The study of the remains of fish on archaeological sites, in the form of bones, otoliths, and scales. The latter only survive occasionally in anaerobic conditions, while otoliths have not, to date, been frequently recorded. Fish have markedly different skeletons from mammals. Many fishbones are so small that they appear only in sieving and the bones commonly preserved are the jaws and some other head bones, and the vertebrae. They usually accumulate in refuse deposits and may be interpreted in terms of diet and fishing on the site or in the area that supplied it. Identification of species through comparison with modern fishbones is becoming easier as larger collections of comparative material are built up. When a species has been identified it can lead to evidence for the hydrological conditions around the site; also, the occurrence of the remains of marine species on an inland site has implications for the movement of groups or a trade in fish. A combination of species identification and aging of fish through study of the otoliths can lead to assumptions about the seasonal occupation of certain settlement sites and the subsistence economy of the associated groups.