The hemisessile lifestyle and feeding strategies of Iosactis vagabunda (Actiniaria, Iosactiidae) a dominant megafaunal species of the Porcupine Abyssal Plain
Iosactis vagabunda Riemann Zurneck, 1997 (Actiniaria, Iosactiidae) is a small endomyarian anemone, recently quantified as the greatest contributor to megafaunal density (48% 2372 individuals ha?1) on the Porcupine Abyssal Plain (PAP) We used time lapse photography to observe 18 individuals over a period of approximately 20 months at 8 h intervals, and one individual over 2 weeks at 20 mine intervals, and report observations on its burrowing activity, and both deposit and predatory feeding behaviours. We recorded the apparent subsurface movement of an individual from an abandoned burrow to a new location, and burrow creation there. Raptorial deposit feeding on settled phytodetritus particles was observed, as was predation on a polychaete 6 times the estimated biomass of the anemone. Though essentially unnoticed in prior studies of the PAP, I. vagabunda may be a key component of the benthic community, and may make a critical contribution to the carbon cycling at the PAP long term time series study site.