Meeting Abstract
83.5 Monday, Jan. 6 11:30 Chemical characterization of a species identifying pheromone in the common carp (Cyprinus carpio) GHOSAL, RATNA*; LEVESQUE M, HAUDE; SORENSEN W, PETER; Department of Fisheries, Wildlife and Conservation Biology University of Minnesota St. Paul, MN 55108, USA rghosal@umn.edu
Pheromones, chemical information that passes between members of the same species, are commonly used by fishes. This presumably is a consequence of the ease with which chemical cues pass through water and the lack of light which characterizes aquatic ecosystems. Generally, fish pheromones are species-specific but how this might be is a paradox because all pheromonal compounds identified to date are relatively common metabolites of hormones or biliary sterols: no specialized species-specific products have been identified. To address this, we recently hypothesized that species-specificity in fish pheromones may be conveyed by species-specific combinations of suites of metabolites or ‘complexes’ rather than novel products. To test this, we examined the chemical complexity of the odor released by juvenile common carp, which we previously found to drive aggregation. Holding waters of juveniles were fractioned into nonpolar and polar fractions using C18 columns and their behavioral activity tested in attraction mazes. We found partial activity in both the polar and the nonpolar fractions. Further evaluation of the nonpolar fraction found it to contain at least two active components. Finally, we tested the long-standing hypothesis that mixtures of L-amine acids, a major class of fish odorant, might have pheromonal activity. Analysis of carp holding water found it to contain all 20 primary amino acids with asparagine and cysteine being dominant and at different ratios than for food. However, when these mixtures were tested we found that while the food amino acid mixture was attractive, the carp mixture was not. We now speculate that species-specific peptides, perhaps related to MHC, may play a role in fish pheromone complexes. (Funded by the Minnesota Environmental and Natural Resources Trust Fund)
