Rearing of coregonid fishes (Coregonidae) in illuminated lake cages: I. Growth and survival of Coregonus lavaretus L. and Coregonus peled Gmel.

The paper presents the results of rearing whitefish (Coregonus lavaretus L.) and peled (Coregonus peled Gmel.) in illuminated lake cages during a period of 4 years. In 3 successive years about 97 kg of summer coregonid fry were produced during initial 2-month rearing. Whitefish fry reached a length of 30.0–49.5 mm and an average individual weight of 201 mg–1 g. Peled fry reached 31.0–38.3 mm in length and 300–370 mg in weight. Whitefish survival rates amounted successively to 72.6% in 1977, 51.4% in 1978, and 3.1% in 1979. Survival rates for peled were 57.8%, 63.1% and 6%, respectively. Fishes at the age of 1+ and 2+ years showed high mortalities. Their growth rate was slower than in wild populations, and they did not attain sexual maturity.