Mayflies are fascinating insects known for their unique life cycle. These delicate creatures play a vital role in ecosystems, contributing to nutrient cycling and serving as food for various predators. The life cycle of a mayfly comprises several stages, including the egg, larval (nymph), subimago, and adult (imago) stage1. Each stage plays a crucial role in the overall development and reproduction of the mayfly.
Mayfly eggs are laid on water surfaces, where they quickly sink to the bottom before hatching into aquatic nymphs[^2^]. These nymphs, also known as naiads, can live underwater for months to years, breathing through gills while foraging on organic debris and algae[^3^]. Once the nymphs are ready to emerge, they transform into subimagos – an active, mobile phase unique to mayflies.
Life Stages of the Mayfly
Nymph
- Mayfly nymphs, also known as naiads, live underwater for months to years.
- They crawl around rocks and vegetation, feeding on organic matter.
Subimago
- The subimago stage is unique to mayflies among extant insects.
- It is an active and mobile stage between the ultimate larval instar and the mature adult stage (imago).
Imago
- Mayflies are the only insects to have two “adult” molts, reaching the imago stage after passing through the subimago stage.
- Imago mayflies have a short life span, lasting only a few minutes to a few days depending on the species, with the sole purpose of mating before they die.
Comparison table:
| Stage | Duration | Habitat | Unique features |
|---|---|---|---|
| Nymph | Months to years | Underwater, around rocks and vegetation | Feeds on organic matter |
| Subimago | Between nymph and imago | Transitioning from underwater to above water | Active and mobile stage |
| Imago | Few minutes to few days | Above water, mates and then dies | Two “adult” molts, short lifespan |
Habitat
Rivers and Streams
Mayfly larvae, also known as nymphs, are commonly found in rivers and streams. They often have flattened heads which help them adhere to rocks in fast-flowing water1. Some specific characteristics of mayfly nymphs in rivers and streams include:
- Sharp claws: Nymphs have sharp claws for clinging onto rocks and stones.
- Gills: They have leaf-like or feathery external gills for breathing underwater.
Ponds and Lakes
Although less common, some species of mayflies can thrive in ponds and lakes1. The primary differences in the habitats may affect the nymphs’ features and behaviors:
| Rivers and Streams | Ponds and Lakes |
|---|---|
| Fast-flowing water | Slow-moving or still water |
| Flattened head for adhering to rocks | May have a less flattened head |
| Sharp claws for clinging to rocks | Less need for sharp claws |
In these environments, mayfly nymphs may display different adaptational traits:
- Swimming: Nymphs in ponds and lakes may be better adapted for swimming than their river-dwelling counterparts.
- Depth preferences: They may prefer different depths, depending on the available resources and water conditions.
Ecological Significance
Importance in Ecosystem
Mayflies play a vital role in the ecosystem. They serve as an essential food source for various predators like fish, birds, and amphibians. Some examples of animals that feed on mayflies include:
- Trout
- Bass
- Frogs
- Dragonflies
Pros of mayflies in the ecosystem:
- Contribute to the food chain
- Help recycle nutrients in aquatic ecosystems
Cons of mayflies in the ecosystem:
- Mayfly swarms can cause inconvenience for humans, especially near rivers or lakes
Indicator of Water Quality
Mayflies are considered an excellent indicator of water quality. A healthy population of mayflies can signal good quality water and a well-functioning ecosystem. On the other hand, the absence or decline of mayflies may suggest water pollution or degraded habitat.
| Water Quality | Mayfly Population |
|---|---|
| Good | Healthy, abundant |
| Poor | Declining, absent |
In conclusion, mayflies serve as important components of the ecosystem and help us assess water quality, contributing to the overall health of our environment.
Footnotes
6 Comments. Leave new
Hi Daniel: This naiad appears to have three tails (cerci) not two, which would make it a mayfly. It looks lake a “clinger” mayfly (Ephemeroptera: Heptageniidae), possibly in the genus Maccaffertium. You could also check out Stenonema which look very similar, but most of the species in this genus have recently been moved to Maccaffertium or Stenacron. The Heptageniidae are well known to fly fishers and include the popular March Brown (Maccaffertium [=Stenonema] vicarium) and Cahills. Regards. K
Hey, this is Tyler (I emailed you), this is a great picture of a subimago mayfly
Hi Tyler,
We received your earlier request: “hello, I am a student at the University of Wisconsin LaCrosse and am currently making an informational website about mayflies. I am emailing you to ask permission to use one of your mayfly images on my webpage which will be viewable to the public. The image will be referenced back to your webpage and will remain online as a part of a larger project: multiple organisms.net
I would appreciate it thanks.”
You have our permission to use this image since it will not be a commercial use and it will be for educational purposes.
I believe these are all actually mayfly nymphs, the first two appearing to have 3 tails and belonging to the family Ephemerellidae, or spiny crawlers. If you look closely you can see plate-like gills along the sides of the abdomen. The third is also a mayfly, but a 2-tailed variety, appearing to belong to the family Heptageniidae, or flat-head family.
Mayflies: tasty!
Dave
http://www.smallstockfoods.com
It looks like an extremely small daffodil. Photoshop, anyone?