolphinariums, is the bottlenose dolphin, whose name means “truncated nose” in Latin. The species concerned are: several species of the Delphinidae family which also includes killer whales; Delphinoids and freshwater dolphins living in the rivers of Asia or South America. Under the term dolphin, many very different species are grouped together. At the behavioral level as well as at the physical level, the generalities specific to all dolphins are common to all odontocetes, called “dolphins” or not. Some cetaceans are sometimes incorrectly called "dolphins", for example those with a short or barely existing rostrum such as the narwhal and the beluga, two animals larger than the classic dolphins, but especially the porpoises which are much smaller.

Common names and corresponding scientific names

Alphabetical list of common names or attested vernacular names of cetaceans called "dolphin". Note: some species have multiple names and as classifications are still changing, some scientific names may have another valid synonym. In bold, the species best known to French speakers.

Biology, behavior and ecology

The general characteristics of dolphins are those of Cetaceans, with differences for each species: see the detailed articles for more information, in particular on their physical constitution and their respective way of life.

Evolution

Like whales and other cetaceans, the ancestors of dolphins lost their hind legs about 35 million years ago. At the beginning of gestation, the dolphin embryo has four legs which develop and then the hind legs retract and disappear.

Anatomy

Biology

Like other cetaceans, their domed forehead contains the "melon", a cavity filled with diverticula of the respiratory system that communicate with each other through valves. It is by sending air from one diverticulum to another that they emit sound. To locate their prey, dolphins use their sonar. They direct the sounds they emit in the direction of their future victims, the sound ricochets and returns with a modified sound to the ear of the dolphin. The dolphin propels itself out of the water using its tail fin.

Meaning

The dolphin ear has specific adaptations to the marine environment. In humans, the middle ear functions as an impedance equalizer between the low impedance of the outside air and the high impedance of the cochlear fluid. In dolphins and other marine mammals, there is no great difference between the outdoor and indoor environments. Instead of sound passing through the outer ear to the middle ear, dolphins receive sound through the throat, from where it passes through a low-impedance fat-filled cavity to