hi i saw a post about the fish playing with the human child and even though your addition to that post is 3 years old by now i would love to hear more about ftm sheephead fish :3 (no pressure btw!)
Fish curiosity, in my inbox?? It's more likely than I think, apparently! xD
First off, there's actually multiple fish dubbed 'sheephead'! There's the sheepshead- note the extra S in there- and they look like this:
And yes those are their teeth. Horrifying tbh, but they're very good at what they do- crushing invertebrates and other shelled snacks! They're an Atlantic species that sticks to temperate and warmer waters, and they max out at about half a meter in length.
That's not the fish we're talking about today. The focus of today is the California sheephead wrasse- note the lack of a second S- also known as the 'sheephead' for short. Not confusing at all! We definitely don't bash our heads into walls over the naming conventions and lack of record-keeping of our scientist predecessors.
THIS is the sheephead wrasse, the species of the lovely and now Tumblr-famous Red! :D With a length of up to a FULL meter, they're a whole different size class of fish! They can be found along the west coast USA from the Baja Peninsula all the way up to Monterey, and dwell almost exclusively in kelp forests and nearby environments. I will use one of Red's pics as an example of female coloration-
The lighting isn't great but you can see how her body is streamlined, and besides the white underside of the jaw, has a salmon-pink coloration! Females can be pink or a dull silver-beige. And much like other large marine wrasse, MALES have a drastically different appearance.
This thing is built like a damn tank!! Sheephead are a species of wrasse that shift colors to gain those striking black scales and physically bulk up when becoming males- because guess what? ALL OF THEM ARE BORN FEMALE! By default, all male California Sheephead are FTM trans :) They use that bulky head and extremely tough set of jaws to not only hunt their preferred prey- mollusks, gastropods, and bivalves, etc- but also to bash and chomp down on rival males. This one has won many battles, look at that scarred up muzzle!
The sex change is determined by several factors, as it's not guaranteed all sheephead will eventually become males. Because sheephead school in a harem system- many females to very few males- in order to maximize pressure of stronger offspring, the biggest and healthiest sheephead male will drive out competition from the school. Naturally, a sheephead that lives longer and gains a greater size will have a much higher chance of shifting from a female to a male, if the conditions are right. Stress induced from competition can suppress the hormones that stimulate this transition in females, so they're less likely to gain size and shift from female to male if there's already strong competition taking place. However, in the event there are too few males to mate with the females, or no males present at all, the biggest female will start transitioning to fill the empty slot! It's a long process that can take as few as a couple months, or up to years, depending on resources available.
Conversely, if there are TOO MANY males, they can revert back into females! This process also takes a long time, and is a lot more rare to witness, especially because right now male California sheephead in particular are being spear-fished into becoming an Endangered species :c Sheephead adult males in good condition are considered a trophy animal in spear-fishing and similar marine trophy hunting off the West coast, and because males in particular are being targeted, the gene pool is being reduced when it wrecks the harem structure of schools.
As a fun fact- they're also an incredibly smart fish, and can form relationships with humans, as demonstrated with me and sweetiepie Red cx There's many documented cases of large marine wrasses forming long-term friendships with divers! Here's a humphead wrasse that made friends with a diver she learned would crack snails open for her with a hammer:
I don't work at the facility with Red anymore, but I currently work with two unnamed adult male sheephead, and once again they both like me and seem to despise all my coworkers, even if I never had the opportunity to train them like I did with little Red xD They pick favorites I guess? Now if only I could make friends with the garibaldi...