Mayfly Family Heptageniidae (March Browns, Cahills, Quill Gordons)
Taxonomic Navigation -?-
Kingdom Animalia (Animals)
» Phylum Arthropoda (Arthropods)
» Class Insecta (Insects)
» Order Ephemeroptera (Mayflies)
» Family Heptageniidae (March Browns, Cahills, Quill Gordons)
| Genus in Heptageniidae |  |  |
| CinygmaWestern Light Cahills | 0 | 0 |
| CinygmulaDark Red Quills | 1 | 10 |
| EcdyonurusWestern Ginger Quills | 0 | 0 |
| EpeorusLittle Maryatts | 31 | 193 |
| Heptagenia | 4 | 18 |
| Ironodes | 0 | 0 |
| Leucrocuta | 8 | 47 |
| MaccaffertiumMarch Browns and Cahills | 57 | 270 |
| Nixe | 1 | 13 |
| Rhithrogena | 4 | 28 |
| StenacronLight Cahills | 8 | 48 |
| Stenonema | 1 | 6 |
4 genera aren't included.
Common Name
| Match | Common Name |
 | March Browns, Cahills, Quill Gordons |
Heptageniidae can be broken into "groups" of similar genera to help the angler keep track of them. Although many of them contain closely related genera, they are not officially divided in this way by entomologists. Here are the groups:
Former Stenonema
The genus Stenonema now contains only one species, and its many former species are split between the newer genera Maccaffertium and Stenacron. These include the March Brown superhatch, Maccaffertium vicarium.
The former Stenonema species are mostly limited to the East and Midwest.
Former Heptagenia
While Heptagenia has held on to more species than Stenonema, many of its fishable hatches have been moved out to Leucrocuta, Nixe, and Ecdyonurus.
There are many former Heptagenia species across the continent, but they are far more important to fishermen in the West than in the East.
Two-tailed Nymphs
The closely related genera Epeorus and Ironodes are among the only mayflies to have just two tails as nymphs. They include the Eastern superhatch of Epeorus pleuralis, the Gordon Quills.
Suction Cups
The genus Rhithrogena is known for the gills of its nymphs. They extend below the abdomen in the front and the back and form a suction cup which helps the nymph cling to rocks. They can be very important but not very often.
Big Mouth Parts
The genera Cinygmula and Cinygma are marked by enlarged mouth parts which stick out to either side of the head a little ways. A few species produce fishable hatches, but none are of major significance.
Hatching Behavior
Many Heptageniid mayflies emerge from their nymphal shucks (
View Full Size
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
Nymph Biology
Heptageniidae contains the "clinger" type mayfly nymphs. They sport flattened profiles and strong legs suitable for life in very fast water. Some species have branched out from this role and are found in slow, warm, or even dirty streams, but they retain the flat bodies of their kin.122 Mayfly Specimens in the Family Heptageniidae:
Epeorus pleuralis (Quill Gordon) Mayfly Dun
View 9 PicturesI kept this specimen after photographing it and it molted into a spinner in perfect condition, which I photographed here.
View 9 PicturesI kept this specimen after photographing it and it molted into a spinner in perfect condition, which I photographed here.Region: Northeast
Collected Apr 30, 2007
Added May 3, 2007
Maccaffertium terminatum Mayfly Spinner
View 11 PicturesI positively identified this specimen under a microscope with a good key. It was one of the more common species in a generally light mixed bag of mayflies over a big Catskill tailwater last night.
I swooped this one out of the air while it was mating with a female, so I can be certain about her ID as well.
View 11 PicturesI positively identified this specimen under a microscope with a good key. It was one of the more common species in a generally light mixed bag of mayflies over a big Catskill tailwater last night.I swooped this one out of the air while it was mating with a female, so I can be certain about her ID as well.
Region: Catskills
Collected Jun 7, 2007
Added Jun 8, 2007
Epeorus pleuralis (Quill Gordon) Mayfly Spinner
View 10 PicturesA few days earlier I photographed this same specimen as a dun. The changes between dun and spinner seem particularly dramatic in this species.
View 10 PicturesA few days earlier I photographed this same specimen as a dun. The changes between dun and spinner seem particularly dramatic in this species.Region: Northeast
Collected Apr 30, 2007
Added May 3, 2007
6 Streamside Pictures of Heptageniidae Mayflies:
View Full Size
This Epeorus pleuralis nymph tried to hatch into a dun while attached to this rock and apparently got stuck. This species is supposed to emerge from its nymphal shuck (Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.) on the bottom of the stream and swim to the surface as a bedraggled dun. It seems more like this one was trying to crawl out onto a rock to emerge. The rock itself is covered with a thin layer of fast water in a riffle, and apparently it prevented the dun from making any headway. You can see the dun's eyes and a bit of the mesonotum (Mesonotum: The top of the insect mesothorax.) if you look closely.
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
Epeorus nymphs with their flat profile and wide gills are excellent at clinging to rocks in fast water. This one clings to the surface of a rock covered with only a thin layer of water rushing over it in a riffle.
In this picture: Mayfly Genus Epeorus (Little Maryatts).
In this picture: Mayfly Genus Epeorus (Little Maryatts).
A freshly hatched Quill Gordon dun looks out across the surface of the Catskill stream she just escaped.
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
11 Underwater Pictures of Heptageniidae Mayflies:
In this picture: Mayfly Genus Epeorus (Little Maryatts) and Mayfly Family Baetidae (Blue-Winged Olives).
In this picture: Mayfly Genus Epeorus (Little Maryatts) and Mayfly Family Baetidae (Blue-Winged Olives).
Recent Discussions of Heptageniidae
2 tails or 3 4 Replies »
Posted by Snagy on Feb 5, 2010 in the species Maccaffertium vicarium
Last reply on Feb 6, 2010 by Taxon
I notice that while the dun, nymph, and spinner photos on the page are all listed as March Brown (maccaffertium vicarium). While the coloration patterns all seem to follow other March Browns I have seen, I notice that the winged flies pictures all have 2 tails, but the nymphs in the photos have 3. I was under the impression this species was a 2 tailed mayfly. Is the nymph mislabelled?
Reply Heptageniidae Family breakup ??? 14 Replies »Posted by Quillgordon on Mar 21, 2009
Last reply on Mar 24, 2009 by GONZO
Looking at a recent photo of a possible 'march brown' nymph; this question came to mind!
What factors were involved in the making of the 'maccaffertium/stenacron/stenonema genera?
Can someone give me a link (general explanation, if possible) to explain the distinction of the insect in question.
Qg.
ReplyAdded more Heptagenia culacantha info 9 Replies »What factors were involved in the making of the 'maccaffertium/stenacron/stenonema genera?
Can someone give me a link (general explanation, if possible) to explain the distinction of the insect in question.
Qg.
Posted by Troutnut on Dec 19, 2006 in the species Heptagenia culacantha
Last reply on Jun 12, 2008 by GONZO
I went to the entomology library today and photocopied the 1985 paper that first described this curious species. I've updated the culacantha page with this information.
ReplyLink to pictures of H. culacantha 2 Replies »Posted by Troutnut on Oct 20, 2006 in the species Heptagenia culacantha
Last reply on Oct 4, 2007 by Troutnut
Many thanks to user Softhackle for digging up this link. I knew about the thread from back when it started, but I wasn't able to find it when I went back to look last night. Good work!
Fly Fisherman Magazine forum topic with two pictures of a H. culacantha dun.
I've added the species to the "live" part of the database and put up a rudimentary page where I can compile any more information we find.
ReplyAnybody know more about Maccaffertium terminatum? 3 Replies »Fly Fisherman Magazine forum topic with two pictures of a H. culacantha dun.
I've added the species to the "live" part of the database and put up a rudimentary page where I can compile any more information we find.
Posted by Troutnut on Jun 8, 2007 in the species Maccaffertium terminatum
Last reply on Jun 11, 2007 by Konchu
I just wrote up what I found on the page for this species. I was mildly surprised to see so many of a species I've never seen mentioned in an angling context -- at least a few dozen throughout the evening. They piqued my curiosity.
ReplyThere are 11 more topics.
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