That's a really useful insight - and one I have not encountered before, although admittedly most of what I think I know has been gleaned on-line or through personal observation. But it does put it beyond any doubt.If all three are sparring, they're males. Females don't spar. And that photo is great.
Don’t worry if your fish look different when you switch on the aquarium lights after dark or in the morning as like most Nannostomus species it assumes a paler, cryptic colour pattern at night, in this case the dark lateral stripes disappear and two oblique bars are visible posterior to the dorsal-fin.
This diurnal rhythm has been show to occur in blind specimens, suggesting it’s an automatic response that the fish cannot control.
Ha ha. Today she was responsible for an additional 10 litres in the weekly w/c.That crater is getting deeper
Arghhh - I've already trimmed the roots twice in the last 7 days
View attachment 368495