Fish That Can Change Their Gender
Blue-banded goby The blue-banded goby is considered a bidirectional hermaphrodite because it can quickly change its sex more than once. Essentially, a male can transition into a female when the need arises.
Chinook salmon Sex reversal in this species is quite unusual, and it appears to be a result of environmental estrogens from ecologically harmful sources (e.g. industrial runoff, pesticides). Another possible reason for mass feminization in salmon populations is unstable water temperature.
Clark’s anemonefish Also known as the yellowtail clownfish, Clark’s anemonefish is a small-sized marine species that favors the warm waters of tropical reefs and lagoons. As suggested by its common name, it has a symbiotic relationship with a handful of host anemones. While it protects the anemone from parasites and predators, the anemone provides it with cover and food scraps.
Black sea bass The stimuli that trigger anatomical changes in black sea bass are not yet fully understood, but biologists have proposed that it simply is a response to the loss of males. As the largest and most physically fit females undergo the transition, their genes have more chances of being passed down to subsequent generations.
Ambon damselfish A protogynous hermaphrodite, the Ambon damselfish starts off as female. Over time, as females become part of sexually mature groups, the largest ones undergo a sex change to take the place of males.
Asian sheepshead wrasse Also known as ‘Kobudai’, the Asian sheepshead wrasse is an enormous marine fish that can weigh as much as 32 pounds (14.5 kg). Its current popularity is largely due to the attention it gained as a sex-changing fish in BBC Earth’s Blue Planet II.
Australian barramundi Unlike many reef species that start off as female fish, the Australian barramundi initially matures into a male specimen. It retains its sex for at least one spawning period, after which the largest individuals may begin to transition into females.
Potter’s angelfish Commonly found in Hawaii’s coastline, this angelfish is a protogynous hermaphrodite. In the absence or decline of dominant males, the largest female may begin to transition. Its social group, usually referred to as a harem, consists of an alpha male and several females. The male pairs up with one of the females during the spawning period, which occurs sometime from December to May.
Ribbon eel Depending on their life stage and sex, ribbon eels display one of three color patterns. Juveniles that have yet to undergo sexual differentiation are usually jet black, save for a fine streak of yellow along their dorsal fin.
Blackhead seabream The blackhead seabream is a commercially important fish throughout its native range due to its valuable meat and appeal as a sport fish. To meet demand for the high-quality proteins of this marine species, it is occasionally farmed in Japan.