The Majestic Mayfly

Mayflies may be one of the most recognizable shapes around freshwater environments. Even if you may not have known what they were called, their long tails make them quite distinct and memorable. Mayflies are a great indicator species for clean streams and rivers, and they often serve a model species for fly-fishing lures. Most mayfly species lay their eggs after mating and eggs will develop in the stream for 10 days, for up to months before hatching. This unique species, Cloeon cognatum is ovoviviparous – meaning they carry their eggs internally until right before they are ready to hatch before the are laid into the stream. This has the large benefit of being able to protect their offspring while they are in the most vulnerable state. Although rarely seen in Canada, this species can be found across Europe, Asia and in the Southern USA. This Video is showing egg laying and hatching in real time!

Video Source: Stroud Water Research Centre, 970 Spencer Road Avondale, PA 19311 USA
Cordillera does not own any rights to this video.