Did pollination originate on earth with bees or millions of years earlier, at the bottom of the ocean? The discovery of the role of the idotea, a marine crustacean, in the fertilisation of red algae, is turning our knowledge of animal-plant interactions upside down.

According to a recent study in the Science journal, scientists have found that a tiny crustacean, Idotea balthica, played the role of pollinator for a species of seaweed. They inadvertently collect the algae’s sticky spermatia – its equivalent of pollen – on their bodies and sprinkle it around as they move in search of food and shelter.

This is the first time an animal has been observed fertilising an algae. This discovery not only extends the scope of species that use this reproductive strategy, it also raises questions about whether it first evolved on land or in the sea.

It was long thought that animals only pollinated plants on land, but in 2016, scientists found that zooplankton pollinate Thalassia testudinum, a sea grass species found in the Caribbean. Sea grasses are the only flowering plants that grow in marine environments, but they remain closely related to terrestrial plants. Seaweeds on the other hand, while technically plants themselves, are not closely related to terrestrial plants.

Published in Dawn, October 8th, 2022