The bump is called a nuchal hump (you may see flowerhorn keepers calling them koks). It contains water and fat, and can be inflated or deflated depending on the fish's nutritional and SOCIAL status! Usually dominant males have the largest. Females and subordinate males may show it a little as well if they are well fed.![]()
Oh sounds like a camels hump sorta! So it's a sign of dominance and good health?
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