FIG. 1.

Experimental design. Fish were obtained from an AB first-cousin cross and raised to adulthood as were fish from a Tu, AB out-cross, a Tab 14 F9 in-cross, and a TL, AB out-cross. Adults were segregated by sex at 5 months, and 48 male and 48 female siblings from each inbred-AB and hybrid-TuAB line (A), and 32 male and 32 female siblings from each inbred-Tab 14 and hybrid-TLAB line (B) were randomly assigned to eight same-sex, line-specific tanks at a density of six individuals for AB and TuAB (C) or four individuals for Tab 14 and TLAB (D) per tank. Pair crosses were performed with individuals from the same paired tanks, designated for in-crosses or out-crosses before the study, and fish were returned to the same tank after each setup. M, male; F, female.