Abstract
The objective of this study was to determine the influence of tissue morphometry on tissue total mercury concentration (THg) in male and female virile crayfish (Faxonius virilis). In 2023, ten embryonized, and nine stage IV females, as well as 29 male virile crayfish were captured from Lake Roosevelt and the Spokane River Arm, in Washington, USA. THg was analyzed in the adductor muscle, gills, and hepatopancreas for all individuals, and the ovaries and eggs for females with developed ovaries and embryonized females, respectively. Tissue morphometrics and tissue THg were allometrically correlated to the clawless body mass (CBM) of male virile crayfish. Furthermore, it was determined that in male size-adjusted virile crayfish, gill THg was significantly associated with hepatopancreas THg, but not adductor muscle THg. In embryonized and reproductive developing female virile crayfish, there was evidence of considerable adductor muscle and hepatopancreas tissue atrophy, however, no significant differences in THg occurred. In both the adductor muscle and the hepatopancreas, THg was not bioamplified despite tissue atrophy, suggesting a net loss of mercury from the tissues into the hemolymph. While the most plausible redistribution of mercury in females with developed ovaries would be from the hepatopancreas to the developing ovary, this redistribution does not completely explain the level of maternal transfer observed. Clearly, dietary mercury contributed to the body burden of mercury within the ovaries of the females in reproductive development.