SUMMARY OF BRD ENDOCRINE DISRUPTION RESEARCH

Center or Coop Unit: Leetown Science Center

Contacts: Vicki Blazer, Christine Densmore, Thomas Waldrop

National Fish Health Research Laboratory
1700 Leetown Road, Kearneysville, WV 25430

Title of Project: Annual reproductive cycle of largemouth bass and common carp in the Mid-Northeastern Area.

Background: Largemouth bass and common carp are commonly used as indicator organisms for endocrine disruption research - in the BEST monitoring, NAWQA and other programs. However, there is still much we need to understand. Following the reproductive cycle histologically in fish from different geographic areas is something that needs to be documented. Other concerns also need to be investigated. Routinely certain sections of the gonads are taken. Does it matter which areas in terms of stage, histologic biomarkers, or mixed sex determination? Does month collected make a significant in any difference in any of the histologic biomarkers? How do these histologic biomarkers correlate with plasma hormone and vitellogenin measurements each month?

Objectives: Answer the above questions.

Approach: Five to 10 fish of each sex of each species will be collected from a reservoir at the Leetown Science Center. Gonads will be removed and weighed for gonadosomatic index. The whole gonad will be fixed for histology. Eight sections along each gonad will be embedded in paraffin and routinely processed. Each section will be used for histologic staging, presence of mixed sexes, amount of ceroid, percentage of atretic eggs and any other histopathological changes. Blood is taken and cooled, serum collected and frozen at -80 C for later hormone and vitellogenin measurements.

Geographic Location: Northeast; West Virginia

Status: Collections began in May of 1997. They will continue for at least 1 year.