Center or Coop Unit: Leetown Science Center

Contact(s): Vicki Blazer and Christine Densmore

National Fish Health Laboratory

1700 Leetown Road

Kearneysville, WV 25430

Titles of Projects:

Evaluation of Selected Histologic and Immunologic Biomarkers in Fish Collected for the BEST Pilot Program in the Mississippi Drainage.

Immune, Reproductive and Histologic Evaluation in Fish Collected for the Columbia and Rio Grande Basins BEST Program.

Background: Both of these projects involve fish collected for the BEST monitoring program. The background of this program is described elsewhere.

Objectives: The objectives of the endocrine disruption-related aspects of our particular part of this program involve 1) development of standardized methods for staging male and female gonads of common carp and largemouth bass as well as other species collected; 2) evaluation of gonadal biomarkers such as ceroid deposition, preovulatory and postovulatory eggs and mixed sexes; 3) a comparison of stages with plasma vitellogenin and hormones (done by other investigators) and 4) correlation of our findings with contaminant data.

Approach: Standard histologic methods are used to produce histologic slides. The percent of atretic eggs will be based on counting the number in 100 eggs. Mixed sexes will be noted and the appearance described. Amount of tissue occupied by ceroid will be quantitated using image analysis. We will compare the commonly used staging - i.e. the stage which is most prevalent, or the most advanced stage - to a quantification of the various stages using image analysis. We can then determine if there is significantly more information that can be gained from this quantitative data.

Geographic Location: Mississippi, Columbia and Rio Grande Drainages.