purpose of bright colors on fins of fish ( red tailed hillstream loaches )

[Magnum Man35 149]

So, I would suspect that bright colors are predominantly used in mating for most fish… however hillstream loaches rarely flair out their tail fins, by design ( because of their environment ) I have a handfull of the red tailed loaches, and a couple of blue tails…both are very pretty fish, when they are displaying… these varieties have proven hardy, and are easily kept, but I can rarely tell that they have any color in their tails, except for that occasional flash of color, I get to see infrequently… ( so almost never in a picture ) I see a flash once in a while, when they make an adjustment in the tank, or stretch, but it doesn’t seem to be related to interaction with others…

here are a few on line pictures of these fish, someone was lucky, or skillful enough to capture, and I get to witness as an occasional flash of color, in my tank…

 

[GaryE]

Display has a huge cost. Fish that keep the lights on all the time get eaten. So a little bar of colour like that may be a compromise - working to show the male is a fine looking fellow, but not attracting predators.

There's been a lot of work done on understanding how sexual selection works in fish. We aren't in the old days when male researchers started out convinced males did the choosing, with harems and all kinds of fantasies woven into their analysis of fish. With most species, the female does the deciding and the male has to have something to show his attractiveness. A splash of colour like that must be enough for those loaches. My female killies would not be impressed.

 

[Innesfan32 16]

There's a study well-known by serious guppy breeders that female guppies prefer and select males with orange patches on their bodies and fins. Also that populations of guppies in locations with few to no predators are more colorful than those with predators present.

 

[GaryE]

Colourful males also stay in places where they can be seen by females, who stay in cover and live much longer. When you unpack colourful wild caught killies, you can sometimes get 95% males, as they are so much easier to catch when they're showing off. This is even though overcrowded males will sometimes knock each other off in the drums they hold them in prior to export.

All the human males on this forum are, frankly, sizzling hot specimens, but we don't have to worry about kingfishers.

 

[Back in the fold1]

All the human males on this forum are, frankly, sizzling hot specimens, but we don't have to worry about kingfishers.

Thank you . I’ve always suspected that but the confirmation is appreciated .