Question

When giant sea anemones which housed the anemone-toxin-resistant clownfish (also known as anemonefish) were deprived of their partners what was the result?

Answer 1

The anemones were attacked by butterflyfish and retreated into reef holes
An experiment published in 2004 observed: "When anemonefish were experimentally removed, sea anemone hosts contracted partially. Within 1–4 h in most cases, individuals of the butterflyfish Chaetodon fasciatus arrived and attacked the sea anemones, causing them to contract completely..." with reversal of the process when even one large clownfish was returned. The experiment concluded "Host sea anemones that lack anemonefish large enough to defend them against predation may remain contracted in reef holes, unable to feed or expose their tentacles for photosynthesis, resulting in their shrinkage and eventual death".