Reef predator — with ‘electric blue' lines — found as new species off Mexico
On a remote reef about 90 miles off the coast of the Yucatan Peninsula, a predatory fish scours the shallow seafloor.
Research divers spotted the 3.5-inch-long animals during recent survey trips to the cays of Campeche Bank and used pole spears to reel them in, according to a study published April 4 in the peer-reviewed journal Zootaxa.
The fish belonged to a family called hamlets, a group that has proven difficult to study.
'These fish are interesting for many reasons, one of which is that they are very similar genetically. Different species of hamlet look different (they have different color patterns) and they tend to mate only with members of the same species, yet genetically they are very, very similar,' study author Oscar Puebla told Smithsonian Insider in a 2017 interview about his work.
The fish, originally collected in 2018, looked similar to two known species, as is often the cause for hamlets, researchers said.
But a few key features stood out to the researchers, and a genetic test confirmed their suspicions — it's a species new to science.
Hypoplectrus espinosai, or the Campeche Bank hamlet, can be distinguished from other species by its coloration, according to the study.
'The body color ranges from white to pale grayish-white to pale brownish-white with (about) 15 vertical whitish to pale bluish-white lines that extend from the top of the body profile to near the bottom,' researchers said.
The fish have white faces with a black blotch in front of the eyes, according to the study. The black patch is 'surrounded by electric blue lines that extend onto the forehead, around the eye and onto the lower jaw.'
The back of the fish has a black 'saddle' that is larger than other related species, researchers said.
'We assign the species name espinosai sp. Nov. in honor of Héctor Salvador Espinosa Pérez (1954-2022), a dedicated Mexican ichthyologist, founder of the Mexican Ichthyological Society and curator of the Mexican National Fish Collection,' researchers said. 'The common name refers to the geographic distribution of the species.'
Though the fish is known to be predatory, researchers didn't observe any attack behavior while surveying the new species, according to the study.
'Hamlets are predators that prey on smaller fish and invertebrates. Through aggressive mimicry, the hamlets (the mimics) could have evolved color patterns that look like other herbivorous or omnivorous fish species (the models),' Puebla told the Smithsonian Insider. 'It's the 'wolf in sheep's clothing' trick. It allows hamlets to approach prey without alarm because they look like a harmless herbivore.'
A video depicting a golden hamlet swimming to meet up with its mate was shared by The Royal Society in 2011 to accompany one of Puebla's previous publications.
The new species was identified off the coast of the Yucatan Peninsula in the southwestern Gulf of Mexico. The body of water was renamed as the Gulf of America by executive order on Jan. 20 by President Donald Trump, however this change is not recognized outside the United States.
The research team includes Puebla, Alfonso Aguilar-Perera, Matin Helmkampf, D. Ross Robertson, Carlos J. Estapé, Allison Morgan Estapé and Omar Domínguez-Domínguez.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
20 hours ago
- Yahoo
Glow-in-the-Dark Salamanders May Have Just Unlocked the Future of Regeneration
What if the key to human limb regeneration wasn't buried in sci-fi dreams—but already in your medicine cabinet? Scientists at Northeastern University have uncovered a breakthrough that's raising eyebrows in both the dermatology and regenerative biology worlds. The chemical at the center of it all? Retinoic acid—a form of vitamin A that's also the active ingredient in isotretinoin, better known as Accutane. In a new study, which was published in Nature Communications, researchers mapped how axolotls. The Mexican salamander has a freakish ability to regrow limbs using varying concentrations of retinoic acid to guide the regrowth of bones, joints, muscles and skin. When an axolotl loses a leg, it doesn't just grow back—it grows back perfectly. And scientists now understand more clearly how that biological GPS works. At the heart of the process is an enzyme called CYP26b1, which breaks down retinoic acid and dictates how much of the chemical floods a given area. Higher levels mean longer bone growth. Lower levels cue the development of feet and digits. The implications are massive: by controlling retinoic acid levels, scientists were able to create glow-in-the-dark salamanders with either perfectly formed limbs or comically misshapen ones. While these findings are still at the basic science stage, researchers believe they've taken a major step toward understanding how to activate dormant genetic mechanisms in humans. Because here's the kicker: the genes involved in limb regeneration already exist in our DNA. We just don't know how to switch them back on—yet. Retinoic acid has long been linked to fetal development, and now it's being eyed as a possible tool to coax adult tissues into reprogramming themselves post-injury. It's not a silver bullet, but it might be part of the recipe. 'We might just need to remind the body what it already knows how to do,' James Monaghan, the study's lead scientist, told Popular Science. If that's true, the path to real human regeneration might be shorter—and stranger—than we ever imagined. Glow-in-the-Dark Salamanders May Have Just Unlocked the Future of Regeneration first appeared on Men's Journal on Jun 10, 2025
Miami Herald
a day ago
- Miami Herald
10-foot-long predator — with toxic flesh — is first-of-its-kind catch off Mexico
Off the coast of Veracruz, Mexico, fishermen attached hunks of bonito fish to a longline and dropped it in the water. The nearly 400-foot line drug through the water until something heavy chomped down on the bait and was reeled to the surface. The fishermen recorded a video of the creature on the end of the line as it approached the boat on the July day in 2024, possibly not realizing the significance of the catch. The hook was caught in the mouth of a bluntnose sixgill shark — the first ever confirmed catch 'for Mexican waters of the Gulf of Mexico and the Caribbean Sea.' The shark was brought to shore to be weighed and measured, according to a study published June 6 in the peer-reviewed journal Acta Ichthyologica et Piscatoria. The nearly 10-foot-long shark has a 'robust body' and a 'large and broad head,' researchers said. The shark's 'big mouth' holds 'six rows of large, serrated comb-shaped teeth on each side of the lower jaw.' The shark has a 'prominent tapetum lucidum,' or reflective layer in the eye, that makes their eyes appear 'fluorescent greenish' while alive. The shark was a sexually mature male, likely at the peak of its size, researchers said. Bluntnose sixgill sharks, or Hexanchus griseus, can be found globally, but in patches of ocean instead of widely distributed, according to the study. The first record of the shark in the Gulf of Mexico was in 1962 when a 14-foot female was caught off the coast of Alabama, according to the study. A 10-foot male bluntnose sixgill shark was caught off the coast of Texas in 1984. This record, however, confirms the species's distribution to the southwest region of the Gulf. 'Local fishermen have reported capturing the species on several occasions, however the specimens were released since the flesh is bland and not well appreciated due to its consistency,' according to the study. 'It also has a large amount of fat which is considered toxic. For this reason, species of the genera Hexanchus and Heptranchias have been dubbed milk sharks by local fishermen.' The shark's flesh has an incredibly high concentration of oil, leading to the meat being considered ichthyosarcotoxic, and not safe to eat, according to the study. This means that when the sharks are caught it is typically incidental and they are not specifically targeted in any commercial operations, researchers said. The sharks are usually found below 300 feet, though juveniles swim closer to coastal areas, according to the study. The shark was caught 12 miles north of the community of Salinas Roca Partida. The Gulf of Mexico was renamed as the Gulf of America by executive order on Jan. 20 by President Donald Trump. This change is not recognized outside the United States. The research team includes Luis Fernando Del Moral-Flores, Sergio Alejandro Lozano-Quiroz, Viridiana R. Escartín-Alpizar, Eduardo García-Mercado and Rolando Hernández-Ortiz.
Yahoo
a day ago
- Yahoo
A chemical in acne medicine can help regenerate limbs
If an axolotl loses a leg, it gets a new one–complete with a functional foot and all four toes. Over just a few weeks or months, bone, muscle, skin, and nerves grow back in exactly the same formation as the lost limb. The endangered, aquatic, Mexican salamander are masters of regeneration, showcasing the best of an ability shared by many other amphibians, reptiles, and fish species. But how do these cold-blooded creatures do it? That some species can regrow limbs while others can't is one of the oldest mysteries in biology, says James Monaghan, a developmental biologist at Northeastern University. Aristotle noted that lizards can regenerate their tails more than 2,400 years ago, in one of the earliest known written observations of the phenomenon. And since the 18th century, a subset of biologists studying regeneration have been working to find a solution to the puzzle, in the hopes it will enable medical treatments that help human bodies behave more like axolotls. It may sound sci-fi, but Monaghan and others in his field firmly believe people might one day be able to grow back full arms and legs post-amputation. After all that time, the scientists are getting closer. Monaghan and a team of regeneration researchers have identified a critical molecular pathway that aids in limb mapping during regrowth, ensuring that axolotls' cells know how to piece themselves together in the same arrangement as before. Using gene-edited, glow-in-the-dark salamanders, the scientists parsed out the important role of a chemical called retinoic acid, a form of vitamin A and also the active ingredient in the acne medicine isotretinoin (commonly known as Accutane). The concentration of retinoic acid along the gradient of a developing replacement limb dictates where an axolotl's foot, joint, and leg segments go, according to the study published June 10 in the journal Nature Communications. Those concentrations are tightly controlled by just one protein also identified in the new work and, in turn, have a domino effect on a suite of other genes. 'This is really a question that has been fascinating developmental and regenerative biologists forever: How does the regenerating tissue know and make the blueprint of exactly what's missing?,' Catherine McCusker, a developmental biologist at the University of Massachusetts Boston who was uninvolved in the new research, tells Popular Science. The findings are 'exciting,' she says, because they show how even the low levels of retinoic acid naturally present in salamander tissues can have a major impact on limb formation. Previous work has examined the role of the vitamin A-adjacent molecule, but generally at artificially high dosages. The new study proves retinoic acid's relevance at normal concentrations. And, by identifying how retinoic acid is regulated as well as the subsequent effects of the compound in the molecular cascade, Monaghan and his colleagues have 'figured out something that's pretty far upstream' in the process of limb regeneration, says McCusker. Understanding these initial steps is a big part of decoding the rest of the process, she says. Once we know the complete chemical and genetic sequence that triggers regeneration, biomedical applications become more feasible. 'I really think that we'll be able to figure out how to regenerate human limbs,' McCusker says. 'I think it's a matter of time.' On the way there, she notes that findings could boost our ability to treat cancer, which can behave in similar ways to regenerating tissues, or enhance wound and burn healing. Monaghan and his colleagues started on their path to discovery by first assessing patterns of protein expression and retinoic acid concentration in salamander limbs. They used genetically modified axolotls that express proteins which fluoresce in the presence of the target compounds, so they could easily visualize where those molecules were present in the tissue under microscopes. Then, they used a drug to tamp down naturally occurring retinoic acid levels, and observed the effects on regenerating limbs. Finally, they produced a line of mutant salamanders lacking one of the genes in the chain, to pinpoint what alterations lead to which limb deformities. They found that higher concentrations of retinoic acid tell an Axolotl's body to keep growing leg length, while lower concentrations signal it's time to sprout a foot, according to the new research. Too much retinoic acid, and a limb can grow back deformed and extra-long, with segments and joints not present in a well-formed leg, hampering an axolotl's ability to easily move. One protein, in particular, is most important for setting the proper retinoic acid concentration. 'We discovered it's essentially a single enzyme called CYP26b1, that regulates the amount of tissue that regenerates,' Monaghan says. CYP26b1 breaks down retinoic acid, so when the gene that makes the protein is activated, retinoic acid concentrations drop, allowing the conditions for foot and digit formations. At least three additional genes vital to limb mapping and bone formation seem to be directly controlled by concentrations of retinoic acid. So, when retinoic acid concentrations are off, expression of these genes is also abnormal. Resulting limbs have shortened segments, repeat sections, limited bone development, and other deformations. Based on their observations, Monaghan posits that retinoic acid could be a tool for 'inducing regeneration.' There's 'probably not a silver bullet for regeneration,' he says, but adds that many pieces of the puzzle do seem to be wrapped up in the presence or absence of retinoic acid. 'It's shown promise before in the central nervous system and the spinal cord to induce regeneration. It's not out of the question to also [use it] to induce regeneration of a limb tissue.' Retinoic acid isn't just produced inside axolotls. It's a common biological compound made across animal species that plays many roles in the body. In human embryo development, retinoic acid pathways are what help map our bodily orientation, prompting a head to grow atop our shoulders instead of a tail. That's a big part of why isotretinoin can cause major birth defects if taken during pregnancy–because all that extra retinoic acid disrupts the normal developmental blueprint. Yet retinoic acid isn't the only notable factor shared by humans and amphibians alike. In fact, most of the genes identified as part of the axolotl limb regrowth process are also present in our own DNA. What's different seems to be how easily accessed those genetic mechanisms are after maturity. Axolotls, says Monaghan, have an uncanny ability to activate these developmental genes as needed. Much more research is needed to understand exactly how and why that is, and to get to the very root of regeneration ability, but the implication is that inducing human limbs to regrow could be easier than it sounds. 'We might not need to turn on thousands of genes or turn off thousands of genes or knock out genes. It might just be triggering the reprogramming of a cell into the proper state where it thinks it's an embryo,' he says. And lots of research is already underway. Other scientists, McCusker included, have also made big recent strides in attempting to unlock limb regeneration. Her lab published a study in April finding key mechanisms in the lateral mapping of limbs–how the top and bottom of a leg differentiate and grow. Another major study from scientists in Austria came out last month pinpointed genetic feedback loops involved in positional memory, which help axolotl tissues keep tabs on where lost limbs once were and how they should be structured. Still, it's likely to be decades more before human amputees can regain their limbs. Right now, the major findings fall in the realm of foundational science, says McCusker. Getting to the eventual goal of boosting human regenerative abilities will continue to take 'a huge investment and bit of trust.' But every medical treatment we have today was similarly built off of those fundamental building blocks, she says. 'We need to remember to continue to invest in these basic biology studies.' Otherwise, the vision of a more resilient future, where peoples' extremities can come back from severe injury, will remain out of reach.
