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Pouch Snails

Benthic Macroinvertebrates

Sensitive Benthos

Moderately Tolerant Benthos

Pollution Tolerant Benthos

Description:

Physella  sp. - photo by Wayne Davis USEPA

Physella sp.

distinguished from  the "right-handed" snails by the fact that the shell opening is on the left-handed side as the point of the shell [spire] is straight up and the opening faces  you; does not possess gills, but a sac-like lung with which they can breath air; color is brown, gray or black, often with algae growing on the shell; length is up to 1/2 inch.

Reproduction:

gelatinous egg masses are deposited under rocks or other debris.

Food:

algae, other aquatic plants, and  sometimes dead animals; preyed upon by fish, birds, and some turtles.

Scientific Name:

  Class: Mollusca
    Order: Gastropoda
      Family: Physidae

Indicator Role:

Pouch snails generally indicate nutrient enriched conditions and poor water quality.

Information Source:

McDonald, B., W. Borden, J. Lathrop.1990. Citizen Stream Monitoring: A Manual for Illinois. Illinois Department of Energy and Natural Resources, ILENR/RE-WR-90/18. Springfield, Illinois.

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Biological Indicators | Aquatic Biodiversity | Statistical Primer


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