#protogyny

Princess parrotfish (Scarus taeniopterus) terminal phase male off the coast of Cozumel in Mexico

A lot of people through history and the modern day have an overly simplistic view about sex, both in the sense of biological sex (that is, what gametes something produces) and sex as in the act of mating. A lot of people think that sex is just a strict binary between males and females, but nature is far more diverse and varied than that (even in humans. Intersex people do exist after all). Today I'm showcasing one of the animals that completely goes against the alleged sex binary: the California Sheephead Wrasse. And yes, this is a pride post.

(Image: a male California Sheephead Wrasse in a tank in the Monterey Bay Aquarium. It is a large fish with a bulbous head. The head and tail are black, midsection is pink, and the belly and chin are white. End ID)

The California Sheephead (Semicossyphus pulcher) is a large fish in the Wrasse family of Labridae. They are sexually dimorphic, with the males and females appearing distinct from each other in size, shape, and color. Males are larger than females, reaching up to 91 cm (3 ft) and 16 kg (35 lbs), though there is quite a bit of size variation based on food availability. They have flatter faces than females thanks to a bulbous bump on the forehead. This lump is the namesake of the fish, since it allegedly make it look like it has a sheep's head. I personally don't see it at all. Males have black heads and tails with a white chin and underbelly and pink midsection Females are smaller and colored silvery to a dull pink all over except for their white chins and underbellies. There isn't really a maximum size or weight for females for reasons I'll get into later. The fish have large canine teeth that protrude from the mouth and modified throat bones that form a grinding apparatus called the throat plate.

(Image: a female California Sheephead. It has a less bulbous head than the male and is a pale pink all over, except for the white belly and chin. End ID)

Sheepheads, like many wrasses, are sequential hermaphrodites. A sequential hermaphrodite can transition between sexes during its life (as opposed to a simultaneous hermaphrodite, who can produce both sperm and eggs at the same time). Every California Sheephead is born female and some will become male later in life, making them protogynous. Protogyny is the most common form of hermaphroditism in fish, with over 75% of known sequentially hermaphroditic fish species being protogynous. This transition is a one-way process, males will not turn back into females. The transition is triggered by a number of factors, primarily size and the local availability of males. If there are not enough males in the area, the largest female will transition to male to fill the role. This transition takes between 2 weeks and a few months depending on availability of food and other conditions (temperature seems to play a role) and the fish will be capable of producing sperm before fully assuming the male morphology.

(Image a male and female Sheephead swimming next to each other. The female is roughly half the size of the male. End ID)

During mating season (July-September), males will pick a territory and claim all nearby females as mates. A younger male without a territory may challenge an alpha male to try to claim his territory. These fights are often resolved with threat posturing, but if neither male backs down, they will fight with biting and raking teeth against the opponent. During mating season, females will release batches of 375,000 eggs almost daily for males to fertilize. During this time, the alpha male will patrol his territory to mate as much as possible while chasing off smaller males who may attempt to sneakily fertilize some of his female's eggs. The larvae are planktonic for their first 34-78 days, and will sink as they grow. Juveniles have a different coloration to the adults. They are orange, with a white stripe running down the body and dark spots on the fins. The average maximum age of a California Sheephead is 21 years, but the oldest individual on record was 53 at the time of capture.

(Image: a juvenile Sheephead. It is a small, orange fish with a white stripe running from eye to tail and black spots on the pelvic, anal, dorsal, and tail fins. End ID)

The California Sheephead lives on rocky reefs and kelp forests from southern California to the Baja peninsula and Gulf of California. They prefer shallow water between 3 and 30 meters (10 - 100 ft) deep, though males will occasionally venture deeper. Sheepheads are predators that hunt hard-bodies invertebrates including urchins, shelled molluscs, and crabs. Juveniles hunt smaller prey such as sponges, bryozoans, and barnacles. The protruding canines give the fish a better grip when trying to pry food off of rocks. They crush the hard shells of the prey with sharp teeth before swallowing. The shells are then further ground down by the throat plates. Smaller individuals have been known to break open urchins too large to bit by picking them up and hammering them into rocks. Sheepheads play an important role in kelp forest ecosystems by keeping urchin populations down. Urchins eat kelp and without predators keeping their numbers in check, can reduce kelp forests to urchin barrens. Sheepheads are known to have a high site fidelity, meaning they will return to the same places over and over. They will maintains a sleeping spot (usually a crevice they can hide in or rock they can hide under) and return to the same places to hunt. They are diurnal and return to their sleeping spots at night to avoid predators.

(Image: a male Sheephead trying to pick up a sea urchin with tis mouth. End ID)

California Sheephead Wrasses are classified as vulnerable to extinction by the IUCN. Their primary threat is overfishing. The Sheepheads have been commercially fished since the 1800s and their numbers have dropped. The hermaphroditic nature of the species actually makes things worse. Commercial fishers are incentivized to catch the largest fish and the largest Sheepheads are the males and females that are likely to transition to male. Unlike with other species, there aren't small males around to make up for the loss of large males to fishing since the small fish are the females. The loss of males and the largest females (who are the ones most likely to transition to male) means there aren't enough males around during mating season to keep the population high enough. The introduction of marine protected areas and fishing regulations have helped the population recover. The loss of the Sheepheads is a big deal since they're one of the species doing the most to keep the kelp forests healthy by eating urchins. Natural predators of the Sheepheads include sharks, sea lions, and giant sea bass.

@allhailthequeenuwu 's alien/Bleghrian oc with male Bleghrian and variants.

Rainbow parrotfish (Scarus guacamaia) terminal phase male off the coast of Cozumel in Mexico

Slippery dick (Halichoeres bivittatus) initial phase females at Akumal in Mexico

Tri-color parrotfish (Scarus tricolor) terminal phase male at Réunion Island in France

Sunset wrasse (Thalassoma lutescens) terminal phase male off the coast of Tahiti in French Polynesia

Stoplight parrotfish (Sparisoma viride) initial phase female off the coast of Miami, Florida in the U.S.