Chorioallantoic membrane as a non-lethal sampling method for polychlorinated biphenyls analysis in the northern diamondback terrapin (Malaclemys terrapin terrapin)

Polychlorinated biphenyls (PCBs) are documented endocrine-disrupting chemicals. This study examined the bioaccumulation of PCBs and the utility of the chorioallantoic membrane (CAM) as a non-lethal sampling technique for PCB analysis in the northern diamondback terrapin (Malaclemys terrapin terrapin), a species endemic to US East Coast salt marshes. To determine the viability of the CAM as a surrogate for PCB burdens within this species, maternal transfer of PCBs to CAM and egg samples was studied. Egg and CAM samples were collected from populations in Cape May County, NJ and Jamaica Bay, NY; liver samples were collected only from NJ terrapins. PCB congeners were detected in all sample types, but less-chlorinated congeners preferentially partitioned in the CAM. Liver and egg sample PCB concentrations were strongly correlated (p=0.002, r _s=0.883), but PCB concentrations of CAM were not strongly correlated to liver (p=0.035, r _s=0.733) and egg samples (p=0.036, r _s=0.484). Examination of homologue groups indicated a strong correlation between penta- and hexachlorinated biphenyls for all sample types. This study shows that maternal transfer of PCB contaminants occurs with selective partitioning of congeners into the CAM, and that analysis of the CAM alone may not reflect total PCB body burdens in this species.