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Porbeagle
The porbeagle or porbeagle shark (''Lamna nasus'') is a species of mackerel shark in the family Lamnidae, distributed widely in the cold and temperate marine waters of the North Atlantic and Southern Hemisphere. In the North Pacific, its ecological equivalent is the closely related salmon shark (''L. ditropis''). It typically reaches in length and a weight of ; North Atlantic sharks grow larger than Southern Hemisphere sharks and differ in coloration and aspects of life history. Gray above and white below, the porbeagle has a very stout midsection that tapers towards the long, pointed snout and the narrow base of the tail. It has large pectoral and first dorsal fins, tiny pelvic, second dorsal, and anal fins, and a crescent-shaped caudal fin. The most distinctive features of this species are its three-cusped teeth, the white blotch at the aft base of its first dorsal fin, and the two pairs of lateral keels on its tail. The porbeagle is an opportunistic hunter that preys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Peduncle
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish (Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish (Chondrichthyes) and jawless fish (Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are predominantl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectoral Fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column, back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bone, bony spine (zoology), spines or ray (fish fin anatomy), rays covered by a thin stretch of fish scale, scaleless skin; in lobe-finned fish (Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central limb bud, bud supported by appendicular skeleton, jointed bones; in cartilaginous fish (Chondrichthyes) and jawless fish (Agnatha), fins are fleshy "flipper (anatomy), flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamniformes
The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order (biology), order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the great white shark, great white as well as less familiar ones, such as the goblin shark and megamouth shark. Members of the order are distinguished by possessing two dorsal fins, an anal fin, five gill, gill slits, eyes without nictitating membranes, and a mouth extending behind the eyes. Species in two families of Lamniformes – Lamnidae and Alopiidae – are distinguished for maintaining a higher body temperature than the surrounding waters. Members of the group include Macro-predator, macropredators, generally of medium-large size, including the largest macropredatory shark ever, the extinct ''Otodus megalodon,'' as well as large planktivores. Although some authors have argued that the Late Jurassic ''Palaeocarcharias'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamnidae
The Lamnidae are the family of mackerel sharks known as white sharks. They are large, fast-swimming predatory fish found in oceans worldwide, though they prefer environments with colder water. The name of the family is formed from the Greek word ''lamna'', which means "fish of prey", and was derived from the Greek legendary creature, the Lamia.: ''A source-book of biological names and terms'', 1944, Edmund Carroll Jaeger These sharks have pointed snouts, spindle-shaped bodies, and large gill openings. The first dorsal fin is large, high, stiff and angular or somewhat rounded. The second dorsal and anal fins are minute. The caudal peduncle has a couple of less distinct keels. The teeth are gigantic. The fifth gill opening is in front of the pectoral fin and spiracles are sometimes absent. They are powerful, heavily built sharks, sometimes weighing nearly twice as much as other sharks of comparable length from other families. Many sharks in the family are among the fastest-swim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish (Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish (Chondrichthyes) and jawless fish (Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are predominan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Fin
Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only by muscles. Fish fins are distinctive anatomical features with varying structures among different clades: in ray-finned fish (Actinopterygii), fins are mainly composed of bony spines or rays covered by a thin stretch of scaleless skin; in lobe-finned fish ( Sarcopterygii) such as coelacanths and lungfish, fins are short rays based around a muscular central bud supported by jointed bones; in cartilaginous fish ( Chondrichthyes) and jawless fish ( Agnatha), fins are fleshy " flippers" supported by a cartilaginous skeleton. Fins at different locations of the fish body serve different purposes, and are divided into two groups: the midsagittal ''unpaired fins'' and the more laterally located ''paired fins''. Unpaired fins are pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothermy
An endotherm (from Greek ἔνδον ''endon'' "within" and θέρμη ''thermē'' "heat") is an organism that maintains its body at a metabolically favorable temperature, largely by the use of heat released by its internal bodily functions instead of relying almost purely on ambient heat. Such internally generated heat is mainly an incidental product of the animal's routine metabolism, but under conditions of excessive cold or low activity an endotherm might apply special mechanisms adapted specifically to heat production. Examples include special-function muscular exertion such as shivering, and uncoupled oxidative metabolism, such as within brown adipose tissue. Only birds and mammals are considered truly endothermic groups of animals. However, Argentine black and white tegu, leatherback sea turtles, lamnid sharks, tuna and billfishes, cicadas, and winter moths are mesothermic. Unlike mammals and birds, some reptiles, particularly some species of python and tegu, possess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Play (activity)
Play is a range of Motivation#Intrinsic and extrinsic, intrinsically motivated activities done for recreation. Play is commonly associated with children and juvenile-level activities, but may be engaged in at any life stage, and among other higher-functioning animals as well, most notably mammals and birds. Play is often interpreted as frivolous; yet the player can be intently focused on their objective, particularly when play is structured and goal-oriented, as in a game. Accordingly, play can range from relaxed, free-spirited, spontaneous, and frivolous to planned or even compulsive. Play is not just a pastime activity; it has the potential to serve as an important tool in numerous aspects of daily life for adolescents, adults, and cognitively advanced non-human species (such as primates). Not only does play promote and aid in physical development (such as hand-eye coordination), but it also aids in cognitive development and social skills, and can even act as a stepping stone i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aplacental Viviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop inside eggs that remain in the mother's body until they are ready to hatch. The young of some ovoviviparous amphibians, such as ''Limnonectes larvaepartus'', are born as larvae, and undergo further metamorphosis outside the body of the mother. Members of genera ''Nectophrynoides'' and ''Eleutherodactylus'' bear froglets, not only the hatching, but all the most conspicuous metamorphosis, being completed inside the body of the mother before birth. Among insects that depend on opportunistic exploitation of transient food sources, such as many Sarcophagidae and other carrion flies, and species such as many Calliphoridae, that rely on fresh dung, and parasitoids such as tachinid flies that depend on entering the host as soon as possible, the embryos commonly deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oophagy
Oophagy ( ) or ovophagy, literally "egg eating", is the practice of embryos feeding on eggs produced by the ovary while still inside the mother's uterus. The word oophagy is formed from the classical Greek (, "egg") and classical Greek (, "to eat"). In contrast, adelphophagy is the cannibalism of a multi-celled embryo. Oophagy is thought to occur in all sharks in the order Lamniformes and has been recorded in the bigeye thresher (''Alopias superciliosus''), the pelagic thresher (''A. pelagicus''), the shortfin mako (''Isurus oxyrinchus'') and the porbeagle (''Lamna nasus'') among others. It also occurs in the tawny nurse shark (''Nebrius ferrugineus''), and in the family Pseudotriakidae. This practice may lead to larger embryos or prepare the embryo for a predatory lifestyle. There are variations in the extent of oophagy among the different shark species. The grey nurse shark (''Carcharias taurus'') practices intrauterine cannibalism, the first developed embryo consum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Joseph Bonnaterre
Abbé Pierre Joseph Bonnaterre (1752, Aveyron – 20 September 1804, Saint-Geniez-d'Olt) was a French zoology, zoologist who contributed sections on cetaceans, mammals, birds, reptiles, amphibians, fish, and insects to the ''Tableau encyclopédique et méthodique''. He is also notable as the first scientist to study the feral child Victor of Aveyron. Bonnaterre is credited with identifying about 25 new species of fish, and assembled illustrations of about 400 in his encyclopedia work. He was the first scientist to study Victor, the wild child of Aveyron, whose life inspired François Truffaut for his film ''The Wild Child''. Partial bibliography * ''Tableau encyclopédique et méthodique des trois règnes de la nature, dix-huitième partie, insectes.'' Agasse, Paris 1797. * ''Recueil de médecine vétérinaire ou Collection de mémoires d'instructions et de recettes sur les maladies des animaux domestiques.'' * ''Tableau encyclopédique et méthodique des trois règnes de la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Ocean
The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change. In a manner analogous to stratification in the Earth's atmosphere, the water column can be divided vertically into up to five different layers (illustrated in the diagram), with the number of layers depending on the depth of the water. Marine life is affected by bathymetry (underwater topography) such as the seafloor, shoreline, or a submarine seamount, as well as by proximity to the boundary between the ocean and the atmosphere at the ocean surface, which brings light for photosynthesis, predation from above, and wind stirri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
