ears these genes may get activated again when there’s an injury. Exactly which genes and how their activation causes regrowth is the subject of ongoing research. Scientists have identified some candidate genes and are zooming in on what proteins are being expressed at each stage of limb regrowth. For now, they’re a long way from helping us regenerate limbs, but this potential means axolotls are very valuable to research. “It seems like there’s a clear end-state of development that the axolotl always wants to be in, so if anything in its body gets modified, it moves back towards that,” says Jeff. “Given that we have many developmental genes in common with axolotls, it would be very useful to humans if we could figure out exactly how they regenerate complex body parts.” An axolotl regrowing one of its front feet. © axolotlowner/ Shutterstock Are axolotls endangered? Given their primary habitat is so diminished, it’s no surprise that axolotls are listed by the International Union for Conservation of Nature as Critically Endangered . Their population is decreasing, with only 50-1,000 adults thought to be living in the wild. It was anticipated they might be extinct by 2020, but thankfully that hasn’t happened. Axolotls need deep water to thrive and plants to lay their eggs on. They’re sensitive to changes in water quality and urbanisation around their native lakes has led to pollution and habitat loss. People using the water can disturb these amphibians and new fish species introduced to the waterways, such as tilapia and carp, compete with the axolotls for food. Fish eat axolotls’ young too. Axolotls used to be taken from the wild for food and the pet trade, but all pets are now thought to be bred in captivity. Axolotls are sometimes known as a conservation paradox since they’re almost extinct in the wild, but are widely distributed in pet shops and labs throughout the world. However, this captive population is often very inbred, meaning there isn’t much genetic diversi

This regeneration is driven by a unique immune response that promotes healing and cellular dedifferentiation, allowing it to regrow complex tissues effectively. [1] In the wild axolotls are now near extinction (only about 50-1000 adult individuals).[2] This may be due to population growth in Mexico City, and the polluted waters of the lake. Non-native fish, such as African tilapia and Asian carp, have also recently been introduced to the waters. These new fish have been eating the axolotls' young, as well as its primary source of food.[3] The axolotl is currently on the IUCN Red List of threatened species (critically endangered as shown in the infobox).[4] Genetics and development Compared with land-dwelling salamanders, the sexually mature adult Axolotl is a chimera (mixture) of larval and adult tissues. A mutation in hormone production slows the development of the non-sexual tissues compared to the gonads.[1] So, it ends up as an adult which looks like a larva, except that it is sexually mature. This is an example of neoteny, a type of heterochrony.

Abstract Axolotls (Ambystoma mexicanum) are extensively studied for their relevance in human medical research. Despite being critically endangered in the wild, they have gained popularity as household pets. Although they have been kept in captivity for over a century, detailed descriptions of their coelomic organ anatomy remain limited. Also, this species exhibits significant variations compared to other amphibians. Ultrasound is a non-invasive and painless medical imaging technique, ideally suited for investigating internal organs or structures. This study focused on describing the ultrasound appearance of the axolotl coelomic cavity. It details the identification, localization and parenchymal description of major organs in 28 neotenic axolotls using ultrasound frequencies ranging from 7 to 15 MHz. The accuracy of the results was validated by comparing ultrasound findings with necropsy results from one male and one female axolotl. The heart, lung surface, liver and reproductive tracts were visualized. Measurements, along with confidence intervals, were calculated for the spleen, kidneys, testicles, gastric wall, gallbladder, and pylorus. Occasional detection of hyperechoic millimetric particles in the gallbladder or ascites was noted. However, visualization of the pancreas and bladder was not possible. This research outcomes involve the development of a comprehensive atlas comprising images obtained throughout the study. Additionally, the experiment established a reproducibl

Axolotls ( Ambystoma mexicanum ) are critically endangered paedomorphic salamanders with remarkable regenerative capacity. While nearly extinct in the wild, they are commonly maintained in captivity as companion animals, zoological display animals, and biomedical research colonies, where they serve as an animal model for genetics, developmental biology, and regenerative medicine. This report documents a case series of spontaneous myeloid leukemia in genetically related, co-housed adult axolotls in a zoological collection that resulted in 50% overall mortality over 38 months. Affected axolotls exhibited a range of signs, including generalized edema, hydrocoelom, long-term wasting, and sudden death. The most common gross lesions were splenomegaly (5/10) and hepatomegaly (4/10). Microscopically, widespread intravascular neoplasia, consisting of large round cells, was consistently observed (10/10). Neoplastic cells infiltrated and effaced the parenchyma of numerous visceral organs, particularly the spleen and liver. Cytochemical staining of neoplastic cells in blood smears showed strong positive cytoplasmic reactivity for α-naphthyl butyrate esterase and α-chloroacetate esterase and weak staining with periodic-acid Schiff. In tissues, neoplastic cells did not react with Sudan black B and did not express CD3 or ionized calcium-binding adaptor molecule 1 (IBA-1). The morphologic features of the cells and phenotyping tests supported acute myeloid leukemia. This report represents the

to roughly translate to “water monster” in the ancient Aztec language Nahuatl. — American Museum of Natural History ( Learn how Mexican nuns are helping to save axolotls. ) 5:22 See axolotls in the wild According to legend, this “water monster” was a god who disguised himself as a salamander to avoid sacrifice. Nowadays, it is critically endangered in the wild because of the pollution and urban sprawl that threaten its habitat in the Mexican Basin. Frequently asked questions Is it OK to have an axolotl as a pet? You can legally own one from a reputable breeder, supplier, or rescue organization. Some states in America prohibit owning even legally obtained exotic pets or require a permit. Axolotls bred in captivity are typically pink or white, instead of brown. — World Wildlife Fund Why can’t you touch axolotls? In general, you should not touch or handle axolotls unnecessarily. Their delicate skin is permeable, which means anything from natural oils to soap residue can cause harm. Additionally, their bodies are primarily made of cartilage, making them highly vulnerable to injury. — Environmental Literacy Council Do axolotls live in the U.S.? They are not native to the United States. They are endemic to southern Mexico City, in Xochimilco and Chalco Lakes. — The Natural History Museum U.K. Why did my axolotl turn into a salamander? It is extremely rare for wild axolotls to turn into salamanders. Environmental changes can cause a transformation and certain genetic traits can make some animals more prone to metamorphosis. In captivity, iodine or thyroid hormones can induce metamorphosis. However, doing so can cause stress and shorten the life of these fragile creatures, leading to ethical questions. Experts strongly discourage inducing metamorphosis. — Environmental Literacy Council Do axolotls have teeth? Yes, they have small, underdeveloped teeth. However, they eat by sucking in food. — PBS This story originally published on September 10, 2010. It was updated on June 1