| An objective of sexual selection research is to explain the evolution of display ornaments. Recent literature suggests that the symmetry of bilateral ornaments may be useful to females as an honest indicator of male quality. This idea was tested by examining the relationship between bilateral ornament size, ornament symmetry and two measures of individual quality, body condition and parasite load, in four groups (adult and juvenile, male and female) of pumpkinseed sunfish Lepomis gibbosus. Pumpkinseed grow fleshy extensions called opercular doceomores on their gill covers. The doceomores are predominately black in colour with a posterior red pigmented spot. These bilateral ornaments are presented by erecting the gill covers in a dramatic frontal display. The results show that doceomore fluctuating asymmetry (FA) is indeed negatively correlated with individual quality, but only in females. In contrast, both doceomore size and red spot size are positively correlated with quality, but only in males. Therefore, doceomore size and red spot size can provide potential information on male quality, but their FA can not. Contrary to FA theory, individuals appear able to manipulate the FA of their display ornament. |
