These Fish Swap Their Sex Up to 20 Times a Day
The hermaphroditic chalk bass, a Caribbean native, switches from female to male and back again, multiple times a day.
The natural world offers many curiosities, but hermaphroditism—the presence of both male and female reproductive organs—may be among the most peculiar.
Take the chalk bass (Serranus tortugarum), for instance. New research published in Behavioral Ecology suggests that the small reef fish, no more than three inches long, may switch sex roles with their partner up to 20 times each day.
Chalk bass use a reproductive strategy known as “egg trading,” wherein they subdivide their daily egg clutch into “parcels” and alternate sex roles with their mating partner throughout a sequence of spawning bouts.
The fish demonstrated a remarkable commitment to varying their sex roles, explained Mary Hart, an evolutionary ecologist at the University of Florida and the lead author on