SEX-RELATED GROWTH OF EUROPEAN EEL, ANGUILLA-ANGUILLA, WITH FOCUS ON MEDIAN SILVER EEL AGE

Silver eels, Anguilla anguilla, migrating downstream were monitored fo r 15 years since being stocked in 1980 as cultured fingerlings in a Sw edish lake. Females were larger than males in each separate year, but mean growth rate was higher in males than in females. This discrepancy was due to different age distributions, with 64.5% of the males migra ting after four or five growing seasons, while 86.3% of the females gr ew for 10-15 seasons before migration. Otolith length in the glass eel stage was independent of sex, and it was not correlated with year of migration. With focus on median year of migration, otolith lengths aft er one, two, and three growing seasons were significantly larger in ma les than in females. This was mainly due to a higher otolith length in crease during the first growing season, i.e., before the eels were sto cked in the lake. These results are inconsistent with the view that fe male eels generally grow faster than males.