Hobbies And Interests
Mussels
Mussels are aquatic bivalve mollusks. This means that they live in marine/saltwater or freshwater habitats, and have soft bodies encased within a structure made of two shells (or valves) connected by a hinge ligament. Despite their numerous species, there are primarily two kinds of freshwater mussels: burrowing mussels that can produce pearls, and those called "fingernail clams" or "freshwater clams," grouped in the family Unionidae. However, freshwater mussels are highly diverse in color, size and life span. Depending on the species, adults can live 10 to more than 100 years.
Mating and Fertilization
Almost all freshwater mussels reproduce sexually. However, unlike other animals that actively look for mates, mussels use water currents as their vehicle of reproduction. The mating cycle starts when the male, located upstream, releases sperm into the water. As the female, who is positioned downstream, filters the water for food, she draws in the sperm through her siphon. Once her eggs are fertilized, they develop into microscopic larva called glochidia.
Developmental Stages
Once the glochidia are mature, the female mussel releases them into the water to begin their second phase of development. At this stage, the glochidia attach themselves onto the bodies of fish and live as parasites. Fish can carry up to 3,000 glochidium within various sites -- including gills, fins and other internal structures -- unknowingly and without harmful repercussions. Many varieties of mussel glochidia can only survive if they attach themselves to a specific species of fish.
Over the course of several weeks, the glochidia form feet, gills and other parts. Once glochidia are transformed into juvenile mussels, they are still microscopic, but will extract themselves off of the fish, and migrate to the bottom of their stream or other water hole. Over time, a shell is formed by cellular secretions in the mussel's body wall called a mantle. Adult mussels usually don't move any greater that a few feet in distance throughout their life span.
Industry, Conservation Status and Cultivation
In addition to being a popular food source, mussels are also used in the jewelry industry for their ability to produce pearls and mother-of-pearls. In spite of their commercial usage, mussels have become endangered primarily because of non-industry related factors such as water pollution, infestations of exotic species and dams. For this reason, efforts are being made by various private and government entities to develop better techniques to cultivate freshwater mussels in laboratories and reintroduce them to natural environments.