I usually kept the "damba" groups in shoals of at least 6
The lamena group usually killed each other after a while, I believe I probably didn't have enough flow for these rapids dwelling type, in my 150 gallon way too small.
My 150always became too small for menerambo and maculatus, when the menerambo hit over 12", and the maculatus 10". I had better luck when I moved them to a 400 gal kiddy pool.
Kieneri were the only ones that did well in a tank as small as 150 gallons.
kieneri above, maculatus below
lamena spawning above, menerambo below