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total length at hatching was 0.24-0.25 inches. Total length of normal fry at swim-up was greatest at 68°F (0.34 inches), compared with 0.32 inches at 59°and 77°F. The incidence of deformed fry was highest (4 percent) at 59°F. Bonytail fry produced at Willow Beach in 1981 were reared at the Dexter NFHTC (Hamman 1982b). Spawning trials on 2 year-old bonytail were carried out in 1983 (Hamman 1985) when 24 females were spawned over a 4-week period using carp pituitary extract to induce ovulation. The fish ranged from 1.6-8 ounces with a mean weight of 4.5 ounces. Fecundity ranged from 1,015 to 10,384 eggs per fish with a mean of 4,677. Average number of eggs per pound of body weight varied from 5,076 to 29,935 with a mean of 17,283; egg viability averaged 67.5 percent. Eggs were hatched in Heath incubators at 70°F. Bonytail have been placed into ponds at Arizona State University Research Park as well as earthen tanks at the Buenos Aires National Wildlife Refuge, Arizona; these stockings were made for research purposes and to produce fish for stockings elsewhere (Marsh 1988). An additional refugium was established at Hassayampa River Preserve owned by the Nature Conservancy. In 1983, 10,000 fry were shipped to the California Department of Fish and Game, and approximately 2,000 of these fish were placed into a small golf course pond. The young survived and grew with an expanding population of nonnative mosquitofish and African cichlids (USFWS 1990a). Moreover, bonytail annually produce substantial year classes through natural spawning under pond conditions at Dexter NFHTC (USFWS 1990a). CRITICAL HABITAT DEFINITION OF CRITICAL HABITAT "Critical habitat," as defined in Section 3(5)(A) of the Act, means: (i) the specific areas within the geographical area occupied by the species at the time it is listed, on which are found those physical and biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protection; and (ii) specific areas outside the geographical area occupied by a species at the time it is listed upon a determination by the Secretary that such areas are essential for the conservation of the species. The term "conservation," as defined in Section 3(3) of the Act, means: the use of all methods and procedures which are necessary to bring any endangered species or threatened species to the point at which the measures provided pursuant to this Act are no longer necessary. Therefore, in the case of critical habitat, conservation represents the areas required to recover a species to the point of delisting (i.e., the species is recovered and is removed from the list of endangered and threatened species). In this context, critical habitat preserves 36