定义：a thin membranous, sometimes alveolated sac in the dorsal portion of the abdominal cavity. Contains a varying mixture of gases, not identical to the composition of air.
定义：A taxon is Critically Endangered when the best available evidence indicates that it meets \r\nany of the criteria A to E for Critically Endangered, and it is therefore considered to be facing an extremely high risk of extinction in the wild
定义：A habitat that is in or on a body of water containing low concentrations of dissolved salts and other total dissolved solids (<0.5 grams dissolved salts per litre).
定义：Component found in mineralized skeletal tissue, (a specialized form of biogenic tissue in which the extracellular matrix is mineralized, and which functions in mechanical and structural support.)
定义：Capable of creating a new organism by combining the genetic material of two gametes, which may come from two parent organisms or from a single organism, in the case of self-fertilizing hermaphrodites.
定义：The institution that holds a type specimen for a given species. The recommended best practice is to use the identifier in a collections registry such as the Biodiversity Collections Index (http://www.biodiversitycollectionsindex.org/).
定义：Relative to pinhole eyes, lens eyes have greatly improved resolution and image brightness. The lens converges incoming rays of light, thereby reducing the angle over which each photoreceptor receives light, and forming an image focused on the retina. Most lens eyes have "accommodation"; they can focus an image either by physically moving the lens toward or away from the retina or by using eye muscles to adjust the shape of the lens.
