https://www.nytimes.com/2022/10/14/science/sarcastic-fringehead-mouth-display.html Sections SEARCH Skip to contentSkip to site index Science Log in Today's Paper Science|When Sarcastic Fringeheads Open Their Mouths, Watch Out https://www.nytimes.com/2022/10/14/science/ sarcastic-fringehead-mouth-display.html * Give this articleGive this articleGive this article * * Advertisement Continue reading the main story Supported by Continue reading the main story Trilobites When Sarcastic Fringeheads Open Their Mouths, Watch Out Scientists found that the fish's unusual broad-mouthed display is reserved only for fighting with other members of its species. * Send any friend a story As a subscriber, you have 10 gift articles to give each month. Anyone can read what you share. Give this articleGive this articleGive this article * * Video Cinemagraph Sarcastic fringeheads are not sarcastic about fighting for who gets to live in this shell. Video by Watcharapong Hongjamrassilp. By Jason P. Dinh Oct. 14, 2022 Let's start with the name: The fish is really known as the "sarcastic fringehead." "Fringehead" refers to the frills lining its forehead. And Watcharapong Hongjamrassilp, a biologist at Chulalongkorn University in Bangkok who studies the fish, said scientists called it sarcastic not because of its withering sense of humor, but for its propensity to lash out at anything threatening its nest -- even humans. They may have been referring to an ancient Greek word that means "stripping off flesh." Once you get past its name, the fish's behavior is fascinating. Watch sarcastic fringeheads long enough and you'll see them parachute their mouths outward like a lion's mane. The display exposes a curtain of flesh that beams with yellow outlines, indigo tie dye and an ultraviolet glow, as if it were a dangerous Demogorgon from Netflix's "Stranger Things" dressed for an EDM festival. Naturalists and filmmakers have documented the remarkable behavior during fights between fringeheads before. "But we had no scientific support that this behavior is used just for fighting and not for courtship or some other purpose," Dr. Hongjamrassilp said. Dr. Hongjamrassilp and his colleagues discovered that sarcastic fringeheads performed their outlandish displays not to attract mates or to fight other species but rather to fend off their own kind, potentially when competing for scarce resources. "It's great natural history, and they also use this observation to get at evolutionary mechanisms," said Yusan Yang, an evolutionary biologist at Washington University in St. Louis who was not involved with the study that was published last week in the journal Ecology. ImageA sarcastic fringehead, with its jaws open and its flesh flaps stretched out wide and colored in fluorescent pinik and yellow, lunges from a shell at another fringehead, whose jaws are also extended, on a bed of sand in a tank. The sarcastic fringeheads were retrieved from the wild in waters off the coast of Southern California, where they were found living in snail shells, rock crevices and human litter like snorkel tubes and glass bottles.Credit...Watcharapong Hongjamrassilp The team observed male sarcastic fringeheads in the wild by scuba diving off the coast of Southern California. As one of the largest species in their family, these fish can grow to be as large as a foot long. The divers found them living inside coconut-size snail shells, rock crevices and even in litter such as snorkel tubes and glass bottles, Dr. Hongjamrassilp said. The team members observed fights and courtship occurring just outside fringehead living quarters. They also documented quarrels between the fish and other species like octopuses or even scuba-diving scientists. When female sarcastic fringeheads came calling, the bachelors would emerge and jerk their heads from side to side, but neither partner displayed parachuting mouths. Similarly, when another species approached, the fish would charge and nip the intruder, but they never flared their faces. The fish only flaunted their vibrant cheeks during competition with their own kind. To test how the display functioned during fish fights, the team captured 15 male sarcastic fringeheads and took them back to the lab, where they staged competitions over a vacant snail shell. Usually, the bigger fish with longer jaws won. What's more, the mouthy display seemed to prevent contests from escalating to dangerous brawls. The sequence of behaviors was consistent across the fight card. When two fish crossed paths, the resident usually displayed first. The intruder would then reciprocate or retreat if it was much smaller than the signaler. If things still weren't settled, they would ram their faces into each other, mouths agape, almost like an awkward adolescent kiss. Image Dr. Hongjamrassilp said the jaw's yellow outline might emphasize a fish's size, and its mennacing display reveals its jagged teeth and muscles.Credit...Oriana Poindexter And if things didn't end there. ... Well, that's when it got ugly. One fish would sink its teeth into the other, threatening to gouge its eyes or uproot its eyebrow-like fringes. Dr. Hongjamrassilp hypothesizes that the display communicates the signaler's size or strength. The yellow outline could advertise how big a fish is, and the prominent muscles that are visible inside the mouth could signal the strength of its bite. Once an individual displays, though, it's probably blindfolded by the expansive drape of flesh. That means fighters have to assess each other before the jaw-jousting begins. "The funniest thing is they probably don't even know who they are fighting," Dr. Hongjamrassilp said. This study is just the first step to understanding why the dramatic behavior evolved in sarcastic fringeheads but not in its close relatives. Dr. Hongjamrassilp suspects that it has to do with their large body size and fierce competition for cavernous shells that can accommodate them, but without data from other species, it's impossible to know. "Obviously, there are a lot of unknowns in the system," Dr. Yang said. "But as a first step, this is pretty awesome." The future of fringehead research might not include Dr. Hongjamrassilp, though. He was recently diagnosed with glaucoma, and his physician recommended he give up scuba diving. "Luckily, I already collected data to answer the question about evolution," he said. But after that swan song, his colleagues and co-authors will have to pick up where he leaves off. / Advertisement Continue reading the main story Site Information Navigation * (c) 2022 The New York Times Company * NYTCo * Contact Us * Accessibility * Work with us * Advertise * T Brand Studio * Your Ad Choices * Privacy Policy * Terms of Service * Terms of Sale * Site Map * Canada * International * Help * Subscriptions