Bees of the seas
New research has uncovered ‘pollinators’ – marine crustaceans – fertilising seaweed in our oceans
The world’s oceans contain about as few insects as they do flowering plants, and yet new research shows that ‘pollinators’ do occur in the sea. It’s just that they are not insects and it’s not flowers they’re pollinating. Biologists have discovered that slender wart weed, a red seaweed that grows in shallow UK waters, is ‘pollinated’ by a woodlouse-like marine crustacean named Idotea, which transports the spermatia – the algal equivalent of pollen – from male to female plants. “When we found these crustaceans were highly associated with the algae, particularly
Myriam Valero, a scientist at CNRS, the French national research agency during the reproductive season, that’s when we thought that maybe they are helping with fertilisation,” says Myriam Valero, who led the research from France’s University ParisSorbonne. In return for their services, the crustaceans find food and shelter among the seaweed’s fronds.
While the sex cells of many seaweeds are able to swim using tail-like flagellae, those of red algae lack any form of propulsion. Without the crustaceans’ help, the seaweed’s sex cells would be at the mercy of currents.
“Although red algae are very different to flowering plants, in a way these systems are very similar,” says Valero. “We are now looking at another red alga species in Chile, where there are no Idotea present, but there is another crustacean species that might be performing a similar role.”
Red algae are an ancient group of plants, raising the possibility that they enlisted the services of invertebrate ‘pollinators’ long before flowers appeared.