Climate shifts web guru and contributor Jez Roff has an eye for peculiar marine critters and phenomena including large worms, pink dolphins , giant crabs, and fashionable turtles.

He is the lead author of a new Reef Site article published in the journal Coral Reefs about corals that extrude mesenterial filament to tidy up new surfaces before then grow onto them.

Peripheral polyp mesenterial filaments at the lesion margins were observed to actively “sweep” and remove detritus within the perimeter surrounding the recovering lesions (Fig. 1b). Our observations of pre-emptive cleaning appeared to be linked with extracoelenteric digestion of detritus by the mesenterial filaments (Fig. 1c), exposing the glass slide to a width of several polyps. The continuous removal of detrital and algal material facilitated tissue expansion by the prevention of competitor settlement and by the preparation of substrates for calcified coral growth (Fig. 1d).

Fig. 1 a Accumulation of detrital matter on glass slides following lesion induction of Acropora pulchra branches. b Pre-emptive cleaning of substrates (perimeter marked by black arrows) surrounding growing margins ofAcropora pulchra by mesenterial filaments (white arrows). c Close-up of protruding mesenterial filaments actively feeding and removing detritus. d Tissue growth and calcification onto cleaned surface 90 days following lesion formation (scale = 3 mm)