Effect of wound size on the growth and regeneration of two temperate subtidal sponges

Physical and biological disturbances can damage and remove biomass from marine invertebrates such as sponges. To determine the effect of wound size on sponge recovery, individuals of the Demospongiae Latrunculia wellingtonensis (Alvarez, Berqguist and Battershill) and Polymastia croceus (Kelly-Borges and Bergquist) had 50%, 75%, 90% or none (control) of their volume removed. Regeneration (measured by oscule development), growth (percent and volume change), biofouling and survival were monitored often over 203 days using in situ photographs. The rate of regeneration and growth varied between the two sponges, being greatest for L. wellingtonensis. Interspecific variation may result from differences in choanosome structure: the choanosome in L. wellingtonensis is poorly differentiated but is well developed in P. croceus. For each species, recovery rates were similar between 50%, 75% and 90% removed sponges. All damaged L. wellingtonensis and P. croceus survived, demonstrating the remarkable ability of some sponge species to recovery from massive injuries. L. wellingtonensis and P. croceus are often found in exposed habitats. Good recovery after injury may therefore be an adaptation to reduce the damaging effects of storms and strong water movement.