Used in: Animals Two by Two, Structures of Life, Environments, Population and Ecosystems, Diversity of Life

Elodea (also known as Anacharis or Egeria) — Egeria (Elodea) densa (native to Brazil) or Egeria canadensis (native to North America)

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Background. Plants occupy the base of the food pyramid in aquatic systems just as they do in terrestrial systems. The popular aquatic vascular plant that looks like a green feather boa is elodea. In nature it is usually rooted to the bottom of a stream or pond, but in your aquarium it can just float around. It is a good food source for amphipods, fish, and crayfish and will contribute to the oxygen in the water as it photosynthesizes. It also provides crannies where small animals can hide from predators.

Obtaining elodea. You can order elodea from Delta Education or you can pick it up locally at a pet store that deals with fish. There are several different species of elodea, and some of them are restricted in some states. Ask your supplier for the species that can be safely distributed in your state. Note that as of this writing in 2016, Egeria densa is prohibited in AL, CA, CT, ID, IL, IN, LA, MA, ME, MI, MN, MS, NE, NH, NY, OR, PR, SC, VT, WA, and WI. Egeria najas is prohibited in CA. Elodea canadensis is prohibited in LA and ME. (Source: Water Lily Database.)

What to do when the plants arrive. Open bag and rinse plants in dechlorinated or spring water. Keep elodea floating in bowl of dechlorinated or spring water to avoid drying out until it's ready to use.

What to do with them when the investigations are completed. Elodea can be placed in a permanent aquarium or offered to another teacher about to conduct the investigations. Aquatic plants and animals obtained from pet stores or biological supply houses should never be released into the local environment. There is always a chance that an introduced species might displace a native species in the environment, so releasing such organisms is never an option. Several species (see above) are now considered invasive pests in North America and should not be released in any local water sources. As a last resort, you can put the plants in a bag, place them in a freezer overnight, and dispose of them in the trash.