Has it? It's not an illness or disease, lol.
T.espei is just a different species that sometimes gets mixed up or mixed in with harlequins
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But they're slightly smaller, more copper coloured, and the black "lambchop" is more narrow. But looking at the new photo, you're right, they do all look like normal harlequins
In that first pic you had, the one at the front did look a bit espei like to me, so thought you might find it interesting to check!
It's nice that you have a purple one mixed in too, I'm not a big harlequin fan, but I kinda want some of the purple ones now!