Sensory and Chemical Ecology Group

PHEROMONAL MEDIATION OF MATURATION AND SPAWNING IN NEREID POLYCHAETES

Staff: Joerg D Hardege (PI) Helga Bartels-Hardege (PDRA), Matthew Davies (Technical support)

The aim of this project was to understand the final biochemcial events leading to fully fertiliziable, competent gametes in marine invertebrates and specifically to investigate the potential role of chemical signal molecules. This pilot study was designed to lead into future investigations into applicability for aquaculture as well as possible intereferences with environmental disrupters. :

Objectives:

Specific questions to be answered were:
• Is the sex pheromone production a fundamental requirement for a) onset of fertiliziability of gametes, b) the release of gametes into the environment and c) a high survival rate of larvae ?
• Do Nereid polychaetes use gamete activating and attracting pheromones to guide sperm to eggs ?
• Is there a direct correlation between pheromone content and viability of offspring ?

Results and outcome

Currently available data indicate that in Nereis succinea and Platynereis dumerilii female sex pheromone production is late during oocyte maturation with a clear correlation between oocyte diameter and pheromone content, and that exposure to pheromones can in some cases induce release of immature gametes. There is a correlation between pheromone production and fertilizatiabilty of gametes but no evidence for the presence of gamete attraction was found.

New projects that resulted from this study:

Investigation into the correlation between pheromone biosynthesis and onset of spawning activity in female Nereis succinea.