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Gonad parasitisation

Male Asterias rubens are hosts for the protozoan Orchitophrya stellarumo. The protist causes atrophy of the male testes which leads to castration. Orchitophrya stellarumo infect their host right before or during the mating season, which is during January and May. This is when the males testes are developing or are fully developed. Since the protist deteriorates the reproductive organs of the males, these parasites have a directly negative effect on Asterias rubens's population growth.

Human Interactions
Asterias rubens are not very beneficial to humans. They are in fact considered a pest by fisherman because they compete for their catch of oysters and mussels. Due to their regenerative abilities, the sea stars are not easy to exterminate and are usually found in large groups. This allows them to eat whole colonies of mollusks in a very short time.

Sea stars can be beneficial to humans in one way. Sea stars are very sensitive to alterations in their environment and can be used to indicate ecological changes. Sea stars are susceptible to heavy metals, oil, excessive silt, change in pH, and extreme changes in salinity levels.

A very large group of Asterias rubens

Photo courtesy of Dirk Schories at http://www.guiamarina.com/

Send questions or comments to richards.mic2@students.uwlax.edu