Predation on fish larvae by Physalia physalis, the Portuguese man of war

Larval fish comprised 70 to 90% of the prey types found in stomach contents of the neuston siphonophore Physalja physalis (Suborder Cystonectae).Specimens at one station were estimated to consume an average of 120 fish larvae daily, about 60 % of the larvae that were available at 0 to 5 m depth.Only soft-bodied prey were captured (fish and fish larvae, cephalopods, chaetognaths, leptocephalus larvae); this may be related to the structure of nematocysts found in cystonect siphonophores.