oceany: Oceanic dolphin

Evidence: 100 • authority: 72

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, which include the false killer whale 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 a grouping of at least three cetacean superfamilies which form a sister group to Delphinoidea. Oceanic dolphins range in size from the 1.7-metre-long (5 ft 7 in) and 50-kilogram (110…

Evidence: 90 • authority: 72

A dolphin is any one of the 40 extant species of aquatic mammal from the cetacean families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the brackish dolphins), and the probably extinct Lipotidae (baiji or Chinese river dolphin). All these families belong to the parvorder Odontoceti, i.e., toothed whales, which also include the closely related families Monodontidae (beluga and narwhal) and Phocoenidae (porpoises), as well as the more distant families Physeteroidea (sperm whales) and Ziphiidae (beaked whales). Dolphins range in sizes from the human-sized 1.7-metre-long (5 ft 7 in) and 50-kilogram (110-pou…

Evidence: 35 • authority: 92

Behavioural responses of common dolphins to naval sonar.. Despite strong interest in how noise affects marine mammals, little is known for the most abundant and commonly exposed taxa. Social delphinids occur in groups of hundreds of individuals that travel quickly, change behaviour ephemerally and are not amenable to conventional tagging methods, posing challenges in quantifying noise impacts. We integrated drone-based photogrammetry, strategically placed acoustic recorders and broad-scale visual observations to provide complementary measurements of different aspects of behaviour for short- and long-beaked common dolphins. We measured behavioural responses during controlled exposure experim…

Evidence: 30 • authority: 72

The physiology of underwater diving is the physiological adaptations to diving of air-breathing vertebrates that have returned to the ocean from terrestrial lineages. They are a diverse group that include sea snakes, sea turtles, the marine iguana, saltwater crocodiles, penguins, pinnipeds, cetaceans, sea otters, manatees and dugongs. All known diving vertebrates dive to feed, and the extent of the diving in terms of depth and duration are influenced by feeding strategies, but also, in some cases, with predator avoidance. Diving behaviour is inextricably linked with the physiological adaptations for diving and often the behaviour leads to an investigation of the physiology that makes the be…

Evidence: 22 • authority: 72

Sharks are a group of elasmobranch cartilaginous fishes characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the division Selachii and are the sister group to the Batomorphi (rays and skates). Some sources extend the term "shark" as an informal category including extinct members of Chondrichthyes (cartilaginous fish) with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as Cladoselache and Doliodus first appeared in the Devonian Period (419–359 million years), though some fossilized chondrichthyan-like scales are as old as the Late Ord…

Evidence: 22 • authority: 88

Estimation of Operating Speeds at Road Humps on Short Street Sections with a 30 km/h Speed Limit. The application of traffic-calming measures (TCMs) constitutes an important preventive approach that improves road safety, particularly for vulnerable road users in urban environments. Due to economic considerations, the most commonly implemented measures are road humps (including speed humps, speed tables, and speed cushions), which significantly influence driver behaviour and contribute to speed reduction. Previous studies have demonstrated their considerable effectiveness; however, they remain limited and do not fully address certain important aspects, such as the relationship between speed…

Evidence: 22 • authority: 88

A chapter which, though short, may draw tears from some eyes. Mr Jones was just dressed to wait on Lady Bellaston, when Mrs Miller rapped at his door; and, being admitted, very earnestly desired his company below-stairs, to drink tea in the parlour. Upon his entrance into the room, she presently introduced a person to him,...