How long is the longest food chain in this food web? (i. e., the one with the most "links") ?

Black-crowned night-heron. This predator is adapted to hunt at night. In the French Guiana this is one of the major night heron species with its cousin the Yellow-crowned night-heron (Nycticorax violacea). Feeds mainly on aquatic animals, including fish, amphibians and insects. Coastal swamps.