The incredible mind-control and journey of a parasite

From Pennyslvania Boat and Fish Commision, is this description of the life cycle of a fish parasite. The "Black Spot" parasite has be born in the belly of a bird, get passed to the water, live in a snail, before it progresses to live in a fish. Link.

Incredibly,iIn order to increase the chances of a bird eating a host fish, the parasite actually alter fish behavior, causing it to swim awkwardly and nearer the surface, where a bird will more likely grab it.

The lifecycle of the "black spot" parasite is complex. The adult parasite is found in a fish eating bird, the kingfisher. The larval parasite is transferred from the infected fish to the bird during the feeding process. In the kingfisher, the larval stage develops into an adult parasite. The adult parasite in the intestine of the bird produces eggs that are eventually deposited in the water. There the eggs mature, hatch, and develop into the miracidium stage of the parasite. The miracidium infects a snail. In the snail, the miracidium develops into the cercaria life stage. The cercaria leaves the snail and actively penetrates a host fish. In the fish, the parasite becomes encysted. In about 22 days, black spots form around the cyst. This entire lifecycle takes at least 112 days to complete.

!SR