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.
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.
Variation of scales on the blind side of Pseudopleuronectes yokohamae in relation to sex, maturity and body size was examined. Immature males often have cycloid scales, while mature males have mostly ctenoid scales. Large females also often have ctenoid scales (but with fewer spines compared with males), and small females have mostly cycloid scales. The number of spines (ctenii) on the blind-side scale increases with body size in both sexes, indicating an ontogenetic change in scale morphology. As P. yokohamae spawn demersal eggs with males positioning themselves above the females on the ocular side, it is hypothesized that ctenoid scales on the blind side in mature males function for maintaining contact with females during spawning.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.