MyFishFinder Forum
My Fish Finder Main => General Fishing Discussion => Topic started by: taxid on Jun 02, 2019, 11:13 AM
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Allegedly a brown trout male and possibly rainbows as small as 4 inches have an anal fin that is convex as in like this ) on the outside edge. And allegedly a female brown has an anal fin that is concave, and more or less like this on the outside edge of the anal fin ( (See photo below).
(https://i.imgur.com/8nPSnpS.jpg)
https://www.ginkandgasoline.com/fly-fishing/2-ways-to-determine-the-sex-of-a-trout/
Prefer to see fish that are obvious males and females to verify the anal fin differences.
So far all pictures I've seen seem to verify the above.
And yes I know a mature brown trout or rainbow trout is easy to tell from a female due to the kype and coloration during spawning, but immature and small fish may not be so easy.
Here's one source that alleges this and I have a article form a biologist in McClane's Fishing Encyclopedia that says the same under the heading of Brown trout.
As a fish culturist, if this is really true, it would help me out a lot as I can sort the males from the females early on to save on feed costs and increase the number of males in the pond. My taxidermy and replica market is primarily male fish.
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Interesting..never heard that one. I'll try and get some pics, we are going to be sorting browns soon for summer spawn.
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Thanks! I thinned mine out but can't get them to set still long enough to get a look at their little fins. Browns are in the 5 inch range and rainbows in the 6 inch range. I have some MS-222 but afraid to overdo it and kill them.
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This what you are looking for?
(https://i.postimg.cc/jDDpT6g2/imagejpeg-1-2.jpg) (https://postimg.cc/jDDpT6g2)
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This what you are looking for?
(https://i.postimg.cc/jDDpT6g2/imagejpeg-1-2.jpg) (https://postimg.cc/jDDpT6g2)
Yes!
Is that a male or female in your opinion? It appears to be a female to me, which would make her an exception to the rule as her anal fin looks convex.
Do you agree? I don't see a kype.
OTOH upon closer examination the anal fin seems convex toward the bottom rear edge but concave at the top of the rear edge? Maybe swings both ways? :rotflol:
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Hope this 1 is visible
(https://i.postimg.cc/R64mcn0Q/FDD4-DDAE-FD5-C-4490-A724-AF7-A136-A3358.jpg) (https://postimg.cc/R64mcn0Q)
Thanks for the picture but your hand is over the anal fin. :rotflol:
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Thanks! I thinned mine out but can't get them to set still long enough to get a look at their little fins. Browns are in the 5 inch range and rainbows in the 6 inch range. I have some MS-222 but afraid to overdo it and kill them.
Have you tried clove oil for knocking them out? They don't seem to get too sleepy. It think the mix is 1 part clove oil to 8 parts ethanol, but I think we've used straight clove oil before.
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I have used clove oil to euthanize them for harvest to the taxidermy market but prefer the MS222. Seems to take a lot to work for me with my water chemistry.
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Beats me Cecil?! I can tell you when I stuck that pig...we went for a ride!
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How’s about this one. Looks to be a male to me:
(https://i.postimg.cc/dD2HCjqg/F9696071-7-B7-E-449-A-9979-A35192-B1-B28-D.jpg) (https://postimg.cc/dD2HCjqg)
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Beats me Cecil?! I can tell you when I stuck that pig...we went for a ride!
:rotflol:
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This was a female for sure
(https://i.postimg.cc/wtvrnS6r/42559-AA3-E871-47-B5-AFC2-8308-CBFA00-EB.jpg) (https://postimg.cc/wtvrnS6r)
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How’s about this one. Looks to be a male to me:
(https://i.postimg.cc/dD2HCjqg/F9696071-7-B7-E-449-A-9979-A35192-B1-B28-D.jpg) (https://postimg.cc/dD2HCjqg)
Definitely a male with that kype going. Fin looks neither concave or convex to me. What do you think?
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This was a female for sure
(https://i.postimg.cc/wtvrnS6r/42559-AA3-E871-47-B5-AFC2-8308-CBFA00-EB.jpg) (https://postimg.cc/wtvrnS6r)
Yep. Fin does look concave like it's supposed to.
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I think you have us on a goose chase Cecil!
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What geese? ;D
No I'm seriously pursuing this.
Did find a Canadian reasearch paper online that discusses it but they want me to pay a fee to access it. I will probably pay the fee when I get back from vaca.
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I think if it was as easy as sexing livebearers, like little guppies and mollies, it would be more published information. With some fish like cichlids you can tell males by how the dorsal and anal fins taper out more vs females being rounded and shorter.
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I think if it was as easy as sexing livebearers, like little guppies and mollies, it would be more published information. With some fish like cichlids you can tell males by how the dorsal and anal fins taper out more vs females being rounded and shorter.
That may be true but I've been told by state and federal hatchery managers recently after sending out some queries that there is no incentive to even know the sexes until they are sexually mature for spawning purposes. By then it obvious and there is no need to look at the anal fins.
Two of them have said it may or may not be true but they've never checked or had a reason to on sexually immature fish.
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I guess from a hatchery stance that makes sense, but not if you’re really tying to know everything you can about the species as a biologist. Granted it’s not like there are thousands or millions of people watching these fish in their tanks at home do their thing.
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That may be true but I've been told by state and federal hatchery managers recently after sending out some queries that there is no incentive to even know the sexes until they are sexually mature for spawning purposes. By then it obvious and there is no need to look at the anal fins.
Two of them have said it may or may not be true but they've never checked or had a reason to on sexually immature fish.
This is really got me interested. We actually are looking at selecting fish before spawn. For instance we have a strain of steelhead that at sexual maturity( age three and age four) some are bright and shiny and not ripe at all. I actually held fish another year, just to see if they ripened...they are still shiny at age four. It appears that they are all "females", saying this because generally in our populations when they mature there is a 50/50 mix of boys to girls. The shiny steelhead percentage of around 17% added to the ripe females was roughly 50% of the population. If we can pick out this shiny component early on we can save on feed and space. Usually by age two the boys can be sexed.
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Really doubt that holds true for all brown &/or rainbow trout.
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Really doubt that holds true for all brown &/or rainbow trout.
You may be right. I tried sexing yellow perch when they were not spawning by the appearance of their urogenital openings. Even that is only 90 percent.
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This is really got me interested. We actually are looking at selecting fish before spawn. For instance we have a strain of steelhead that at sexual maturity( age three and age four) some are bright and shiny and not ripe at all. I actually held fish another year, just to see if they ripened...they are still shiny at age four. It appears that they are all "females", saying this because generally in our populations when they mature there is a 50/50 mix of boys to girls. The shiny steelhead percentage of around 17% added to the ripe females was roughly 50% of the population. If we can pick out this shiny component early on we can save on feed and space. Usually by age two the boys can be sexed.
The female tiger trout I have are like that. Stay pretty much silvery. And I can't sell them worth a darn as the taxidermists only want the brightly colored males with distinct markings.
BTW tried sexing smallmouth bass with X-rays. Only thing that stood out were the bones and the air bladder. Egg sacs did not show up in the X-rays. Ultrasound was even worse.