7/2/25
“Some of these sex changers can flip with astonishing frequency. The chalk bass (Serranus torugarum), a neon-blue Caribbean fish that’s about the size of your thumb, has been known to switch sex up to twenty times a day. Chalk bass don’t do this in order to play the field; quite the opposite - switching sex is their recipe for relationship success. Chalk bass are known to display unusual levels of sexual fidelity and are considered more or less monogamous. Their sex change habits are a coordinated response with their long-term partner. Researchers believe that taking turns laying eggs, which are bigger and more energy-consuming to produce than sperm, keeps the reproductive investment fair. Each fish fertilizes as many eggs as it produces. Proving that even with fish you get what you give in a relationship.”