Home Map FAQ Flyfishing Entomology
 

Forum



Replies Display
Topic: Mayfly - Attenella delantala - nymph
TaxonFeb 19, 2011 15:11 0024-0001

WA, USA

Topics started: 127
Replies made:  623

This mayfly nymph was captured in a kick-net sample at Cavanaugh Pond Natural Area County Park on the Cedar River south of Renton, WA, on June 4, 2010. Can you identify it to family, genus, and species?


Roger Rohrbeck
EntomanFeb 20, 2011 23:46 0024-0002

Northern California

Topics started: 55
Replies made:  783
Hi Roger,

Are the cerci vestigal or broken?

Kurt
Entoman
TaxonFeb 21, 2011 11:09 0024-0003

WA, USA

Topics started: 127
Replies made:  623

Kurt-

Here is another crummy photo, but it which shows the tails better.


Roger Rohrbeck
EntomanFeb 24, 2011 20:10 0024-0004

Northern California

Topics started: 55
Replies made:  783
Hi Roger,

Unique color Phase of E. dorothea infrequens or possibly excrucians. The combination of ebony and ivory is striking... Too bad the pictures didn't turn out better.

Regards,

Kurt
Entoman
TaxonFeb 24, 2011 22:18 0024-0005

WA, USA

Topics started: 127
Replies made:  623
Kurt-

Right family, wrong genus. Want another hint? It's one of the (3) species of that genus that you have in N. Calif, and the coloration is typical for that species.


Roger Rohrbeck
EntomanFeb 25, 2011 15:05 0024-0006

Northern California

Topics started: 55
Replies made:  783
Roger,

You're right, I should have included Attenella (found one described in a document sounding like yours called habitus?) in my list of possibles because of the skinny legs (which rules out Drunella). Lack of dorsal stripe probably rules out Serratella as well, which are usually more slender anyway. Personally, I've never collected a specimen like this (that I remember), or even seen a picture of them until now (assuming the ID). Nor have I seen an Ephemerillid with anywhere near the starkness in the banding on the abdomen as your two specimens display. I should still get some points though, since it is a pretty fuzzy photo.

Regarding your hint, which survey are you going by? Example: USGS, Cal (Berkley) Entomology Dept., disagree with each other in more than a few cases, and neither have a genus listed with three species in NorCal.

BTW, Ephemerellids have shown the trait of considerable differences in color and pattern deviation depending on substrate or vegetation. Chameleons of the order... This is why I'm leery of making determinations based on color or pattern as primary indicators. I've collected D. coloradensis and grandis that looked like somebody laid a straight edge across the middle of their wingcases and painted 'em a contrasting cream color! Also, what I believe to be the same species of Ephemerella in three different color phases (dk. chocolate, olive, cinnamon) from the same river. Interesting topic to sort out.

Regards,

Kurt
Entoman
TaxonFeb 25, 2011 16:25 0024-0007

WA, USA

Topics started: 127
Replies made:  623
Kurt-

The baseline for N. American mayfly state and province distribution which I use is from the PhD dissertation, Distribution of mayfly species of North America, by R.P. (Pat) Randolph, formerly of Mayfly Central. Its state and province distribution tables were hosted for some years by BugLab, but disappeared about a year ago when their website underwent a major overhaul. Pat Randolph listed the following Attenella species for CA: A. attenuata, A. delantala, and A. soquele. The specimens in my photos are A. delantala.


Roger Rohrbeck
EntomanFeb 25, 2011 17:12 0024-0008

Northern California

Topics started: 55
Replies made:  783
Hi Roger,

Habitus? That's a typo on my part, there's no such thing. Lists... Often a ticket to Frustrationville. I have no idea why margarita was left off the list, because we do have them here. BTW, look what I found! http://www.dfg.ca.gov/abl/lab/CA_digital_ref_level1_Attenella.asp

Kurt
Entoman
TaxonFeb 25, 2011 18:57 0024-0009

WA, USA

Topics started: 127
Replies made:  623
Hi Kurt-

The photos in the link you provided were labeled as attenella_habitus (right click / Save Image As). I believe ''habitus'' was being used to indicate physical appearance, rather than a species name, but then again, what the heck do I know?


Roger Rohrbeck
EntomanFeb 26, 2011 02:30 0024-0010

Northern California

Topics started: 55
Replies made:  783
Hi Roger,

Confusing! Found the ''name'' in a pdf of a paper that described your specimens color bands and wrote the post. Went to look for it again after you answered with delantala but couldn't find it. But I did find the photo I linked for you (which is remarkably similar to your specimens) by searching the CA DFG site. The picture is labeled simply Attenella genus with no reference to ''habitus'' or any other species. Can't find habitus on the site or by the method you mentioned because my apple mouse can't ''right click'' nor does it have a ''save as'' function on its edit menu. Weird that you found the name in the picture title. Anyway, it was my mistake and not a species name. Can't find it on any species list. You are right that it does mean general form and appearance. The term is often used referring to an illustration showing the whole form or appearance of a particular taxon. I guess the term can be applied to a photo too.
Pat Randolph listed the following Attenella species for CA: A. attenuata, A. delantala, and A. soquele.
Interesting that he excluded margarita and included attenuata. I thought attenuata was an eastern species?

Regards,

Kurt
Entoman
TaxonFeb 26, 2011 09:42 0024-0011

WA, USA

Topics started: 127
Replies made:  623
Kurt-
Ephemerellidae
Attenella attenuata (McDunnough)
    Canada—BC,NB,NS,ON,PQ.
    USA—AL,AR,CA,CT,FL,GA,IN,KY,MA,ME,MI,
    MO,NC,NY,PA,SC,VA,WI.
Attenella delantala (Mayo)
    USA—CA,ID,OR,WA.
Attenella margarita (Needham)
    Canada—AB,BC,NB,NS.
    USA—CO,CT,ID,ME,MI,MN,MT,NH,NM,NY,OR,UT,WA,WY.
Attenella soquele (Day)
    USA—CA,OR.

Yes, according to Pat Randolph, Attenella attenuata has an eastern distribution with the exceptions of BC and CA.


Roger Rohrbeck
EntomanFeb 26, 2011 16:55 0024-0012

Northern California

Topics started: 55
Replies made:  783
Roger - Well, maybe I'm wrong about margarita. But if so, I'm in the company of a lot of fishermen and several scientists that have documented the existence and importance of margarita in Lassen and Shasta counties of California for years. Most notably, Fall River and Hat Creek among many others. Take your pick of angling entomology's for confirmation. It has to come from somewhere. As I've said before, I'm not sure species lists and distribution charts are as dead-on accurate as we hope.

All I know is that I've been happily fishing over what I've assumed were margarita hatches for years. Gorgeous little bright green w/ yellow highlighted bodies and med. dun wings with more bluish tint than exhibited in any other Ephemerellid or Baetid (they are often confused with D. flavelina which are more olive and ringed with contrasting body color like their bigger brothers). Fading to a duller color quickly upon emergence (a trait shared with the other Ephemerellids), seems to be even more accelerated with this genus. It's rare to find a photo that does them justice, as most have faded to a dull or even dark olive by then.

Anyway, guess I've got to start calling them ''Blue Winged Olives'' until this is resolved.

Regards,

Kurt
Entoman
EntomanFeb 26, 2011 21:26 0024-0013

Northern California

Topics started: 55
Replies made:  783
Hi Roger - As much as I distrust lists, perhaps the most reliable source for updated mayfly names and regional distribution is Mayfly Central of Purdue University? They seem to take their website very seriously with constant updating. Frankly, they make Cal look like they're stuck in the mud. Anyway, here's their list of Attenella names and distribution:

# Attenella attenuata (McDunnough), 1925 [CAN:NE;USA:NE,SE]

* Ephemerella attenuata McDunnough, 1925 (orig.)
* Ephemerella hirsuta Berner, 1946 (syn.)

# Attenella delantala (Mayo), 1952 [USA:NW,SW]

* Ephemerella delantala Mayo, 1952 (orig.)

# Attenella margarita (Needham), 1927 [CAN:NE,NW;USA:NE,NW,SE,SW]

* Ephemerella margarita Needham, 1927 (orig.)

# Attenella soquele (Day), 1954 [USA:NW,SW]

* Ephemerella soquele Day, 1954 (orig.)

BTW, we've left poor little soquele out of our discussions. Assuming that we have the differences between margarita and delantala worked out, what about soquele? Current thought is that it's much wider spread than previously thought. George Edmunds cited populations throughout our western mountains to greater or lesser degree. I suspect they can be easily confused with margarita.

Regards,

Kurt
Entoman
TaxonFeb 26, 2011 22:40 0024-0014

WA, USA

Topics started: 127
Replies made:  623
Kurt-

Okay, let's discuss them. Jeff Adams (jaws on this forum) describes Attenella soquele distribution as: central OR Cascades to central CA Sierras. And, goes on to say:
Attenella soquele is uncommon and unlikely in standard macroinvertebrate samples in the Northwest. It is very similar to Attenella margarita, but is separated geographically (with some overlap around the southern end of the Willamette Valley.

Attenella soquele has fairly well developed, strongly pointed tubercles on abdominal segments 1- or 2-9. Attenella margarita also has pointed tubercles, but they will be quite small and not as sharp. The color pattern is probably a little lighter than that of Attenella margarita, but is still a prominent contrast between dark and light. Like other Attenella, they don't have a disk of hairs on the underside of the abdomen; all their femora and tails are similar; their gills start on abdominal segment 4; and all the gills are similar in size.

So, it seems A. soquele could easily be mistaken for A. margarita, particularly by a fly fisher lacking the degree of taxonomic obsession which you and I appear to share. What do you think?



Roger Rohrbeck
EntomanFeb 27, 2011 12:24 0024-0015

Northern California

Topics started: 55
Replies made:  783
Roger - I'm going to have to collect some fresh samples of Attenella's this spring to re-verify that what I thought I was thinking should still be thunk. That's what I think. Heck, I'm not even safe from possible attenuata incursions as once believed according to reputable sources you've provided. I seem to remember capturing lighter, more olivaceous specimens, but assumed they were just variations within the same species (a trait common in other Ephemerellids). Not so sure now. I've got some tubercles to inspect!

It looks like you might be safe from this confusion up there. But who knows? Dr. Edmunds said ''Western Mountains'' which could mean anywhere from Southern New Mexico to the Cascades near the Canadian border. I think he was trying to illustrate the point that Day's discovery was more widespread than California's Central Coast and probably shouldn't be taken too literally. However, if I were a betting man, I'd put my money on soquele's range being analogous to the Black Tail deer? Primarily coastal with incursions inland under the right conditions. As is the case with Blacktails and Mulies, cohabitation probably takes place here and there, and waters I often fish are prime suspects.

Kurt
Entoman
TaxonMar 28, 2011 01:56 0024-0016

WA, USA

Topics started: 127
Replies made:  623
Kurt-
I'm going to have to collect some fresh samples of Attenella's this spring to re-verify that what I thought I was thinking should still be thunk.
I look forward to your sharing what you learn. Be sure to take some photos.


Roger Rohrbeck


Created: 01/12/2010   Last modified: 12/26/2014    www.FlyfishingEntomology.com