Aquatic Macroinvertebrate
Identification
Kingdom Phylum Class Order Family Genus Species
Click on an Order below to learn more about their key characteristics.
Click on a picture in each Order gallery to learn more about Family level pollution tolerance and key characteristics.
*All photos on this page are provided by Rhithron Associates, Inc.
Check out an amazing interactive aquatic macroinvertebrate identification guide created by Macroinvertebrates.org and the National Science Foundation!
Ephemeroptera
Key Characteristics:
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Gills on abdomen
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2 or 3 cerci (tails)
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1 tarsal claw on each leg
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Wingpads on thorax
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No visible segments on thorax
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Plecoptera
Key Characteristics:
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Gills on thorax or not present
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2 cerci (tails)
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2 tarsal claws on each leg
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Long antennae
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Segmented thorax
Trichoptera
Key Characteristics:
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Hook, brush, or prolegs at end of abdomen
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Gills often on ventral or lateral abdomen
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No wingpads
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Antennae short or not visible
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Sclerotized head
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Soft, caterpillar-like abdomen
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Can be free living or cased
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Diptera
Key Characteristics:
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Soft, fleshy body
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Cylindrical in shape
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No segmented legs, may have prolegs
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Head small or not visible
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Generally the flashy end is the posterior end
Coleoptera
Key Characteristics:
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Sclerotized body
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Both adults and larvae may be aquatic
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Jointed legs
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No wingpads on larva
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Wings of adults modified into hardened, protective structure (elytra)
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Odonata
Key Characteristics:
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Long body with large head
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Damselflies have gills on the posterior end of abdomen
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Large, extendable lower jaw
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Wingpads on thorax
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Large eyes
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2 tarsal claws
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Megaloptera
Key Characteristics:
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Large gills along side of body
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Large pincer mandibles
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Long filament or hooks at end of abdomen
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Eyes are a star shape
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Sclerotized head
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No wingpads
Hemiptera
Key Characteristics:
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Needle-like beak
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Patterned or leathery textured back
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Or long slender body with long legs
Non-Insects
Key Characteristics:​
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No legs or more than 3 pairs of legs
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