Story: Marine animals without backbones

Flatworm life cycle

Flatworm life cycle

Parasitic flatworms are also known as flukes. One New Zealand species, Curtuteria australis, is a common parasite of shellfish and shorebirds. They start life as eggs that are passed out in the faeces of birds such as oystercatchers. If eaten by a mudflat snail, or whelk, the eggs hatch and the larvae multiply by budding. The tiny fluke larvae leave their whelk hosts and invade another shellfish, cockles. The larvae accumulate in the foot of cockles, preventing them burrowing into the mud to escape predation. The stranded cockles are eaten by oystercatchers. Once inside the bird, the flukes mature and produce fertilised eggs, and the cycle begins again.

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Source: Robert Poulin, Going in circles: the complex transmission routes of parasites. Dunedin: University of Otago Press, 2004

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How to cite this page:

Dennis Gordon and Maggy Wassilieff, 'Marine animals without backbones - Simple worms', Te Ara - the Encyclopedia of New Zealand, (accessed 12 August 2022)

Story by Dennis Gordon and Maggy Wassilieff, published 12 Jun 2006