In this case, color intensity is probably not an indication of sex. A harassed fish is likely to show muted colors and will look pale regardless of sex. Incidentally, how long are these guys? I usually wait until I find kribs at a larger size when they are easily sexed and when I can just buy a pair from the get go. Even though kribs are easily sexed, they still need to be a reasonable size. These guys look fairly small, but it's hard to tell how large they are without something for perspective.
+1. My guess from what I see and know is that you have two females. The aggressive one is brighter because it's the dominant fish, the harassed fish is paler because it's constantly stressed. The difference in color intensity has nothing to do with sex. And, as fishorama pointed out, males typically have spots on the top half of the tail fin.
IME, kribs are as easy to pair up as convicts. It's usually just a matter of putting a male and a female in the same tank. And established pairs are usually mellow toward each other. If you had a pair I think they probably would already be looking for a place to spawn, even if they are too immature to actually do so yet.
Yep, WYite, the more colorful female looks ready to breed or close to it. The very pink fat tummy says it all to me.
Muldoon, maybe you can trade the "lesser" female for a more likely male (spots on tail!!)...But a ready female will not have much patience with a too young male that doesn't know what to do yet...You may need to offer many hiding places until he's ready too, or get an older male. Kribs are very easy to breed...maybe too easy...but fun!
Part of the problem is females are smaller & mature earlier than males...kind of like people, lol...Now you know what to look for, if you want to breed them. You still haven't said your tank size but in many ways that can matter.
I’ve been thinking about getting a female krib for my 125l tank since females tend to get smaller 7.5cm ish. My water hardness is over all 253ppm, around 14-15 dGH. I have several cherry shrimps, young and adults, adult amano shrimps and 1 2” gabon shrimp, livebearers, mts snails and a pleco. I worry about the female krib attacking the shrimp as i have small cherry shrimps, but the amano shrimps are larger ofc. I could put the shrimp in with my betta if something goes wrong or not.
I’ve never kept freshwater shrimp but I did have a 36 tall a few years ago with some guppies and a female kribensis as well as a keyhole and some small plecos(forget the type) and everything worked out. The two cichlids mostly stayed near the bottom and guppies hung out around the floating plants. Hope that helps