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Delphininae
Oceanic dolphins or Delphinidae are a widely distributed family of dolphins that live in the sea. Close to forty extant species are recognised. They include several big species whose common names contain "whale" rather than "dolphin", such as the Globicephalinae (round-headed whales including the orca and pilot whale). Delphinidae is a family within the superfamily Delphinoidea, which also includes the porpoises (Phocoenidae) and the Monodontidae (beluga whale and narwhal). River dolphins are relatives of the Delphinoidea. Oceanic dolphins range in size from the and Maui's dolphin to the and orca, the largest known dolphin. Several species exhibit sexual dimorphism; the males are larger than females. They have streamlined bodies and two limbs that are modified into flippers. Though not quite as flexible as seals, some dolphins can travel at speeds 29 km/h (18 mph) for short distances. Most delphinids primarily eat fish, along with a smaller number of squid and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Dolphin
The common dolphin (''Delphinus delphis'') is the most abundant cetacean in the world, with a global population of about six million. Despite this fact and its vernacular name, the common dolphin is not thought of as the archetypal dolphin, with that distinction belonging to the bottlenose dolphin due to its popular appearances in aquaria and the media. However, the common dolphin is often depicted in Ancient Greek and Roman art and culture, most notably in a mural painted by the Greek Minoan civilization. It is presently the only member of the genus ''Delphinus''. The common dolphin belongs to the subfamily Delphininae, making this dolphin closely related to the three different species of bottlenose dolphins, humpback dolphins, striped dolphins, spinner dolphins, clymene dolphin, spotted dolphins, fraser's dolphin and the tucuxi and guiana dolphin. The common dolphin was originally categorized into two different species (now thought to be ecotypes), the short-beaked common d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delphinoidea
Delphinoidea is the largest group of toothed whales with 66 genera in 6 families. The largest living member of the superfamily is the killer whale, which can reach 6 tons, while the smallest is the vaquita. Taxonomy Based on McGowen ''et al''., 2019 Superfamily Delphinoidea :Family † Albireonidae :::Genus '' Albireo'' :Family Delphinidae :: Subfamily Delphininae ::: Genus ''Delphinus'' ::: Genus '' Lagenodelphis'' ::: Genus '' Sotalia'' :::Genus '' Sousa'' ::: Genus ''Stenella'' ::: Genus ''Tursiops'' :: Subfamily Globicephalinae ::: Genus †'' Astadelphis'' ::: Genus '' Feresa'' ::: Genus '' Globicephala'' ::: Genus '' Grampus'' ::: Genus '' Orcaella'' ::: Genus '' Peponocephala'' ::: Genus '' Pseudorca'' ::: Genus '' Steno'' ::Subfamily Lissodelphininae ::: Genus '' Cephalorhynchus'' ::: Genus '' Lissodelphis'' :: Subfamily Orcininae ::: Genus †'' Arimidelphis'' ::: Genus †'' Eodelphinus'' ::: Genus †'' Hemisyntrachelus'' ::: Genus '' Orcinus'' :: Subfamily incert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottlenose Dolphin
Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common bottlenose dolphin (''Tursiops truncatus'') and the Indo-Pacific bottlenose dolphin (''Tursiops aduncus''). Others, like the Burrunan dolphin (''Tursiops (aduncus) australis''), may be alternately considered their own species or be subspecies of ''T. aduncus''. Bottlenose dolphins inhabit warm and temperate seas worldwide, being found everywhere except for the Arctic and Antarctic Circle regions. Their name derives from the Latin ''tursio'' (dolphin) and ''truncatus'' for their characteristic truncated teeth. Numerous investigations of bottlenose dolphin intelligence have been conducted, examining mimicry, use of artificial language, object categorization, and self-recognition. They can use tools (sponging; using marine sponges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globicephalinae
Globicephalinae is a subfamily of oceanic dolphins that includes the pilot whales (''Globicephala'' spp.), the pygmy killer whale (''Feresa attenuata''), the rough-toothed dolphin (''Steno bredanensis''), the false killer whale (''Pseudorca crassidens''), the melon-headed whale (''Peponocephala electra''), Risso's dolphin Risso's dolphin (''Grampus griseus'') is a dolphin, the only species of the genus ''Grampus''. Some of the closest related species to these dolphins include: pilot whales (''Globicephala'' spp.), pygmy killer whales (''Feresa attenuata''), melo ... (''Grampus griseus''), and the snubfin dolphins ('' Orcaella'' spp.). References Oceanic dolphins {{Whale-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific White-sided Dolphin
The Pacific white-sided dolphin (''Lagenorhynchus obliquidens''), also known as the hookfin porpoise, is an active dolphin found in the cool or temperate waters of the North Pacific Ocean. Taxonomy The Pacific white-sided dolphin was named by Smithsonian mammalogist Theodore Nicholas Gill in 1865. It is morphologically similar to the dusky dolphin, which is found in the South Pacific. Genetic analysis by Frank Cipriano suggests the two species diverged around two million years ago. Though traditionally placed in the genus ''Lagenorhynchus'', molecular analyses indicate they are closer to dolphins of the genus ''Cephalorhynchus'', in the Lissodelphininae subfamily, than to both the Atlantic white-sided dolphin and the White-beaked dolphin. It has therefore been proposed to move the Pacific white-sided dolphin to the resurrected genus ''Sagmatias'' together with other southern hemisphere ''Lagenorhyncus'' species (hourglass dolphin, Dusky dolphin and Peale's dolphin). However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harem (zoology)
A harem is an animal group consisting of one or two males, a number of females, and their offspring. The dominant male drives off other males and maintains the unity of the group. If present, the second male is subservient to the dominant male. As juvenile males grow, they leave the group and roam as solitary individuals or join bachelor herds. Females in the group may be inter-related. The dominant male mates with the females as they become sexually active and drives off competitors, until he is displaced by another male. In some species, incoming males that achieve dominant status may commit infanticide. For the male, the primary benefit of the harem system is obtaining exclusive access to a group of mature females. The females benefit from being in a stable social group and the associated benefits of grooming, predator avoidance and cooperative defense of territory. The disadvantages for the male are the energetic costs of gaining or defending a harem which may leave him with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Echolocation
Echolocation, also called bio sonar, is a biological sonar used by several animal species. Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation, foraging, and hunting in various environments. Echolocating animals include some mammals (most notably Laurasiatheria) and a few birds, especially some bat species and odontocetes (toothed whales and dolphins), but also in simpler forms in other groups such as shrews, and two cave-dwelling bird groups, the so-called cave swiftlets in the genus '' Aerodramus'' (formerly ''Collocalia'') and the unrelated oilbird ''Steatornis caripensis''. Early research The term ''echolocation'' was coined in 1938 by the American zoologist Donald Griffin, who, with Robert Galambos, first demonstrated the phenomenon in bats. As Griffin described in his book, the 18t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. The time interval of a gestation is called the ''gestation period''. In obstetrics, '' gestational age'' refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. Mammals In mammals, pregnancy begins when a zygote (fertilized ovum) implants in the female's uterus and ends once the fetus leaves the uterus during labor or an abortion (whether induced or spontaneous). Humans In humans, pregnancy can be defined clinically or biochemically. Clinically, pregnancy starts from first day of the mother's last period. Biochemically, pregnancy starts when a woman's human chorionic gonadotropin (hCG) le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blubber
Blubber is a thick layer of vascularized adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians. Description Lipid-rich, collagen fiber-laced blubber comprises the hypodermis and covers the whole body, except for parts of the appendages. It is strongly attached to the musculature and skeleton by highly organized, fan-shaped networks of tendons and ligaments, can comprise up to 50% of the body mass of some marine mammals during some points in their lives, and can range from thick in dolphins and smaller whales, to more than thick in some bigger whales, such as right and bowhead whales. However, this is not indicative of larger whales' ability to retain heat better, as the thickness of a whale's blubber does not significantly affect heat loss. More indicative of a whale's ability to retain heat is the water and lipid concentration in blubber, as water reduces heat-retaining capacities, and lipid increases them. Function Blubber is the prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Whale Dolphin
Right whale dolphins are cetaceans belonging to the genus ''Lissodelphis''. It contains the northern right whale dolphin (''Lissodelphis borealis'') and the southern right whale dolphin (''Lissodelphis peronii''). These cetaceans are predominantly black, white beneath, and some of the few without a dorsal fin or ridge. They are smaller members of the delphinid family, oceanic dolphins, and very slender. Despite scientists being long acquainted with the species (the Northern species was identified by Titian Peale in 1848 and the Southern by Bernard Germain de la Cépède in 1804), little is known about them in terms of life history and behaviour. Physical description Both species have slender bodies, small, pointed flippers and a small fluke. Conspicuously, neither species has a dorsal fin; nor do right whales and this may explain the dolphins' name. The northern right whale dolphin is the only dolphin in the Pacific with this property. Similarly, the Southern is the only fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species ( freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as " rough fish" (mainly US) and "coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolphin Drive Hunting
Dolphin drive hunting, also called dolphin drive fishing, is a method of hunting dolphins and occasionally other small cetaceans by driving them together with boats and then usually into a bay or onto a beach. Their escape is prevented by closing off the route to the open sea or ocean with boats and nets. Dolphins are hunted this way in several places around the world including the Solomon Islands, the Faroe Islands, Peru, and Japan which is the most well-known practitioner of the method. In large numbers dolphins are mostly hunted for their whale meat, meat; some end up in dolphinariums. Despite the controversial nature of the hunt resulting in international criticism, and the possible health risk that the often polluted meat causes, tens of thousands of dolphins are caught in drive hunts each year. By country Faroe Islands Whaling in the Faroe Islands takes the form of beaching and slaughtering long-finned pilot whales. It has been practiced since about the time of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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