Scientists on brink of developing fish contraceptive


Scientists in the US may have developed a contraceptive which can be used on invasive fish.

A team of researchers from the University of California studying the evolution of oestrogen receptors and signalling discovered the active part of the oestrogen receptor in the Sea lamprey Petromyzon marinus.

This jawless fish is an extremely invasive pest in the Great Lakes area of the United States where they eat large quantities of trout, salmon, sturgeon and other game fish.

The study created a 3D model of the lamprey oestrogen receptor and found that lamprey oestrogens are almost certainly unique to these fish in their interactions.

This means that certain compounds may well interfere with the lamprey s oestrogen action whilst not affecting any other fish in the area. This could play an important part in control of lamprey numbers as it can be used in the screening of chemical controls for lampreys.

Lampreys evolved about 450 million years ago and contrast to sharks, fish and land vertebrates, lampreys have no jaw.

They feed on fish by attaching themselves to the fish and sucking their body fluids.

Their aggressive consumption of game fish has eliminated many natural predators of another invasive species on the Great Lakes known as the alewife.

This has allowed the alewife population to explode, with a knock on affect on many other native fish species.

Michael E Baker the key scientist and professor in the University of California s San Diego Department of Medicine said: Since the introduction of sea lamprey to the Great Lakes, the fisheries have been devastated, and as a result, there is much interest in finding new methods to control the lamprey population.

Our research could lead to a contraceptive for female lamprey, providing a method to control their reproduction in the Great Lakes.

For more information see: Baker ME, Chang DJ, Chandsawangbhuwana C (2009) 3D Model of Lamprey Estrogen Receptor with Estradiol and 15-Hydroxy-Estradiol. PLoS ONE 4(6): e6038. doi:10.1371/journal.pone.0006038