SOME ASPECTS OF THE BIOLOGY OF THE ANADROMOUS POPULATION OF WHITEFISH (COREGONUS LAVARETUS LAVARETUS) FROM LAKE ŁEBSKO (NORTHERN POLAND)
Andrzej Martyniak*, Piotr Hliwa*, Jacek Kozłowski*, Bogdan Wziątek*, Tomasz Heese**, Marek Sobocki***
*University of Warmia and Mazury in Olsztyn, Poland
**Technical University of Koszalin, Poland
***Słowiński National Park, Smołdzino, Poland
ABSTRACT. The age structure and growth rate of a native population of whitefish, Coregonus lavaretus lavaretus L., were analyzed on the basis of 66 specimens. The fishes were caught in autumn-winter 2000-2001 in Łebsko Lake. Fecundity estimates were calculated from a sample of 43 female ovaries. The age of the studied whitefish ranged from 2+ to 9+. Specimens aged 2+ predominated. In the first year of life the whitefish reached a body length (longitudo corporis – l.c.) of 12.2 (± 2.9) cm and a weight of 255 (± 150.1) g. In subsequent years these figures were as follows: second year – 30.8 (± 5.9) cm and 775 (± 287.9) g; fifth year – 27.3 (± 4.7) cm and 2581 (± 315.8) g; ninth year – 53.9 cm and 3878 (± 124.2) g. Average fecundity ranged from 46.8 (± 6.3) to 154.4 (± 13.4) thousands eggs in segregated size classes.
Key words: WHITEFISH (COREGONUS LAVARETUS), AGE, GROWTH, FECUNDITY, ŁEBSKO LAKE
CORRESPONDING AUTHOR:
Prof. dr hab. Andrzej Martyniak, Uniwersytet Warmińsko-Mazurski, Katedra Biologii i Hodowli Ryb, ul. Oczapowskiego 5, 10-957 Olsztyn, tel./fax: +48 89 5233290; e-mail:kbhr@uwm.edu.pl