Mayfly Genus Penelomax

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Ephemerellidae (Hendricksons, Sulphurs, PMDs, BWOs)

» Genus Penelomax

Species in Penelomax
Penelomax septentrionalis	3	25

Pictures Below ↓

This recently minted genus contains a single, very distinctive species, Penelomax septentrionalis. Visit that page for information.

Pictures of 3 Mayfly Specimens in the Genus Penelomax:

Penelomax septentrionalis Mayfly Nymph

View 12 PicturesThis is surely the most distinctive-looking species in Ephemerellidae. I like the rugged, spindly look. If mayflies made movies, Penelomax septentrionalis would probably play the supervillain.

Maybe I should take a break and get something to eat.

Collected May 13, 2007 from the Delaware River in New York
Added to Troutnut.com by Troutnut on May 18, 2007

Female Penelomax septentrionalis Mayfly Dun

View 10 PicturesI'm confident this dun belongs to septentrionalis, because her legs are just too long for any other Ephemerellid, and her unusual mid-dorsal (Dorsal: Top.) stripe matches those of two easily identified nymphs I collected some miles downstream.

This really pretty mayfly was in kind of bad shape when I found it crippled on the surface, and bouncing around in my container with a bunch of green drakes didn't help.

Collected June 1, 2007 from the West Branch of the Delaware River in New York
Added to Troutnut.com by Troutnut on June 4, 2007

Penelomax septentrionalis Mayfly Nymph

View 3 Pictures

Collected May 13, 2007 from the Delaware River in New York
Added to Troutnut.com by Troutnut on May 18, 2007

Recent Discussions of Penelomax

Anyone know more about Ephemerella septentrionalis? 11 Replies »

Posted by Troutnut on May 18, 2007 in the species Penelomax septentrionalis

Last reply on Jul 18, 2011 by Oldredbarn

I found about one sentence on these in Gonzo's book, and haven't seen them mentioned anywhere else in fly fishing literature. Nor is any of the scientific literature I have on them particularly interesting (just descriptions). Now that I've collected a few and see what unique-looking nymphs they've got, I'm really curious about them.

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Jargon Defined:

Dorsal: Top.

Dun: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.

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).