GWYNEDD scientists have discovered that a little known hormone causes a creature’s puzzling mating rituals.
Bangor University’s School of Biological Sciences worked on a three year project with Bristol University to disover why millions of Red Crabs from Christmas Island in the Indian Ocean travel from the island’s rainforest to nearby Java to breed.
Professor Simon Webster of the university’s School of Biological Sciences found that the little known crustacean hyperglycaemic hormone helped the crabs maintain their energy levels during the week long journey.
“During the non-migratory period, the crabs are relatively inactive and stay in their burrows on the floor of the rain forest, only emerging for a brief period at dawn, to feed,” he said.
“The behaviour change reflects a fundamental change in the metabolic status of the animal.”
Prof Webster and his team went to Christmas Island to take blood samples and study how the crabs behaved during the dry season and their migration period during the wet season, which lasts from Novemeber until December.
“Somewhat surprisingly we found that hyperglycaemic hormone levels were lower in actively migrating crabs than those which were inactive during the dry season,” he said.
However, the team discovered the reason for this when they injected the crabs with glucose and persuaded them to run and walk. injecting them with glucose.
“During the dry season, forced activity resulted in a tremendous release of hormone, within two minutes, irrespective of whether glucose had been injected,” he said.
He said that the crabs injection of glucose completely prevented exercise dependent hormone release, which showed that glucose levels clearly regulated hormone release at this time.
“This makes sense since it ensures that during migration, glucose is only released from glycogen stores when glucose levels are low, thus eking out the crabs’ precious reserves of glycogen, to ensure that they can complete the migration.”