Scales

Habitats

Fast-moving waters with rocky substrate such as, riffles and runs of streams and rivers; Slow-moving or still waters with soft substrate and vegetation, such as pools and backwater areas of streams and rivers; wetlands and ponds.

Size Range

Aquatic invertebrates have typical size ranges, which can vary according to the conditions (chemcal and physical stability of the aquatic environment) and the availability of food. The ranges in (mm) are shown below:

Size Scale

Stress Tolerance

Stress tolerance is the organism's ability to withstand a certain amount of anthropogenic influences. The index range for each category is based upon a (0-10) scale, which is based mostly on the ability to withstand varying levels of dissolved oxygen and other chemical and physical disturbances. In some cases tolerance values are undetermined (U).

Benthic Scale

In the organisms describtion the scale will be depicted by size range, tolerance and habitat - Example: S-M (L)(F), which shows an organism ranging in size from small (S) to medium (M), has a low tolerance (L) and lives is fast (F) aqautic environments.


Additional Information

  • Food Web

    Functional feeding groups are a classification approach that is based on behavioral mechanisms of food acquisition rather than taxonomic group. The same general behavioral mechanisms in different species can result in the ingestion of a wide range of food items.

  • Tolerance

    Stress tolerance is the organism's ability to withstand a certain amount of anthropogenic influences. The index range for each category is based upon a (0-10) scale. For example, invertebrates with a low tolerance need adequate dissolved oxygen and chemical and physical stability, while those with a high tolerance can survive for a period of time when dissolved oxygen levels are less than adequate or other disturbances may be present.