Loaches Online Forum

New to the forum. Hello loach lovers etc.Currently have a hillstream loach tank correctly set up with 3 gastromyzon and 6 kweichowsis(sorry, can't remember the spelling), few mountain minnows and a true flying fox. My gastromyzon as you'd expect an stick to their favourite rocks like glue and lose their colour over night but they have only recently begun to engage in a type of battle that combines both and i was wondering if any could explain it....
It only happens over one specific rock right by the filter outlet although always with different loaches (never the gastromyzon) but only two at a time, they'll spend a good 5 minutes, sometimes much longer, going head to head over this particular rock, theres no jumping as may be expected but interestingly durig the fight their colouration completely saps away, i doubt this is through fear as even the shyest of my loaches, who would swim off anywhere else. will stay. One loach will try and get behind the other and lift its tail off the rock with his nose and this will go on and on, colour waning until eventually they give up and swim off to recuperate. Am i reading too much into this or could this (please,please,please) possibly be mating behaviour?
I am 100% certain its not your average loach territorial dispute.
Any advice would be greatly appreciated, or hope-dashing for matter....
Fingers crossed

Welcome to Loaches Online!
Sorry, but that sounds like typical hillstream territoral disputes to me.

I would add more rocks, and a strategically placed powerhead so the rocks get a lot of water movement.

Hmm...
The 20 gall tank (my minnows are there temporarily) is highly filtered, external canister for a 40 gal and internal canister for a 30gal but its the one rock sheltered from water movement. It was setup after a fair bit of research, specifically aimed at hillstream loaches.
I suppose you guys are the experts, yet still does it often happen that loaches lose colour as they battle?
Firstly; Theres endless minor disputes in the tank but colour loss (in my tank at least) only takes place under the aforementioned circumstances.. Or at night. I mean strong colourloss from typical dark green to beigey yellow.
Secondly; Its the pushing of the nose under the tail that made me think of breeding, all other disputes involve either jumping on top of the opponent (at least attempting to) or side to side/nose to nose "sumo" battles. Its a constant chase one behind the other, one will freeze and the other poke his nose under. I know hillstreams are rarely bred in captivity, is there anywhere i could get some info on typical breeding behaviour or has it not been observed in detail yet?
Thanks anyway, i'm probably being a bit stubborn as i'd love to think that breeding is a possibility.

2 of our yo-yo's exhibit the same behavior and I also wondered if it could be characteristic of breeding behavior.

It seems some territorial disputes get more nasty than others and thus the color loss in some and not the others.
As far as breeding behavior goes, it has been observed numerous times by several people who post on this board. You can check the articles section (Hillstream articles) on this site and see Emmas' article on Sewellia breeding and Martin's on Pseudogastromyzon cheni breeding activity .
You can also check out the species profile for Liniparhomaloptera disparis disparis and read about breeding activity in the notes section.
Keep observing this behavior, however. We can only hope it leads to breeding.