SPECIES ID / Invertebrates

True Flies

Shore Flies/Brine Flies

Pxwíqs

  • 445 species in North America
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Ephydridae

Identification Tips:

• Body length 1-14 mm
• Body form variable, but most commonly
• Cylindrical with front tapering to cone
• Head not visible, except hardened parts inside first body segment
• Pair of prolegs on each of 8 segments, with rear pair larger
• Sturdy tail-like extension from rear of body contains retractable breathing tube
• May be exceptionally abundant in some places

Life History:

• Different species found in all aquatic habitats including salt marshes
• Also alkaline lakes, salt lakes, hot springs, and tar pits
• Larvae often found burrowing in algae mats or plant debris on shores
• Consume plant material, bacteria, fungi algae and decaying organic matter

• Pupae float with tubes projecting above the surface for breathing air
• Important in diet of shorebirds, waterfowl and other species

POLLUTION TOLERANCE
Very Sensitive Somewhat Sensitive Facultative Somewhat Tolerant Very Tolerant
    Most Some Some

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Primary Information Source:
Voshell, J. Reese. 2002. A Guide to Common Freshwater Invertebrates of North America. McDonald and Woodward Publishing Company. Blacksburg, Virginia.