Copepods leave chemical traces in the water in which they live. Some of these chemicals may be signals of conspecifics. Can we find the signal molecules among the thousands of substances that occur in seawater? This paper develops new methods in the search for copepod sex pheromones and identifies candidate molecules.
The females of most species of pelagic copepods produce sex pheromones to attract males, but the sex pheromones molecules have never been identified. We developed a simple method to extract, capture and test metabolites from small planktonic organisms. We find sexual differences in exudate composition, reflecting the sexual dimorphism, with female specific exudates being possible sex-pheromones. We are able to remove the female sex pheromone from seawater using solid phase extraction columns, but were unable to re-gain the molecules and their activity as revealed in behavioural assays. One possible explanation is that sex pheromones are a cocktail of several molecules that need to be in the correct proportions to elicit male searching behaviour.
Read the paper online here.
Heuschele J, Nemming L, Tolstrup L, Kiørboe T, Nylund GM, Selander E (2016) The sex specific metabolomics footprint of Oithona davisae, J Sea Res 117: 1-6.