The frequency, distribution, and pathology of three diseases of demersal fishes in the Bering Sea

• Published in: Journal of Fish Biology
• Main Authors: McCain, Bruce B., Myers, Mark S., Gronlund, William D., Wellings, S. R., Alpers, Charles E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1978
• Subjects: Bering Sea; Pacific
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1978.tb04172.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1978.tb04172.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1978.tb04172.x

During September and October, 1975, bottom‐dwelling fish from the Bering Sea were examined for diseases. The three most commonly observed diseases and their frequency of occurrence were epidermal papillomas of rock sole ( Lepidopsetta bilineata Ayres), 1‐0%; lymphocystis of yellowfln sole ( Limanda aspera Pallas), 2‐1 %; and epidermal tumours of the pseudobranch of adult Pacific cod ( Gadus macrocephalus Tilesius), 7‐4%. Both the appearance and the histological characteristics of epidermal papillomas on rock sole resembled those found on several species of flatfish in Puget Sound. The frequency of tumour‐bearing rock sole ranged from 0‐23%, with the highest occurrence at sampling stations around the periphery of the Bering Sea in water depths of 20‐30 fathoms (36‐54 m). The virus‐caused lymphocystis lesions were usually on the ‘blind’ side fins and skin surfaces of yellowfin sole, the largest lesions being found on the operculum, and the most common site of infection was the pectoral fin. The frequency of lymphocystis was 0‐15 %, with a gradual increase of prevalence from the northern to southern sampling stations. The Pacific cod tumours were always bilateral, and contained remnants of normal‐appearing pseudobranchial tissue on the surface or deep inside the tumours. Portions of some tumours were necrotic and liquefied. Tumour‐bearing cod were most commonly found in the south and south‐eastern Bering Sea and the frequency of affected cod ranged from 0‐100%.