Hex Mayflies
Hexagenia limbata
The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
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Millcreek on Jul 20, 2014July 20th, 2014, 12:58 pm EDT
Yeah, I know the likelihood of getting these IDed to species is unlikely, but I thought I'd see if anyone has any ideas.
Meyer and McCafferty list twenty species of Ameletus occurring in California (Mayflies of California 2008) but these are apparently identified from nymphs which seems unlikely since there is no key for Ameletus nymphs of California. The only key I'm aware of which sorta/kinda covers western Ameletus nymphs is Zloty and Pritchard's key to Alberta nymphs (1999) and it doesn't cover a number of the species listed by Meyer and McCafferty.
Species #1 is the most common of the three and can be found from early January through mid March. #2 is fairly common and is found from late February through mid March and #3 was found in late March and is uncommon. Measurements are below each picture.
Any ideas or additional information would be appreciated.
Meyer and McCafferty list twenty species of Ameletus occurring in California (Mayflies of California 2008) but these are apparently identified from nymphs which seems unlikely since there is no key for Ameletus nymphs of California. The only key I'm aware of which sorta/kinda covers western Ameletus nymphs is Zloty and Pritchard's key to Alberta nymphs (1999) and it doesn't cover a number of the species listed by Meyer and McCafferty.
Species #1 is the most common of the three and can be found from early January through mid March. #2 is fairly common and is found from late February through mid March and #3 was found in late March and is uncommon. Measurements are below each picture.
Any ideas or additional information would be appreciated.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
-Albert Einstein
Taxon on Jul 20, 2014July 20th, 2014, 2:10 pm EDT
Hi Mark-
Nymphal keys, nymphal descriptions, and distribution of (12 of the 20) California Ameletus species appear in Zloty J; Pritchard G. 1997. Larvae and adults of Ameletus mayflies (Ephemeroptera: Ameletidae) from Alberta. Canadian Entomologist 129:251-289.
Nymphal keys, nymphal descriptions, and distribution of (12 of the 20) California Ameletus species appear in Zloty J; Pritchard G. 1997. Larvae and adults of Ameletus mayflies (Ephemeroptera: Ameletidae) from Alberta. Canadian Entomologist 129:251-289.
Millcreek on Jul 20, 2014July 20th, 2014, 2:36 pm EDT
Roger -
Thanks, I was aware of that reference (though I seem to have gotten the publication date wrong). I'll probably go back to it and give it another try.
I'm just a little leery about trying to ID a species using a key that doesn't have 8 of the 20 (more or less) possibilities in it.
The only key I'm aware of which sorta/kinda covers western Ameletus nymphs is Zloty and Pritchard's key to Alberta nymphs (1999) and it doesn't cover a number of the species listed by Meyer and McCafferty.
Thanks, I was aware of that reference (though I seem to have gotten the publication date wrong). I'll probably go back to it and give it another try.
I'm just a little leery about trying to ID a species using a key that doesn't have 8 of the 20 (more or less) possibilities in it.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
-Albert Einstein
Entoman on Jul 20, 2014July 20th, 2014, 3:25 pm EDT
Hey Mark,
Yes, the painted minnow nymphs/brown duns is another group that is very difficult to nail down. The good news is that maculation patterns (especially tail banding) are still believed to be valid taxonomic characters for species identification, at least as far as I can tell. The bad news is these characters have gone unreported (at least in the public realm) for a good number of the species. If any of your specimens match up in the Zloty keys pretty well, I'd go with that. The fact that many are missing from the keys is not a detriment in this unless future studies prove to show that maculation patterns are unreliable.:)
BTW - the same problem of species ID dificulties exist for our leptophlibids and even many of our ephemerellids as well, albeit for different reasons.
Yes, the painted minnow nymphs/brown duns is another group that is very difficult to nail down. The good news is that maculation patterns (especially tail banding) are still believed to be valid taxonomic characters for species identification, at least as far as I can tell. The bad news is these characters have gone unreported (at least in the public realm) for a good number of the species. If any of your specimens match up in the Zloty keys pretty well, I'd go with that. The fact that many are missing from the keys is not a detriment in this unless future studies prove to show that maculation patterns are unreliable.:)
BTW - the same problem of species ID dificulties exist for our leptophlibids and even many of our ephemerellids as well, albeit for different reasons.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Crepuscular on Jul 21, 2014July 21st, 2014, 6:05 am EDT
Good luck with these specimens. ;) But they sure are beautiful critters. Like you Mark, I have to wonder how Meeyer and McCafferty keyed those specimens out. I have run into the same issues here in PA with Ameletus sp. nymphs. And the ephemerellids...
Oldredbarn on Jul 21, 2014July 21st, 2014, 7:36 am EDT
Good luck with these specimens. ;) But they sure are beautiful critters. Like you Mark, I have to wonder how Meeyer and McCafferty keyed those specimens out. I have run into the same issues here in PA with Ameletus sp. nymphs. And the ephemerellids...
Ok boys! Especially Eric...Lay the cane rods down and get to work and add to the keys...Your boots are on the ground...We have discussed here before, the boys in Purdue are few, and they're stretched...Let's do some Citizen Science. :)
Spence
Oh...by-the-way...I'm going fishing. :)
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively
"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Millcreek on Jul 21, 2014July 21st, 2014, 12:18 pm EDT
I've begun to try to key these out using Zloty and Pritchard. So far I've only attempted #1 and it seems to key to Ameletus velox. Since I'm not playing with a full deck (a complete key) I wouldn't swear to it but I think it's as close as I'll get.
Kurt - Not so sure about tail banding on the nymphs, The specimens I have show quite a bit of variation among what seem to be the same species otherwise. Also seem to vary according to what stage of maturation the nymph is.
Eric - I agree, they're gorgeous little animals. One of my favorite nymphs to see each year. And yeah, it would be nice if Meyer and McCafferty gave more of an explanation as to how they arrived at their IDs. Possibly unpublished data available to them I suppose.
Spence - Left you an opening there about not playing with a full deck of cards.
Kurt - Not so sure about tail banding on the nymphs, The specimens I have show quite a bit of variation among what seem to be the same species otherwise. Also seem to vary according to what stage of maturation the nymph is.
Eric -
But they sure are beautiful critters.
Spence - Left you an opening there about not playing with a full deck of cards.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
-Albert Einstein
Oldredbarn on Jul 21, 2014July 21st, 2014, 1:45 pm EDT
Spence - Left you an opening there about not playing with a full deck of cards.
Mark...We all are suspect on this site! :) Bug obsessed, every damn one of us!
See my latest post...Pre-western trip...Need I say more?
Spence
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively
"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
Entoman on Jul 21, 2014July 21st, 2014, 5:00 pm EDT
Mark,
Perhaps you're right about the tails. Should have mentioned that I was quoting Zloty about their taxonomic significance. Personally, I haven't a clue... :)
Hey Eric - Didn't we look at a few of yours that left us puzzled a few years ago?
Perhaps you're right about the tails. Should have mentioned that I was quoting Zloty about their taxonomic significance. Personally, I haven't a clue... :)
Hey Eric - Didn't we look at a few of yours that left us puzzled a few years ago?
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Crepuscular on Jul 21, 2014July 21st, 2014, 5:38 pm EDT
Hey Eric - Didn't we look at a few of yours that left us puzzled a few years ago?
Yeah I think so. I can't remember but I think
It may have been Ameletus ludens. http://www.troutnut.com/topic/7836/Ameletus#35552
Entoman on Jul 21, 2014July 21st, 2014, 6:22 pm EDT
Yep, that's the one! What a beauty.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
Millcreek on Jul 22, 2014July 22nd, 2014, 8:35 pm EDT
Eric - That is a little beauty. Was it in a tank or were the photos taken underwater?
To all - I went back to Zloty and Pritchard and using their key for Alberta Ameletus nymphs I come up with;
#1 - Ameletus velox
#2 - Ameletus subnotatus
#3 - Ameletus validus
Some differences in maculation but the nymphs vary according to how mature they are and also to a certain extent in mature nymphs I've collected. Plus we're not in Alberta.
Mouthparts and presence or absence of serrations on the margins of the sternites and posterolateral spines or absence of them all matched. Would I bet the farm on it? No, but given the info I have the IDs seem probable.
Mark
To all - I went back to Zloty and Pritchard and using their key for Alberta Ameletus nymphs I come up with;
#1 - Ameletus velox
#2 - Ameletus subnotatus
#3 - Ameletus validus
Some differences in maculation but the nymphs vary according to how mature they are and also to a certain extent in mature nymphs I've collected. Plus we're not in Alberta.
Mouthparts and presence or absence of serrations on the margins of the sternites and posterolateral spines or absence of them all matched. Would I bet the farm on it? No, but given the info I have the IDs seem probable.
Mark
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
-Albert Einstein
Crepuscular on Jul 25, 2014July 25th, 2014, 3:34 am EDT
Eric - That is a little beauty. Was it in a tank or were the photos taken underwater?
I have a very small tank set up for underwater photography of live specimens.
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