SPECIES ID / Invertebrates


Small Minnow Mayflies

  • 130 species in North America
  • Some tolerant of pollution (unlike most other Mayflies)



Identification Tips:

• Antennae long; more than twice width of head
• Usually 3 tails; middle one often shorter; 2 tails in some species
• Rounded, plate-like gills on both sides of most abdominal segments
• Length 3-12 mm not including tails/antennae
• No spines at rear of abdomen
• Resting posture of deeply arched back common

Life History:

• Occur in a wide variety of flowing and standing water habitats
• May be very abundant in thick aquatic vegetation
• Tolerate wide range of temperatures
• Swim well by flexing abdomen
• Feed on collected or scraped organic debris and periphyton
• Most stream species spend winter as dormant eggs
• Most species produce 2 generations per year

Very SensitiveSomewhat SensitiveFacultativeSomewhat TolerantVery Tolerant

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