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''Galea'' is a genus of South American rodents of the family Caviidae. Four species are known, found in Argentina, Bolivia, Chile, Peru and Brazil. They are: * Brazilian yellow-toothed cavy (''G. flavidens'') * Muenster yellow-toothed cavy (''G. monasteriensis'') * Common yellow-toothed cavy (''G. musteloides'') * Spix's yellow-toothed cavy (''G. spixii'') ''Galea'' has until recently been considered to have only three species; the Muenster yellow-toothed cavy was only described in 2004. ''G. flavidens'' is monotypic and ''G. musteloides'' and ''G. spixii'' are polytypic. ''Galea'' is in the family Caviidae and its members are described as cavies; they have sometimes also been called "guinea pigs". Cavies are widespread throughout South America. The high diversity of habitats of different species is paralleled by a high diversity of social organizations. Species differences between habitats and reproduction may shed light on evolutionary history. ''Galea'' breeds at multiple times of year that are not strongly constrained by food availability or climate. The gestation period is 48 days and litter size is 2 to 4, both less than those of the guinea pig. Placental development in ''Galea'' is very similar to that of the guinea pig. ''Galea'' species usually have smaller body size but the relative sizes of their testes and epididymitis are twice those of ''Cavia'' species. In the majority of cases, the acrosomes of ''Galea'' sperm are smooth in outline, and only occasionally are degenerate forms present or are the acrosomes absent. In ''Galea'', the spermatozoa of the epididymis are always single-cell whereas those of ''Cavia'' are agglutinated in the form of rouleaux. ''Galea'' spermatozoa swim more slowly than those of ''Cavia''. While some ''Galea'' species are promiscuous – for example ''G. musteloides''polygynous behavior, which means that males are selected for aggression so that multiple matings will be prohibited. == References == 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Galea (genus)」の詳細全文を読む スポンサード リンク
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