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Zalophus Californianus J
''Zalophus'' is a genus of the family Otariidae (sea lions and fur seals) of the order Carnivora. Description The seals of the genus ''Zalophus'' present a notorious sexual dimorphism, since the adult males have a pronounced sagittal crest, and weigh, in the Californian species, between 300 and 380 kg with 240 cm long, and the females 80 to 120 kg with between 180 and 200 cm. As with all ear seals, the males are significantly larger and heavier than the females. The males are dark brown in color, the females are lighter. In contrast to the other ear seals, the males do not have a clearly defined mane. In the Galapagos species the males weigh about 250 kg with a length of 250 to 270 cm, while the females weigh from 60 to 100 kg with a length of between 150 and 170 cm. They have a streamlined body, with a layer of fat under the skin, to provide warmth and buoyancy. The coat is brown. They have large eyes that help compensate for low light levels in the underwater environment, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodore Nicholas Gill
Theodore Nicholas Gill (March 21, 1837 – September 25, 1914) was an American ichthyologist, mammalogist, malacologist and librarian. Career Born and educated in New York City under private tutors, Gill early showed interest in natural history. He was associated with J. Carson Brevoort in the arrangement of the latter's entomological and ichthyological collections before going to Washington D.C. in 1863 to work at the Smithsonian Institution. He catalogued mammals, fishes and mollusks most particularly although maintaining proficiency in other orders of animals. He was librarian at the Smithsonian and also senior assistant to the Library of Congress. He was elected as a member of the American Philosophical Society in 1867. Gill was professor of zoology at George Washington University. He was also a member of the Megatherium Club at the Smithsonian Institution in Washington, D.C. Fellow members frequently mocked him for his vanity. He was president of the American Association ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California Sea Lion In La Jolla (70568)
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the most populated subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento is the state's capital, while Los Angeles is the most populous city in the state and the second most populous city in the country. San Francisco is the second most densely populated major city in the country. Los Angeles County is the country's most populous, while San Bernardino County is the largest county by area in the country. California borders Oregon to the north, Nevada and Arizona to the eas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zalophus
''Zalophus'' is a genus of the family Otariidae (sea lions and fur seals) of the order Carnivora. Description The seals of the genus ''Zalophus'' present a notorious sexual dimorphism, since the adult males have a pronounced sagittal crest, and weigh, in the Californian species, between 300 and 380 kg with 240 cm long, and the females 80 to 120 kg with between 180 and 200 cm. As with all ear seals, the males are significantly larger and heavier than the females. The males are dark brown in color, the females are lighter. In contrast to the other ear seals, the males do not have a clearly defined mane. In the Galapagos species the males weigh about 250 kg with a length of 250 to 270 cm, while the females weigh from 60 to 100 kg with a length of between 150 and 170 cm. They have a streamlined body, with a layer of fat under the skin, to provide warmth and buoyancy. The coat is brown. They have large eyes that help compensate for low light levels in the underwater environment, whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctocephalus
The genus ''Arctocephalus'' consists of the southern fur seals. ''Arctocephalus'' translates to "bear head." Taxonomy The number of species within the genus has been questioned, primarily based on limited molecular data. The issue is complicated because some of the species are able to produce fertile hybrids. A recent review recommended the retention of seven species, deprecating the New Zealand fur seals to a subspecies of the South American fur seal, while also questioning the status of the Guadalupe fur seal. Other recent studies have indicated the genus may be paraphyletic, and some taxonomic reshuffling was previously done to account for this; however, more recent studies support it being monophyletic, with the alleged paraphyly being a consequence of incomplete lineage sorting Incomplete lineage sorting, also termed hemiplasy, deep coalescence, retention of ancestral polymorphism, or trans-species polymorphism, describes a phenomenon in population genetics when ancestral ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japanese Sea Lion
The Japanese sea lion (''Zalophus japonicus'') ( ja, ニホンアシカ, translit=Nihon ashika, Korean:강치, 바다사자) was an aquatic mammal that became extinct in the 1970s. It was considered to be a subspecies of the related California sea lion (''Z. californianus'') until 2003. They inhabited the Sea of Japan, especially around the coastal areas of the Japanese Archipelago and the Korean Peninsula. They generally bred on sandy beaches which were open and flat, but sometimes in rocky areas. They were hunted commercially in the 1900s, leading to their extinction. Taxonomy Prior to 2003, it was considered to be a subspecies of California sea lion as ''Zalophus californianus japonicus''. However, it was subsequently reclassified as a separate species. DNA analysis in 2007 estimated that the divergence point between the two sea lions took place around 2 million years ago (mya) in the early Pleistocene. Several taxidermied specimens can be found in Japan and in the Nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galápagos Sea Lion
The Galápagos sea lion (''Zalophus wollebaeki'') is a species of sea lion that lives and breeds on the Galápagos Islands and, in smaller numbers, on Isla de la Plata (Ecuador). Being fairly social, they are often spotted sun-bathing on sandy shores or rock groups, or gliding through the surf. They are the smallest sea lion species. Taxonomy This species was first described by E. Sivertsen in 1953. It has been considered a subspecies of '' Zalophus californianus'' (called ''Z. c. wollebaeki'') by many authors. But recent genetic data supports ''Z. wollebaeki'' as a separate species. The species belongs to the family Otariidae and genus '' Zalophus''. Physical characteristics Slightly smaller than their Californian relatives, Galápagos sea lions range from in length and weigh between , with the males averaging larger than females. Adult males also tend to have a thicker, more robust neck, chest, and shoulders in comparison to their slender abdomen. Females, by contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excursion To A Lagoon On The N Side Of Isla Santa Fe - Galapagos Sea Lion (Zalophus Californianus) (16492679320)
An excursion is a trip by a group of people, usually made for leisure, education, or physical purposes. It is often an adjunct to a longer journey or visit to a place, sometimes for other (typically work-related) purposes. Public transportation companies issue reduced price excursion tickets to attract business of this type. Often these tickets are restricted to off-peak days or times for the destination concerned. Short excursions for education or for observations of natural phenomena are called field trips. One-day educational field studies are often made by classes as extracurricular exercises, e.g. to visit a natural or geographical feature. The term is also used for short military movements into foreign territory, without a formal announcement of war. See also * Business trip * Field trip * Picnic * Escorted tour Escorted tours are a form of tourism in which travelers are escorted in a group to various destinations, versus a self-guided tour where the tourist is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California Sea Lion
The California sea lion (''Zalophus californianus'') is a coastal eared seal native to western North America. It is one of six species of sea lions. Its natural habitat ranges from southeast Alaska to central Mexico, including the Gulf of California. California sea lions are sexually dimorphic; males are larger than females, and have a thicker neck, and a protruding sagittal crest. They mainly haul-out on sandy or rocky beaches, but they also frequent manmade environments such as marinas and wharves. California sea lions feed on a number of species of fish and squid, and are preyed on by orcas and great white sharks. California sea lions have a polygynous breeding pattern. From May to August, males establish territories and try to attract females with which to mate. Females are free to move in between territories, and are not coerced by males. Mothers nurse their pups in between foraging trips. California sea lions communicate with numerous vocalizations, notably with ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds ( taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otaria Californiana
The California sea lion (''Zalophus californianus'') is a coastal eared seal native to western North America. It is one of six species of sea lions. Its natural habitat ranges from southeast Alaska to central Mexico, including the Gulf of California. California sea lions are sexually dimorphic; males are larger than females, and have a thicker neck, and a protruding sagittal crest. They mainly haul-out on sandy or rocky beaches, but they also frequent manmade environments such as marinas and wharves. California sea lions feed on a number of species of fish and squid, and are preyed on by orcas and great white sharks. California sea lions have a polygynous breeding pattern. From May to August, males establish territories and try to attract females with which to mate. Females are free to move in between territories, and are not coerced by males. Mothers nurse their pups in between foraging trips. California sea lions communicate with numerous vocalizations, notably with barks and m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can reproduction, produce Fertility, fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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