Greens [2] ( Latin Globicephala ), or black dolphins , is a genus of mammals from the dolphin family, containing two species: the common grind ( Globicephala melas ) and the short fin grind ( Globicephala macrorhynchus ). The word grind comes from the Faroese language .
Greens |
Short grind ( Globicephala macrorhynchus ) |
Scientific classification |
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No rank : | Bilateral symmetric |
Nadotryad : | Laurasiotherium |
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International Scientific Name |
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Globicephala Lesson , 1828 |
Synonyms |
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- Cetus Wagler, 1830
- Globiceps Flower, 1884
- Sphaerocephalus Gray, 1864 [1]
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Kinds |
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( G. macrorhynchus ) - Common Grind ( G. melas )
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Area |
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Globicephala macrorhynchus Globicephala melas Both kinds |
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Content
The length of the grind varies from 3.6 to 8.5 meters, and their weight averages 800 kg (in some cases there are also specimens weighing up to 3000 kg). Their cylindrical body, the head is rounded, with a short snout, and barely stands out from the body. With the exception of the white spot under the chin, the greens are painted completely black. Both species differ from each other in the length of the fins , as well as in the number of teeth : in short-finned grind there are from fourteen to eighteen to the jaw, and in the ordinary grinda from sixteen to twenty-six. Killer whales and short-finned grindas are two of the few mammalian species (including humans) in which females go through menopause and live for many decades after they lose their ability to conceive [3] [4] .
Greens prefer the open sea and only occasionally occur off the coast. While the short-finned grind loves tropical and subtropical seas, the common grind lives more often in temperate and cool latitudes, including in Northern Europe .
Grinds sleep in the daytime, and at night they go in search of food. The duration of their diving is from five to ten minutes, during which they manage to descend to a depth of more than 600 m. Their food consists mainly of cephalopods and, to a lesser extent, of fish . There are cases of attacks on sperm whales [5] . Grinds live, as a rule, in groups of 20-30 individuals, although groups consisting of more than 100 individuals were observed. The group obeys the leader, the social behavior inside it is developed quite strongly.
There is at least one reliable case of the "attack" of the gird on a person (captured on video). On May 12, 1991, the male grabbed the diver Lisa Castello by the leg, sank with her to a depth of about 10 meters, and then gently raised her back. The woman got off with only a slightly stripped leg. In her opinion, the dolphin did not try to harm her. The contact was provoked by the people themselves, as the divers intentionally swam among the animals and touched them with their hands, which is not recommended to be done with any wild animals. Grinda repeatedly expressed dissatisfaction with the diver’s actions, flashing her tail on the water, and, in the absence of a response to the warnings, might have just taught her a lesson [6] .