Marine Tubeworm Metamorphosis Induced by Arrays of Bacterial Phage Tail–Like Structures

Abstract

Big MACs Tubeworms are important marine benthic species that encrust rocks and contribute to fouling of man-made objects, such as ships' hulls and drilling well heads. Like most marine invertebrates, the larval stages of tubeworms are free-swimming, but the cues for larval settlement and the triggers for metamorphosis are mysterious. Shikuma et al. (p. 529 , published online 9 January) experimented on larval settlement by the tubeworm, Hydroides elegans , which needs to associate with a biofilm-forming bacterium, Pseudoalteromonas luteoviolacea , before settlement can occur. The bacterium was found to express metamorphosis-associated contractile structures (MACs) in large and structurally elaborate arrays that allow the tubeworm larvae to develop.