However, rules for each of these classes of animals can be extrapolated from the biblical requirements. Mammals According to the Torah, land-dwelling animals that both chew the cud (ruminate) and have cloven hooves, are kosher. By these requirements, any land-dwelling animal that is kosher can only possibly be a mammal, but even then, permitted are only those mammals that are placentals and strictly herbivorous (not omnivores nor carnivores) that both ruminate and also have cloven hooves, such as bovines (cattle/cows, bison, buffalos, yak, etc.), sheep, goats, deer, antelope, and technically, also giraffes. Although the giraffe falls under the kosher category by its characteristics, it does not have a masorah (tradition) for its consumption by any Jewish community. All other mammals, land-dwelling or otherwise, are forbidden by the Torah, including "crawling creatures" such as mice, and flying mammals such as the various species of bats. Water-bound mammals, such as whales, dolphins, seals, and dugongs, are also not kosher as they do not have the characteristics required of kosher water-bound creatures which must have both fins and scales. Those land-dwelling mammals that have only one of the two characteristics of kosher land-dwellers (only ruminant or only cloven hooved) are impure and cannot be consumed. By default, therefore, not only are most land-dwelling mammals not kosher, but all land-dwelling non-mammals are also not kosher, including reptiles, amphibians, molluscs (including snails), etc. Among mammals that Leviticus cites explicitly as an example of unclean is the camel, because it ruminates but does not have a cloven hoof; the hyrax and the hare are also explicitly given as examples of being excluded as kosher on the same grounds. Quintessentially, the Torah explicitly declares the pig unclean, because it has cloven hooves but does not ruminate. Fish According to , anything that comes from the water ("in the seas, and in the rivers") that has both fins and scales may be eaten. By those requirements, kosher water creatures can only possibly be fish, but even then, permitted are only those fish that have both fins and scales. All other non-fish water creatures are, by default, also not kosher, including amphibians, crustaceans, molluscs, water-bound mammals, water-bound reptiles, etc. While there is nothing specifically mentioned in Jewish halakha requiring kosher fish having an endoskeleton ("inner skeleton") and gills (as opposed to lungs), every true fish that has both scales and fins by default also possesses an endoskeleton and gills.