Interference with metamorphosis induction in the marine cnidaria Hydractinia echinata (hydrozoa): A structure-activity relationship analysis of lower alcohols, aliphatic and aromatic hydrocarbons, thiophenes, tributyl tin and crude oil

Hydractinia is a marine colonial hydroid. We used the transformation of the freely swimming larvae into the polyp, the founder of the colony, as a test system. That transformation, termed metamorphosis, can be induced deliberately and can be antagonised by various substances at concentrations which neither harm the adult nor the larva but nevertheless this treatment interrupts the life cycle. Here we report the inhibitory influence of various simple organic compounds on metamorphosis induction. In general, the inhibitory influence increased with increasing octanol/water partition coefficient. Within a compound class this rule fits well, but there are differences between such classes.