Fish Hatchery Management - fisheries & aquaculture

342 FISH HATCHERY MANAGEM EN.Tshould be slit if the fish are larger than fingerlings. It also is desirable tocut the skin along the back of the fish. If the fish are larger than 6 inches,the cranial cap should be opened to facilitate fixation of the brain. Theimportance of these incisions cannot be overemphasized. If the fish are toolarge to ship whole, cut pieces from individual tissues (gill, heart, liver,etc.), and especially any lesions observed. These pieces should not be largerthan one-half inch square and one-quarter inch thick.Commercial formalin (containing about 40% formaldehyde) also can beused for preserving specimens and should be mixed with nine parts of waterto make approximately a 10% formalin solution.Unless the lesions are very clear and obvious, always preserve severalhealthy specimens of the same size and age as the sick fish, and send themat the same time in a separate container. This important step often determineswhether or not the disease can be diagnosed.Fish Disease LeafletsThe Fish Disease Leaflet (FDL) series is issued by the United States Fishand Wildlife Service in order to meet the needs of hatchery personnel forspecific information on fish diseases. Each Fish Disease Leaflet treats a particulardisease or parasite, and gives a brief history of the disease, its etiology,clinical signs, diagnosis, geographic range, occurrence, and methods ofcontrol. As new information becomes available, the Fish Disease Leafletsare revised. They are distributed from the Library, National FisheriesCenter (Leetown), Route 3, Box 41, Kearneysville, West Virginia 25430. Inthe following list, leaflets that have been superseded by more recent onesare omitted.FDL-I.FDL-2.FDL-5FDL-6.FDL-9.FDL-13.Infectious pancreatic necrosis (tpN) of salmonid fishes. KenWolf. 1966. 4 p.Parasites of fresh water fish. II. Protozoa. 3. Ichthyophthirus mul'tifilis.Fred P. MeYer. 1974.5 P-Parasites of fresh water fish. IV. Miscellaneous. Parasites of catfishes.Fred P. Meyer. 1966. 7 P.Viral hemorrhagic septicemia of rainbow trout. Ken Wolf'1972.8 p.Approved procedure for determining absence of viral hemorrhagicsepticemia and whirling disease in certain fish and fishproducts. G. L. Hoffman, S. F. Snieszko, and Ken Wolf. 1970.7p.Lymphocystis disease of fish. Ken Wolf. 1968. 4 p.