Aggregated clumps of lithistid sponges: a singular, reef-like bathyal habitat with relevant paleontological connections.
The advent of deep-sea exploration using video cameras has uncovered extensive sponge aggregations in virtually all oceans.Yet, a distinct type is herein reported from the Mediterranean: a monospecific reef-like formation built by the lithistid demosponge Leiodermatium pfeifferae.Erect, plate-like individuals (up to 80 cm) form bulky clumps, making