Rivulus cylindraceus (溪鮰) is a species of ray-finned fishes in the family New World rivulines. They are associated with freshwater habitat. Individuals can grow to 5.5 cm.
Definition: 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).
Comment: "Large" is ambiguous. For details on "Large rivers" (e.g. the Mekong river) see http://worldwildlife.org/biomes/large-river-ecosystems This class will be replaced with a less ambiguous class.
Definition: length from the tip of the snout to the tip of the longer lobe of the caudal fin, usually measured with the lobes compressed along the midline. It is a straight-line measure, not measured over the curve of the body
Definition: 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/).