Fish Intersexuality as Indicator of Environmental Stress

By: Stephen A Bortone and William P. Davis.

Faith Warren Presentation Date: 04/29/2014Dr. Pease

Picture 1 Picture 2

Picture 3

Eleven Mile Creek

Fenholloway River ^^

Figure 1: “Normal female (top) and male mosquitofish (bottom). A masculinized female is pictured in the center, showing the gonopodial elongation of the anal fin.”

Figure 2: “An array of anal fins from the least killifish. A.) Normal female. B.) Fish exposed to kraft-mill effluent; note the increased segmentation at the tips of the rays. C.) Another example of a fish exposed to kraft-mill effluent with some elongation of the fin rays. D.) Normal male.”

Hermaphroditism: “describes a subcategory of intersexuality where the primary reproductive characters (testes and ovaries) are found in a single individual.” “The study shows that reproductive systems in fishes are useful bioindicators for detection of substances that interfere with endocrine modulated processes… Poeciliid fishes such as the mosquito fish and the least killifish can be useful to detect endocrine disruptors.”

What does this mean for managers of aquatic resources?

“Developing a well-documented and well-referenced system to recognize the subtle changes in intersexuality in fishes represents a step in the right direction to better monitor the health of aquatic ecosystems.”

For more information here is the full paper:

http://eds.b.ebscohost.com.lib-e2.lib.ttu.edu/eds/pdfviewer/pdfviewer?sid=d0ccf185-bab2-42f7-af4e-06c1b1baee53%40sessionmgr112&vid=4&hid=119