MP10 PCB Toxicity in Aquatic Organisms- Endocrine Effects
Monday, 14 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(RIP-1117-661042) Developmental exposure to PCBs through the placenta-like paternal brood pouch of two pipefishes.

Ripley, Jennifer¹, Foran, Christy¹, ¹ West Virginia University, Morgantown, WV, USA

ABSTRACT- Pipefishes and seahorses of the family Syngnathidae are characterized by a unique mode of reproduction in which the male carries the embryos from fertilization until the fry are free-swimming in a specialized organ commonly referred to as the brood pouch. In an earlier study we investigated the role of the paternal brood pouch in nutrient transfer. We uncovered differences between two related pipefish species of the Chesapeake Bay in the relative contribution of males and females to developing offspring. Fry become implanted adjacent to blood vessels in the male brood pouch and females produce nutritionally poor eggs in the Northern pipefish, Syngnathus fuscus. On the contrary, females of the Dusky pipefish, Syngnathus floridae, produce nutrient-rich eggs which males appear to utilize as nurse eggs. Because of the potential for lipophilic contaminants to be transferred to developing pipefish through the paternal brood pouch, pipefish are likely to be exposed to contaminants during critical stages of development, analogous to human in utero exposure. We hypothesize that toxicant exposure during brooding will exhibit a greater impact on development of S. fuscus offspring than S. floridae, stemming from the production of sperm-like gametes by S. fuscus females versus nutrient-laden eggs by S. floridae and a related decline in dependence on paternal resources. We mated pipefish, collected from a relatively pristine site in Chincoteague Bay, Virginia, in the laboratory and exposed brooding males to high and low environmental concentrations of the PCB mixture Aroclor 1254 until fry were released. We indeed found S. fuscus development was impacted. Pipefish provide a unique model to investigate developmental impairment from placental exposure; due to the accessibility to brood fry and the large number of young per brood, the impact of embryonic contaminant exposure can be assessed rapidly.

Key words: PCB, development, placenta, Chesapeake Bay