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Scuds or Side Swimmers (Amphipoda)

General Information about Scuds or Side Swimmers (Amphipoda)
Life history Scuds live their entire life in the water and usually live for only one year. Females carry the eggs in a pouch on the bottom of their body until the hatched eggs are about a week old.
Diversity There are about four families that include freshwater scuds or side swimmers in North America. Most kinds of scuds live in marine water.
Two pair of long antennae; body is flattened from side to side; 7 pairs of legs.
Habitat & Feeding Scuds or side swimmers may be found in lakes, ponds, streams, underground water and springs. Scuds are omnivores, feeding on both plant and animal material; usually decaying plant material and dead animal matter.
Water quality indicator status Most kinds of scuds are tolerant of pollution and environmental stress; however some kinds are sensitive to heavy metals and pesticides.
Fun facts
  • Scuds move in response to light; they generally avoid bright light and they are most active at night.
  • In waters without fish, the scud population can reach very high densities-up to 10,000 per square meter!

image of Crangonyctidae
Family: Crangonyctidae

image of Gammaridae
Family: Gammaridae