The Many Faces of Trichodesmium

What's in a name? Trichodesmium pelagicum used to have its own genus: Katagnymene. Once scientists started looking at their DNA, they realized that Katagnymene and Trichodesmium were the same thing. They have curly trichomes (or filaments,) and the little black bars are their "friends," bacteria living in culture with them.
(Photo by Annette Hynes, Woods Hole Oceanographic Institution)