Cyprinella hybrids?
#1 Guest_Uland_*
Posted 12 July 2011 - 09:01 AM
Scott, Blake and I managed to get out over the weekend and photographed quite a few fish.
We found C. spiloptera and C. Lutrensis together. This particular location is usually has a C. lutrensis population that vastly outnumbers C. spiloptera (rarely see any spiloptera) but this day we found many and a few odd fish which I suspect might be hybrids.
I honestly don't see what I think might be hybrids often and wonder if in this case I'm being a bit sensitive and simply seeing atypical variation.
All below photos taken on the same day from the same river.
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1 805.JPG 39.22KB 1 downloads
#2 Guest_gerald_*
Posted 12 July 2011 - 11:15 AM
#3 Guest_jblaylock_*
Posted 13 July 2011 - 05:15 PM
#4 Guest_Skipjack_*
Posted 13 July 2011 - 08:51 PM
#5 Guest_rjmtx_*
Posted 13 July 2011 - 09:19 PM
#6 Guest_Uland_*
Posted 13 July 2011 - 09:56 PM
Gerald...Is it known why/how C. lutrensis so easily/readily hybridize and furthermore where introduced out of native range? Inquiring minds want to know!
Both C spiloptera and C. lutrensis are native to this river (Vermilion River Illinois River Drainage). Seems like north central Illinois is a battleground for the two as I don't think I've ever encountered a stream where the two were equally divided but my experience is limited....so many streams - such little time.
Robby, this river is pretty clean actually - well as far as northern Illinois is concerned but a cement plant is located upstream along with a low head dam....I have to check that dam out one of these days.
I guess I really don't know how to go about providing with any level of certainty you've found a hybrid minnow in the field. I see collection records regularly report "cyprinella hybrid" or some other genus and wonder how one can make such a determination in the field.
#7 Guest_farmertodd_*
Posted 14 July 2011 - 09:37 AM
The "pollution" can be as simple as homogenization. There is a good amount of literature on the effects of lutrensis introductions. I don't have citations on hand, but I did a quick look at Google Scholar and that will get you in business if interested.
Todd
Edited by farmertodd, 14 July 2011 - 09:38 AM.
#8 Guest_gerald_*
Posted 14 July 2011 - 10:04 AM
In NC none of our native Cyps have red on the sides or fins (execpt red tail on fieryblack) so when I see red where it shouldn't be and deep body shape, I assume lutrensis hybrid. I have never seen apparent hybrids of any of our native Cyps, but have seen several obvious hybrids of chub-nest spawners in other genera (Phoxinus x Clinostomus, Notropis chlorocephalus x Clinostomus, Luxilus x Nocomis).
#9 Guest_travishaas_*
Posted 14 July 2011 - 10:58 AM
Travis
#10 Guest_blakemarkwell_*
Posted 14 July 2011 - 12:46 PM
Additionally, this population is heavily skewed towards C. lutrensis. Any given day, you sample about 250-1000 C. lutrensis per 1 C. spiloptera. Therefore the rarer C. spiloptera eggs probably have a greater chance of running into the milt of heterspecifics (C. spilotpera) than conspecifics. The "pollution" would only exacerbate the poorly defined prezygotic RIMs (both crevice spawners during summer) among the Cyprinella.
Blake
Edited by blakemarkwell, 14 July 2011 - 12:48 PM.
#11 Guest_fundulus_*
Posted 14 July 2011 - 01:18 PM
#12 Guest_blakemarkwell_*
Posted 14 July 2011 - 02:19 PM
Edited by blakemarkwell, 14 July 2011 - 02:23 PM.
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