Publications

No abstract available.

During the histological examination of a group of wild and hatchery salmonids undescribed sporazoans were frequently observed. This was not unexpected, since Myxosporidia are typical fish parasites (Kudo, 1920). Myxidium were observed in kidney tubules, Cholromyxum in glomeruli, and Myxobous in the spinal cord and on epidermal scales. The present paper will deal with the description and indentific

The anomalous condition of hermaphroditism appears to be no less rare in fish than in other normally dioecious animals. Previous records of bisexuality' in the Pacific salmons, Oncorhynchus spp., are few in number despite the intensive study accorded this group. Rutter (1902) reported the condition in two king salmon (O. tshawytscha); Crawford (1927) reported the condition in a silver salmon (O. k

The adult form of Triaenophorus crassus Forel, 1868 (= T. robustus Olsson, 1893; = T. tricuspidatus morpha megadentatus Wardle, 1932) occurs as an intestinal parasite in the pike, Esox lucius L., a holarctic species of wide distribution. Preliminary life-history stages include procercoid development in copepods of the genus Cyclops followed by plerocercoid development in the musculature of a varie

Disease, nutritional, and environmental problems in commercial production of trout are discussed, including mortality and age of spawners, copepod and gyrodactylid infections, suitable water temperatures, diseases (especially red mouth and back peel) and inspection of fish. It is concluded that experiences with hatchery procedures have varied greatly and often the commercial trout producer must ad

The salmon fishing industry of the Pacific Coast is dependent on the survival and propagation of 5 species of salmon which spawn in rivers of that portion of the North American continent extending from California to Alaska. The development of these rivers for power, irrigation, flood control and other projects has drastically reduced the natural spawning areas available to salmon. To prevent the e

Adverse effects from the medication of fish diseases with sulfonamides have been reported by several workers. A decreased growth rate (Gutsell and Snieszko 1949, Snieszko and Wood 1955), the production of drug resistant strains of pathogens (Snieszko 1952), sterility and kidney damage (Wood et al., 1955), and mortalities (Johnson and Brice 1953) have been described. Recently, increased mortalities

The body composition of salmonids raised in hatcheries is markedly different, both chemically and histologically, from that of wild fish (Wood et al., '57). Differences between arti ficial and natural diets were suggested as important causative factors. Several workers have compared specific hatchery diets to a wide array of wild organisms which form the com ponents of wild diets (Embody and Gordo

Possibly no single disease accounts for greater annual mortality than gill disease. Apparently endemic in many hatcheries, the disease is characterized by periodic sharp upsurges which are sometimes correlated with rising water temperatures, excessive foreign matter in the water (Wales and Evins 1937), or borderline nutritional conditions.

The major purpose of this publication is to present an annotated bibliography of papers resulting from Federal investigations on the Great Lakes fish and fisheries since the formal initiation of a continuing research program by the Fish and Wildlife Service. It is believed that this purpose can be served best by prefacing that bibliography with a brief account of the origins of Great Lakes Fishery

No abstract available.

No abstract available.