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**Mayfly Genus Caenis (Angler's Curses)**

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Caenidae (Angler's Curses)

» Genus Caenis (Angler's Curses)

Species in Caenis
Caenis amicaAngler's Curse	0	0
Caenis hilarisAngler's Curse	0	0
Caenis latipennisAngler's Curse	0	0
Caenis tardataAngler's Curse	0	0
Caenis youngiAngler's Curse	0	0

7 species aren't included.

Common Names

Match	Common Name
	Angler's Curses
	Little White Spinners
	Little White Mayflies
	Tiny White-Winged Curses
	White-Winged Sulphurs

Pictures Below ↓

When the important hatches of Tricorythodes were first discovered by anglers, Caenis was given the credit. We now know that the Caenis mayflies are a different group, smaller and less common in trout streams, and they hatch in the evening instead of the morning.

They very rarely elicit selective feeding, but when they do they're very tough to match because they're often much smaller than size 28. This difficulty has earned them the nickname "Angler's Curse."

Where & When

Time Of Year (?): June through early September; best in June and July

Preferred Waters: Rivers and lakes

Most Caenis mayflies emerge in the evenings when other, larger mayflies are abundant on the water. This limits their importance.

Hatching Behavior

Caenis mayflies typically emerge, molt into spinners, mate, and oviposit within one hour.

Nymph Biology

Substrate: Silt, weeds

Every book says pools and stagnant back-waters are the prime habitats of these nymphs. This is probably true, but I have often found them in gravel, vegetation, and other habitats. They have operculate (

The operculate gills of a Caenis nymph.

Operculate: Lidlike; usually used to describe the pair of enlarged elytroid gills (called the operculum) which some silt-dwelling mayfly nymphs like Caenis and Eurylophella have developed to shield their other gills from debris.) gills adapted to survival on silty bottoms.

Pictures of 11 Mayfly Specimens in the Genus Caenis:

Specimen Page:12

Caenis (Angler's Curses) Mayfly Nymph

View 4 PicturesI confirmed the identity of this nymph by looking at it under a microscope to be certain of the shape of its gills and head.

Collected January 31, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Caenis (Angler's Curses) Mayfly Nymph

View 3 PicturesThis interesting little Caenis nymph is way darker than any of the others I collected in January 2004, probably a different species. It also has shorter tails.

Collected January 31, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Caenis (Angler's Curses) Mayfly Nymph

View 3 Pictures

Collected February 7, 2004 from unknown in Wisconsin
Added to Troutnut.com by Troutnut on January 25, 2006

Specimen Page:12

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Jargon Defined:

Molt: When aquatic insects with hard exoskeletons (like mayfly and stonefly nymphs) grow bigger, their exoskeleton does not grow with them. Instead they grow a new, larger one underneath and shed the old one when it's too small. This process is called molting.

Nymphs: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

The operculate gills of a Caenis nymph.

Oviposit: To lay eggs.

Useful References:

Arbona, Fred Jr. 1989. Mayflies, the Angler, and the Trout. Nick Lyons Books.

Caucci, Al and Nastasi, Bob. 2004. Hatches II. The Lyons Press.

Knopp, Malcolm and Robert Cormier. 1997. Mayflies: An Angler's Study of Trout Water Ephemeroptera . The Lyons Press.

Leonard, Justin W. and Fannie A. Leonard. 1962. Mayflies of Michigan Trout Streams. Cranbrook Institute of Science.

Schwiebert, Ernest G. 1955. Matching the Hatch. MacMillan Publishing Company.