The polyp attaches itself to a fish, and in one species exhibits hyperparasitism by attaching itself to a copepod, itself the parasite of a fish.
The larvae are hyperparasites (parasites of parasites), mainly developing in larvae of flies (Diptera, Tachinidae), as well as in wasp larvae (Hymenoptera, Ichneumonidae) parasitizing caterpillars moths (Noctuidae).