Diet of a notodelphyid copepod inhabiting in an algal-bearing didemnid ascidian Diplosoma virens

A notodelphyid species inhabits in the colonial ascidian, Diplosoma virens that contains photosynthetic symbionts Prochloron sp. in the cloacal canal. The gut contents of the notodelphyids were examined by light and electron microscopy to estimate their diet. Since the gut contents are almost homoge neous, the notadelphyids are probably monophagous. The histochemical staina bility of the gut contents suggests that they mainly feed on the host tunic . Although the host faeces and the fragments of the algal symbionts are som etimes found in the gut contents, they would be accidentally ingested by th e notodelphyids.