FEDER, H. M., C. H. TURNER, AND C. LlMBAUGH. 



1974. Observations on fishes associated with kelp beds in 

 southern California. Calif. Dep. Fish Game, Fish Bull. 

 160, 144 p. 

 HUBBS, C. L. 



1921. The ecology and life-history of Amphigonopterus au- 

 rora and other viviparous perches of California. Biol. 

 Bull. (Woods Hole) 40:181-209. 

 LAGIOS, M. D. 



1965. Seasonal changes in the cytology of the 

 adenohypophysis, testes, and ovaries of the black 

 surfperch, Embiotoca jacksoni, a viviparous percomorph 

 fish. Gen. Comp. Endocrinol. 5:207-221. 

 RECHNITZER, A. B., AND C. LlMBAUGH. 



1952. Breeding habits of Hyperprosopon argenteum, a vi- 

 viparous fish from California. Copeia 1952:41-42. 



Shaw, E., J. Allen, and R. Stone. 



1974. Notes on collection of shiner perch, Cymatogaster 

 aggregata in Bodega Harbor, California. Calif. Fish 

 Game 60:15-22. 

 TURNER, C. L. 



1938. Histological and cytological changes in the ovary of 

 Cymatogaster aggregatus during gestation. J. Morphol. 

 62:351-373. 

 WIEBE, J. P. 



1968. The reproductive cycle of the viviparous seaperch, 

 Cymatogaster aggregata Gibbons. Can. J. Zool. 

 46:1221-1234. 



Stephen R. Goldberg 

 William C. Ticknor, Jr. 



Department of Biology 

 Whittier College 

 Whittier, CA 90608 



GALLBLADDER LESIONS IN 

 CULTURED PACIFIC SALMON 



This note records observations on a previously un- 

 reported biliary lesion in the gallbladders of vari- 

 ous samples of coho, Oncorhynchus kisutch; 

 chinook, O. tshawytscha; and sockeye, O. nerka, 

 salmon cultured mainly in Puget Sound, Wash., 

 during 1974-76. There were no obvious signs of 

 distress or physical debilitation in affected fish. 

 The gallbladders were enlarged and impacted 

 with an amorphous yellow or white material 

 which, in some instances, extended into the com- 

 mon bile duct (Figure 1). 



Efforts to prove infectious origin were unsuc- 

 cessful. No bacteria were consistently isolated 

 from gallbladder or hepatic tissues and attempts 

 to demonstrate a viral agent on a chinook cell line 

 were negative. Possibilities of protozoan or hel- 

 minth parasitism were discounted after micro- 



scopic examination of tissues, gallbladder, and in- 

 testinal contents. 



Normal and impacted gallbladder, liver, and 

 kidney tissues were fixed in 10% buffered Forma- 

 lin 1 and stained sections were prepared at North- 

 west and Alaska Fisheries Center (NWAFC), 

 NMFS, NOAA, Seattle, Wash. Excessive vacuola- 

 tion of the columnar epithelium was evident in 

 affected gallbladders (Figure 2). No lesions were 

 observed in either the livers or kidneys offish with 

 the gallbladder condition. 



Preliminary studies (Table 1) indicate a pre- 

 dominance of an as yet uncharacterized 

 mucopolysaccharide material in impacted 

 gallbladders. Serum bilirubin, cholesterol, and 

 glucose concentrations of coho salmon with im- 

 pacted gallbladders were not different from those 

 found in normal fish. 



TABLE 1. — Composition of material in impacted gallbladders in 



coho salmon. 



Impacted gallbladders were first observed in 

 May 1974, when 25 yearling coho salmon from 

 saltwater pens in southern Puget Sound were re- 

 ferred to the disease laboratory at NWAFC 

 Aquaculture Experiment Station near Manches- 

 ter, Wash., for diagnosis of an unrelated skin in- 

 fection (Table 2). The condition was detected in 

 four separate lots of coho and chinook salmon in 

 central Puget Sound during the summer growing 

 season of 1974. In July 1975, the lesion was seen in 

 a subsample of 250 chinook salmon smolts in a 

 private freshwater rearing pond in Oregon (Table 

 2). Several lots of salmon being held for husbandry 

 and disease research at the Aquaculture Experi- 

 ment Station have also been found to have this 

 condition. 



Four thousand 0-age coho salmon smolts ( 18-20 

 g) reared on commercially prepared Oregon Moist 

 Pellets (OMP) were transferred to saltwater pens 

 at the Aquaculture Experiment Station in early 

 August 1976 where they continued to receive the 

 same ration. Smolts of the same stock (1,000) were 



1 Reference to trade names does not imply endorsement of the 

 National Marine Fisheries Service, NOAA. 



884 



