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Clithon Spinosum
''Clithon spinosum'' is a species of brackish water and freshwater snail with an operculum, a nerite. It is an aquatic gastropod mollusk in the family Neritidae, the nerites. Distribution Distribution of ''Clithon spinosum'' include Indo-Pacific and it ranges from New Guinea and south-eastern Asia and eastern Asia to Marquesas. It also occurs in Japan, New Georgia,Haynes A. (1990). "The numbers of freshwater gastropods on Pacific islands and the theory of island biogeography". ''Malacologia'' 31237248. Fiji and Tahiti and in French Polynesia including the following Society Islands: Tahiti, Mo'orea, Raiatea, Huahine.Myers M. J., Meyer C. P. & Resh V. H. (2000). "Neritid and thiarid gastropods from French Polynesian streams: how reproduction (sexual, parthenogenetic) and dispersal (active, passive) affect population structure". '' Freshwater Biology'' 44(3): 535–545. . Description There are always spines on its shell.Haynes A. (1988). "Notes on the stream neritids (Gastropoda ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphidromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear. Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are ''anadromous'', in which adult fish live in the sea and migrate into fresh water to spawn; and ''catadromous'', in which adult fish live in fresh water and migrate into salt water to spawn. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Movements are associated with ocean currents and with the availability of food in different areas at different times of year. The migratory movements ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dioecious
Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is biparental reproduction. Dioecy has costs, since only about half the population directly produces offspring. It is one method for excluding self-fertilization and promoting allogamy (outcrossing), and thus tends to reduce the expression of recessive deleterious mutations present in a population. Plants have several other methods of preventing self-fertilization including, for example, dichogamy, herkogamy, and self-incompatibility. Dioecy is a dimorphic sexual system, alongside gynodioecy and androdioecy. In zoology In zoology, dioecious species may be opposed to hermaphroditic species, meaning that an individual is either male or female, in which case the synonym gonochory is more often used. Most animal species are dioecious (gon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manual Of Conchology
George Washington Tryon Jr. (20 May 1838 – 5 February 1888) was an American malacologist who worked at the Academy of Natural Sciences in Philadelphia. Biography George Washington Tryon was the son of Edward K. Tryon and Adeline Savidt. In 1853 he attended the Friends Central School in Philadelphia. In 1859, Tryon became a member of the Academy of Natural Sciences of Philadelphia. He was largely responsible for the construction of new buildings for the Academy, especially, in 1866, a section for malacology. In 1869 he became the conservator in this malacological section. In 1865, together with a group of American malacologists, he founded (and financed) the American Journal of Conchology. This ended in 1872. In 1879 he started the ''Manual of Conchology; structural and systematic; with illustrations of the species'', volume 1, series 1. When he died, nine volumes of the first series had been published. From 1887 until 1888, his assistant was Henry Augustus Pilsbry. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huahine
Huahine is an island located among the Society Islands, in French Polynesia, an overseas territory of France in the Pacific Ocean. It is part of the Leeward Islands group ''(Îles sous le Vent).'' At the 2017 census it had a population of 6,075.Répartition de la population en Polynésie française en 2017 Institut de la statistique de la Polynésie française History Human presence on Huahine dates back to ancient times, as evidenced by the numerous on the island. Archaeologists estimate that the ancient Tahitian Ma'ohi people colonized Huahine from at least the 9th century AD. Huahine is home to one of the largest concen ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raiatea
Raiatea or Ra'iatea ( Tahitian: ''Ra‘iātea'') is the second largest of the Society Islands, after Tahiti, in French Polynesia. The island is widely regarded as the "centre" of the eastern islands in ancient Polynesia and it is likely that the organised migrations to the Hawaiian Islands, New Zealand and other parts of East Polynesia started at Raiatea. A traditional name for the island is Havai'i, homeland of the Māori people. Situated on the southeast coast is the historical Taputapuatea marae, which was established by 1000 CE. The site was the political and religious center of eastern Polynesia for several centuries, and was inscribed on the UNESCO World Heritage List in 2017 for its historical significance. The main township on Raiatea is Uturoa, the administrative centre for the Leeward Islands (French ''Îles Sous-le-vent''). There are also colleges which serve as the main educational location for secondary schools for students from the regional islands of Bora Bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mo'orea
Moorea ( or ; Tahitian: ), also spelled Moorea, is a volcanic island in French Polynesia. It is one of the Windward Islands, a group that is part of the Society Islands, northwest of Tahiti. The name comes from the Tahitian word , meaning "yellow lizard": = lizard ; (from ) = yellow. An older name for the island is ', sometimes spelled or (among other spellings that were used by early visitors before Tahitian spelling was standardized). Early Western colonists and voyagers also referred to Moorea as ''York Island'' or ''Santo Domingo''. History Prehistory According to recent archaeological evidence, the Society Islands were probably settled from Samoa and Tonga around 200 CE.Patrick V. Kirch: ''On the Road of the Wind - An Archaeological History of the Pacific Islands Before European Contact'', University of California Press, Berkeley-Los Angeles-London 2000 Nine tribal principalities emerged in the enclosed valleys, which in turn were subdivided into individual cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tahiti
Tahiti (; Tahitian ; ; previously also known as Otaheite) is the largest island of the Windward group of the Society Islands in French Polynesia. It is located in the central part of the Pacific Ocean and the nearest major landmass is Australia. Divided into two parts, ''Tahiti Nui'' (bigger, northwestern part) and ''Tahiti Iti'' (smaller, southeastern part), the island was formed from volcanic activity; it is high and mountainous with surrounding coral reefs. Its population was 189,517 in 2017, making it by far the most populous island in French Polynesia and accounting for 68.7% of its total population. Tahiti is the economic, cultural and political centre of French Polynesia, an overseas collectivity and an overseas country of the French Republic. The capital of French Polynesia, Papeete, is located on the northwest coast of Tahiti. The only international airport in the region, Faaā International Airport, is on Tahiti near Papeete. Tahiti was originally settled by Pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Society Islands
The Society Islands (french: Îles de la Société, officially ''Archipel de la Société;'' ty, Tōtaiete mā) are an archipelago located in the South Pacific Ocean. Politically, they are part of French Polynesia, an overseas country of the French Republic. Geographically, they form part of Polynesia. The archipelago is believed to have been named by Captain James Cook during his first voyage in 1769, supposedly in honour of the Royal Society, the sponsor of the first British scientific survey of the islands; however, Cook wrote in his journal that he called the islands ''Society'' "as they lay contiguous to one another." History Dating colonization The first Polynesians are understood to have arrived on these islands around 1000AD. Oral history origin The islanders explain their origins in term of a orally transmitted story. The feathered god Ta'aroa lay in his shell. He called out but no-one answered, so he went back into his shell, where he stayed for aeons. When he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
