39THE SYDENHAM HAS A LOT OF "MUSSEL!"

Reproduction

Mussels have an interesting method of reproduction. Mussels start out as larva that require a host. This means that baby mussels (larva) need another animal (host) on which to live. The host can be a fish or a mudpuppy, an aquatic salamander.

The first step of the cycle involves the fertilization of the female mussel by the male mussel. The male releases his sperm into the water and the female takes them into her gills where her eggs are kept. The fertilized eggs develop into little mussels (larva) called glochidia. Glochidia are released under certain circumstances depending on the species of mussel. Some mussels are sensitive to the light and if a shadow passes over them they jet the mini mussels into the path of what they hope is a fish host.

If it is, the fish swallows all of the baby mussels, thinking they are food. Once the glochidia enter the fish, they move to the fish’s gills and stick to them. This is the parasitic stage of the mussel's life cycle. Parasitic means they take from the fish without the fish benefiting from the relationship. Even though the mussels are taking advantage of the fish they do not harm it. The mussels stay for a week to a month; they drop off once they are ready to live on their own.

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