Morphometric variation of yellowtail flounder

Significant variation in morphometry was found between sexes of yellowtail flounder and among eight geographic areas, from the Grand Bank to the Mid-Atlantic Bight. Females had relatively deeper abdomens and larger heads than males. Newfoundland samples had relatively shorter bodies, deeper abdomens and longer heads than those from south of Nova Scotia. Morphometric analyses classified 71–95% of yellowtail to the correct Canadian area, but accuracy was lower for areas off the northeastern United States (43–76%). Morphometric differences are consistent with differences in ontogenetic rates among groups. However, shape differences were not strong enough to delineate geographic stocks off the northeastern United States.