PIs: Joerg D. Hardege, Thomas Breithaupt

The aim of this project is to use recently developed behavioural and physiological assays and the availability of large numbers of ‘peeler crabs’, (pre-moult females) to identify the female produced sex pheromone in Carcinus maenas.

Aquatic chemical ecology is an area of research that has been growing rapidly within the past two decades. Chemical cues are involved in mediating a wide array of ecological inter-and intra-specific interactions among organisms and play a key role in determining community structure and ecosystem function. This includes prey perception, habitat selection, predator avoidance and aspects of crustacean reproduction such as mate choice, social hierarchies and the reproductive behaviour. Despite their ubiquity and importance, few signal molecules have been characterised in marine organisms. In malacostracan crabs the female emits attractant pheromones that induce courtship display and reproductive behaviour in the male. Perhaps the best studied crustacean sex pheromone is that of the shore crab, Carcinus maenas. Nevertheless, little progress has been made in identifying the chemical nature of the crab sex pheromones as a consequence of difficulties associated with the bioassays employed, and the water soluble chemical nature of the cues. Moulting provides a window of opportunity to mate before a physical barrier develops to male first pleopod insertion.

OBJECTIVES

We are addressing the following questions for this project:

1. What is the chemical nature of the female sex pheromone?

2. Is the sex pheromone a biosynthetic by-product of ‘moulting’ (chitin synthesis linked?) that is released ‘non-intentional’ and as such also occurs when males moult during the spring?