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The Ozark cavefish, ''Amblyopsis rosae'', is a small subterranean freshwater fish native to the United States. It has been listed as a threatened species in the US since 1984; the IUCN lists the species as Vulnerable. It is listed as endangered by the Missouri Department of Conservation.〔 Listed as Vulnerable (VU D1+2 v2.3) 〕 The Ozark cavefish is pinkish-white and reaches a maximum length of 2.0 in (5 cm). The head is flattened, and it has a slightly protruding lower jaw. The fish has no pelvic fin; the dorsal and anal fins are farther back than on most fish. It has only rudimentary eyes and no optic nerve. The Ozark cavefish lives only in caves. It has no pigmentation and has lost some unused characters. However, it is well adapted to a cave environment through well-developed sensory papillae. They feed primarily on microscopic organisms, as well as small crustaceans and salamander larvae. Their reproductive rate is low compared to most other fish.〔 〕〔 〕 ==Habitat== Caves which have populations of the Ozark cavefish all have a relatively large source of nutrients, such as bat guano or blown leaf litter. Water quality in caves containing them is usually high. They are able to tolerate the extremely low oxygen content of ground water found in caves. Cavefish tend to occur in flowing cave streams as opposed to quiet pools. The Ozark cavefish can receive nutrients from the tree roots above the cave. The roots are full of nutrients and water. The roots spread photosynthetic products in the cave, so organisms like Ozark cavefish and other species are able to feed on the roots. 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「Ozark cavefish」の詳細全文を読む スポンサード リンク
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