Sponge Mass Mortalities in a Warming Mediterranean Sea: Are Cyanobacteria-Harboring Species Worse Off? (original) (raw)
Figure 4
Several ultrastructural aspects of unhealthy specimens of Ircinia fasciculata.
A, B, C) Zone in the vicinity of a pustule (whitish spot): A) cyanobacteria under several degradation stages; B) section of a degenerating choanocyte chamber with multiple phagosomes (ph) and an unknown microorganism (mi); C) closer view of the “rare” microorganism, which divides within cell vacuoles (a) and shows a membrane complex (arrows) and an irregular, dark inner zone; D, E, F). Zone corresponding to a pustule (died whitish spot): D) completely degenerated cells with multiple released vesicles (v); E) Abundant foreign bacteria (fb), similar to the morphotype reported to consume on the skeleton of dead sponges (Vacelet et al. 1994), among completely degenerated sponge cells (sc); F) Close view of this particular bacterium, which is always associated to the collagen bundles (cb).