Troutnut.com Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

> > Strange Critter

PaulRobertsJuly 16th, 2016, 8:15 pm
Colorado

Posts: 1750
Filmed in a freshwater pond in Colorado. It is likely a larval...something...and appears to be around a bit under an inch (20mm) in length. It appears to be nearly transparent, long thread-like tails, and a smooth gliding swimming behavior. I took a wild stab at a Gastrotrich, but an expert in Italy, Antonoio Todara, didn't think so. "Too big", he thought.

It's not a very clear video so its best viewed small -like NOT full screen. Best guesses?
https://www.youtube.com/watch?v=sPpy4Yssmko
MillcreekJuly 17th, 2016, 3:17 pm
Healdsburg, CA

Posts: 291
Paul,

Maybe a water scavenger beetle? Something like these.

http://www.mdfrc.org.au/bugguide/display.asp?type=5&class=17&subclass=&Order=1&family=238&couplet=0

http://aquaticinsectsofcentralvirginia.blogspot.com/search?q=water+scavenger

The bottom link you'll have to scroll down to get to the water scavenger beetles.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
PaulRobertsJuly 19th, 2016, 3:26 pm
Colorado

Posts: 1750
Thanks, Mark. But... I don't think so. The transparency and slow gliding movement through open water is unique. I'm at a loss.
KonchuJuly 23rd, 2016, 10:11 pm
Site Editor
Indiana

Posts: 490
Any chance it could have been a fairy shrimp, or some other kind of crustacean? It had that kind of movement.
PaulRobertsJuly 25th, 2016, 7:13 pm
Colorado

Posts: 1750
Hi Luke! That's the best guess so far. Long, lean, gliding, and transparent would describe both critters.

The cons are: Supposedly they don't do well with fish predators around and there are plenty of bluegills and bass in this pond. And, fairy shrimp are pretty fast swimmers, I think. The guy I recorded was cruising pretty slow.

Thanks for piping in.
CrepuscularJuly 26th, 2016, 7:13 am
Boiling Springs, PA

Posts: 896
how about a leech? i've seen some pretty light colored ones from time to time.
PaulRobertsJuly 26th, 2016, 10:18 pm
Colorado

Posts: 1750
I don't think so -they undulate. I'm stumped. Not even sure what else to consider. Best guess so far is fairy shrimp.
Jmd123July 27th, 2016, 12:13 am
Oscoda, MI

Posts: 2083
A transparent larval fish of some sort, perhaps a baby lamprey, or other eel-like species? Or a baby bowfin?? I mean we're talking just out of the egg here if that's what it is...??? I see a very slight degree of undulation, but not much, like the swimming leeches I saw today. I go for larval fish of some sort.

Jonathon
No matter how big the one you just caught is, there's always a bigger one out there somewhere...
PaulRobertsJuly 27th, 2016, 9:47 pm
Colorado

Posts: 1750
I'd considered that Jonathon. I looked at larval gizzard shad and carp (this is a warmwater pond), but I didn't see a fit. Some saltwater fish have leptocephalus larvae that free drift before undergoing metamorphosis. Shad have fairly "underdeveloped" larvae, but they didn't fit.

Unfortunate that the image is so poor.
MartinlfJuly 29th, 2016, 7:46 am
Moderator
Palmyra PA

Posts: 2691
Another mystery. It amazes me that for all we humans know, we still run into things that we can't explain. Oh, I assume somebody would know what this creature is, but it doesn't seem to be very easy to identify for some pretty knowledgeable folks. Love it. Thanks, Paul.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
PaulRobertsJuly 29th, 2016, 10:14 am
Colorado

Posts: 1750
Thanks, Louis. A bit off-topic for a trout focused site, but I was stumped. My best stab was a Gastrotrich, so I contacted a world authority. He didn't know what it was, only to say it wasn't a Gastrotrich. I have no more guesses so I thought I'd shoot it out here where reside people who are interested and willing to delve into cool things, even those tiny and complex. Thanks for trying all. It will remain labelled "strange critter".
EntomanJuly 29th, 2016, 1:08 pm
Site Editor
Northern CA & ID

Posts: 2604
Hi Paul,

Were there a a lot of tails or just a few? Were mandibles noticeable or not? Were there any noticeable legs or other appendages? If it weren't for the size I would have thought phantom midge larvae, but it still may be dipteran of some kind...
"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
PaulRobertsJuly 30th, 2016, 7:18 pm
Colorado

Posts: 1750
Hi Kurt,

I have no anatomical details to offer, only the video posted. I know it's not much to go on.

Phantom midge is a good guess: transparent, elongate, open water. But the vids I watched of them show them with a twisting swimming motion, like mosquito larvae.
PaulRobertsAugust 11th, 2016, 11:50 pm
Colorado

Posts: 1750
Chaetogaster?
http://www.micrographia.com/specbiol/helmint/annelhom/olig0100/stylar00.htm
Ceratopogonidae?
https://www.youtube.com/watch?v=6kGNwFsw7zc

I'm still guessing.

Quick Reply

You have to be logged in to post on the forum. It's this easy:
Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.

Related Discussions

TitleRepliesLast Reply
Re: Life cycles and hatches
In the True Fly Family Chironomidae by Leahdanger
3Mar 9, 2014
by Entoman
Re: Little guessing game: Most-used words on this forum?
In General Discussion by Troutnut
14Apr 18, 2011
by Troutnut
Re: please help.what larvae is this
In the Identify This! Board by Alvin
2Apr 7, 2012
by Crepuscular
Re: another caddis question
In General Discussion by Goose
12Oct 21, 2006
by GONZO
Identification: Limnephilidae
In Limnephilidae Caddisfly Larva by Litobrancha
0
Re: northern california caddisfly
In the Identify This! Board by Troutnabout
11Oct 18, 2012
by Entoman
Re: The Run at Boiling Springs
In General Discussion by SteelyKrazy
2Jan 30, 2010
by SteelyKrazy
Re: Site updates from May 28, 2011
In Site Updates by Troutnut
4Jun 2, 2011
by PaulRoberts
Re: Grass shrimp
In Fly Tying by FredH
6Nov 26, 2012
by FredH
Re: Nymph size Question
In General Discussion by DrLaser
4Jun 8, 2012
by Wiflyfisher
Most Recent Posts
Re: euro nymphing leader question
In Gear Talk by Dale1386 (Iasgair replied)
Re: Grannoms and Blue Quills
In Fishing Reports by Martinlf (Roguerat replied)
Survey for swiss fly fishing reel maker
In Gear Talk by Swisssagar
Re: Lost my Brodin net - Ugh!
In General Discussion by Wbranch
Re: New too fly fishing, have some questions.
In General Discussion by Trailman (Troutnut replied)
Re: How to find out what to fish for nearby?
In Beginner Help by Thethrill02 (Trailman replied)
Re: Steelhead coloration
In General Discussion by Roguerat (Strmanglr replied)
Re: Trump administration attacks on trout streams
In Site Updates by Troutnut (Adirman replied)
Re: Stock image of the black fly larvae
In Simuliidae Black Fly Larva by Strimble (Troutnut replied)
Re: kreinik braid
In General Discussion by Flytyerinpa (Planettrout replied)