342 KISH llAICHKRY MANAGEMENT 



should be slit if the fish are larger than fingerlings. It also is desirable to 

 cut 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. The 

 importance of these incisions cannot be overemphasized. If the fish are too 

 large to ship whole, cut pieces from individual tissues (gill, heart, liver, 

 etc.), and especially any lesions observed. These pieces should not be larger 

 than one-half inch square and one-quarter inch thick. 



Commercial formalin (containing about 40'^ formaldehyde) also can be 

 used for preserving specimens and should be mixed with nine parts of wa- 

 ter to make approximately a 10% formalin solution. 



Unless the lesions are very clear and obvious, always preserve several 

 healthy specimens of the same size and age as the sick fish, and send them 

 at the same time in a separate container. This important step often determines 

 whether or not the disease can be diagnosed. 



Fish Disease Leaflets 



The Fish Disease Leaflet (FDL) series is issued by the United States Fish 

 and Wildlife Service in order to meet the needs of hatchery personnel for 

 specific information on fish diseases. Each Fish Disease Leaflet treats a par- 

 ticular disease or parasite, and gives a brief history of the disease, its etiolo- 

 gy, clinical signs, diagnosis, geographic range, occurrence, and methods of 

 control. As new information becomes available, the Fish Disease Leaflets 

 are revised. They are distributed from the Library, National Fisheries 

 Center (Leetown), Route 3, Box 41, Kearneysville, West Virginia 25430. In 

 the following list, leaflets that have been superseded by more recent ones 

 are omitted. 



FDL-1. Infectious pancreatic necrosis (IPN) of salmonid fishes. Ken 

 Wolf. 1966. 4 p. 



FDL-2. Parasites of fresh water fish. II. Protozoa. 3. Ichthyophthirus mul- 

 tifilis. Fred P. Meyer. 1974. 5 p. 



FDL-5 Parasites of fresh water fish. IV. Miscellaneous. Parasites of cat- 



fishes. Fred P. Meyer. 1966. 7 p. 



FDL~6. Viral hemorrhagic septicemia of rainbow trout. Ken Wolf. 

 1972. 8 p. 



FDL-9. Approved procedure for determining absence of viral hemor- 

 rhagic septicemia and whirling disease in certain fish and fish 

 products. G. L. Hoffman, S. F. Snieszko, and Ken Wolf. 1970. 

 7 p. 



FDL-13. Lymphocystis disease offish. Ken Wolf. 1968. 4 p. 



