Use of Pheromones in the Management of Asian Carp Edward E. Little and Robin D. Calfee U.S. Geological Survey Columbia Environmental Research Center Columbia, MO 65201 U.S. Department of the Interior U.S. Geological Survey
Pheromones • Pheromones are chemical signals that pass between organisms and mediate behavioral and physiological responses. • Pheromones are perceived through olfactory system and are generally species-specific. • Common carp appear to have a chemically mediated social network where pheromones mediate: • Alarm responses • Social aggregation – schooling • Reproduction
Asian Carp Pheromones Alarm Pheromones Induce avoidance and antipredator responses, possibly useful in diverting fish. Aggregation Pheromones Released by schooling carp, attracts individuals to the school, possibly an attractive lure. Sex Pheromones? Necessary for common carp and goldfish reproduction.
Sex Pheromones • Goldfish pheromones synchronize gonadal development and induce a sequence of behavioral responses leading to spawning. • Aggregating pheromones may be released from surface mucus. • Sex pheromones are released from the gills and in urine.
Sex pheromones of fish are likely a mixture of hormonalprecursors and metabolites that vary with sexual status.
Electro-olfactogram (EOG)A great screening tool Olfactory responses to specific odorants DC amplifier Rosette of a nose
EOG response of bighead carp 1 mV 4 sec 10-8 M 10-12 10-11 10-10 10-9 10-5 M Serine Blank control (Food) 15keto-Prostaglandin F2α (Putative sex pheromone) From Lim and Sorensen, unpublished
Gluc—O ßOH OH OH O O 3 of 47 steroids were potent O O 17,20βP 17,20βP-glucuronide O S O O OH 17,20βP -sulfate From Lim and Sorensen, unpublished
Conclusions • Bighead and silver carp show extreme olfactory sensitivity to specific metabolites of sex hormonal. • In mixtures these may form the sex pheromone. • Likely a similar, but not identical pheromone as found in other cyprinid fishes. • Pheromones modulate behavior, thus the response may be variable.
Next Steps • Behavioral tests with metabolites Juvenile fish Hormonally induced fish • Development of field protocols for quantifying response to pheromones • Proof of concept study with hormonally induced female carp?