Following on from last week’s post about sex change in fishes, this week’s is about a fish that can change in both directions!
The blue-banded goby (Lythrypnus dalli) lives in a harem of one male with 4-6 females. The male is socially dominant and the females live as subordinates. However, if the male is removed, the highest ranking female assumes a poison of dominance. She begins to display male-typical social and sexual behaviours. Within a few weeks, her gonads, accessory sex glands, brain chemistry, endocrine profiles and growth rate become male. Interestingly, when a more dominant male is introduced into this mix, the newly transformed male will revert back to female.
