<Ul> <Li> A species of pufferfish and two triggerfish have been observed to feed on crown - of - thorns starfish in the Red Sea, and, although they may have some effect on the A. planci population, no evidence exists of systematic predation . </Li> <Li> The Triton's trumpet, a very large gastropod mollusc, is a known predator of Acanthaster in some parts of the starfish's range . The triton has been described as tearing the starfish to pieces with its file - like radula . </Li> <Li> The small painted shrimp Hymenocera picta, a general predator of starfish, has been found to prey on A. planci at some locations . A polychaete worm, Pherecardia striata, was observed to be feeding on the starfish together with the shrimp on an east Pacific coral reef . About 0.6% of the starfish in the reef population were being attacked by both the shrimp and polychaete worm, killing the starfish in about a week . Glynn suggested this resulted in a balance between mortality and recruitment in this population, leading to a relatively stable population of starfish . </Li> <Li> Since P. striata can only attack a damaged A. planci and cause its death, it may be regarded as an' impatient scavenger' rather than a predator . As distinct from predators, dead and mutilated adults of A. planci attract a number of scavengers . Glynn lists two polychaete worms, a hermit crab, a sea urchin, and seven species of small reef fish . Apparently, they are able to tolerate the distasteful saponins for an easy meal . </Li> <Li> A large polyp - like creature of the cnidarian genus Pseudocorynactis was observed attacking, and then wholly ingesting a crown - of - thorns starfish of similar size . Continued studies revealed this polyp is able to completely ingest a crown - of - thorns specimen of up to 34 cm (13 in) in diameter . </Li> </Ul> <Li> A species of pufferfish and two triggerfish have been observed to feed on crown - of - thorns starfish in the Red Sea, and, although they may have some effect on the A. planci population, no evidence exists of systematic predation . </Li> <Li> The Triton's trumpet, a very large gastropod mollusc, is a known predator of Acanthaster in some parts of the starfish's range . The triton has been described as tearing the starfish to pieces with its file - like radula . </Li> <Li> The small painted shrimp Hymenocera picta, a general predator of starfish, has been found to prey on A. planci at some locations . A polychaete worm, Pherecardia striata, was observed to be feeding on the starfish together with the shrimp on an east Pacific coral reef . About 0.6% of the starfish in the reef population were being attacked by both the shrimp and polychaete worm, killing the starfish in about a week . Glynn suggested this resulted in a balance between mortality and recruitment in this population, leading to a relatively stable population of starfish . </Li>

What is the issue of the crown-of-thorns starfish