--- title: Amphibian — Care & Reference Manual author: codebuddy type: manual llm_refined: true refined_by: kimi manual_v2: true date: 2026-08-04 source_topics: exotic_pet_profile_axolotl, exotic_pet_food_nrc_standard_map, exotic_nutrition_amphibian, exotic_nutrition_amphibian_live_prey, exotic_nutrition_axolotl, exotic_husbandry_amphibian_environment, exotic_husbandry_amphibian_quarantine, exotic_husbandry_axolotl, exotic_life_stage_amphibian, exotic_behavior_amphibian, exotic_enrichment_amphibian, exotic_grooming_amphibian, exotic_breeding_amphibian, exotic_amphibian_husbandry, exotic_tox_amphibian_metals, exotic_tox_amphibian_redleg, exotic_pet_legality_crosswalk_amphibian, evidence_exotic_amphibian_clinical, evidence_exotic_amphibian_husbandry_health, evidence_exotic_amphibian_toxicology, evidence_exotic_amphibian_nutrition, evidence_exotic_axolotl_nutrition source_hash: 421581453c906e2f draft: false --- # Amphibian — Care & Reference Manual *LLM-refined manual (v2 pipeline, kimi, 2026-08-04; docs/MANUAL_V2_DESIGN.md).* This manual assembles the verified fact blocks in Pet Data Station that mention *amphibian*, organised along a pet owner's journey. Every quoted fact is reproduced **verbatim** from its cited first-hand source (`[n]` superscripts; see References, each tagged with a computed trust grade per docs/topic_grading_guide.md) and is independently checkable. Guide sections (checklists, red-flag box) are orientation prose in which **every factual sentence carries its own `[n]`**; derived-summary blocks from non-Open-Access sources keep their *Paraphrased derived summary* mark. Mis-sectioned, duplicate, off-topic and image-residue fragments were removed by the v2 builder (build-gate enforced). ## Contents 1. [Species Profile](#species-profile) 2. [Life-Stage Care](#life-stage-care) 3. [Is this pet right for you?](#is-this-pet-right-for-you) 4. [Daily & Weekly Care Checklist](#daily-weekly-care-checklist) 5. [Nutrition](#nutrition) 6. [Husbandry](#husbandry) 7. [Behavior & Training](#behavior-training) 8. [Enrichment & Exercise](#enrichment-exercise) 9. [When to call a vet NOW](#when-to-call-a-vet-now) 10. [Health & Disease](#health-disease) 11. [Toxicology & Hazards](#toxicology-hazards) 12. [Grooming](#grooming) 13. [Breeding & Neutering](#breeding-neutering) 14. [Regulations & Legality](#regulations-legality) 15. [Appendix A — Commercial Food & Regulatory Notes](#appendix-a-commercial-food-regulatory-notes) 16. [Appendix B — Research Evidence](#appendix-b-research-evidence) ## Species Profile The profile below records this species' taxonomy, natural origin and lifespan as documented in the cited reference. ### Axolotl (Ambystoma mexicanum) — species profile (taxonomy, geographic range, habitat, physical description, behavior, wild diet, reproduction, lifespan) > Ambystoma mexicanum is historically found in Lakes Chalco and Xochimilco of the Valley of Mexico near Mexico City, Mexico. [1] > mexicanum are large, relatively permanent (until recently), high-altitude lakes located near Mexico City. [1] > Of the two lakes - Chalco and Xochimilco - where these animals are historically native, only Xochimilco (elevation: ~ 2,274 m) remains. [1] > Axolotls are almost extinct in their native habitat, largely due to the introduction of predatory fishes and habitat loss. [1] > Axolotls are paedomorphic or neotenic aquatic salamanders, meaning they retain certain larval characteristics in the adult, reproductive state. [1] > They possess feathery external gills and finned tails for swimming. [1] > Laboratory animals exist in several color morphs, ranging from wild type (dark, mottled brownish-green) to albino. [1] > Axolotls reach lengths on average of 20 cm (9 inches), but can grow to more than 30 cm (12 inches) in length. [1] > Axolotls are solitary and may be active at any time of the day. [1] > At other times of the year there is little to no intraspecific communication. [1] > Axolotls can detect electrical fields and also use their vision and chemical cues to perceive their environment and discover prey. [1] > Generally the top predator in their natural environment, axolotls will eat anything that they can catch, including molluscs, fishes, and arthropods, as well as conspecifics. [1] > mexicanum follows the general Ambystoma pattern; it first involes each animal nudging the other's cloacal region, eventually leading to a "waltz," with both animals moving in a circle. [1] > Next, the male moves away while undulating the posterior part of his body and tail (resembling a "hula dance"), and the female follows. [1] > The male will deposit a spermatophore (a cone-shaped jelly mass with a sperm cap) by vigorously shaking his tail for about half a minute, and will then move forward one body length. [1] > mexicanum is paedomorphic, which means that it retains larval characteristics in the reproductively mature adult form. [1] > Juvenile and adult axolotls possess feathery, external gills and tail fins suited to an aquatic lifestyle. [1] > Metamorphosis can be induced in axolotls via thyroid hormone injections. [1] > Axolotls were the top predator in their native environment, making them important in structuring community dynamics. [1] > Axolotls may be preyed on by large fish and conspecifics. [1] > Large fish have only recently been introduced into the lakes where axolotls are found, contributing to the demise of their populations. [1] > mexicanum is nearly gone. [1] > Historically, they have been known to live in high altitude lakes near Mexico City. [1] > Expected laboratory longevity is 5 to 6 years; however, some animals have been known to live as long as 10 to 15 years. [1] ## Life-Stage Care Young, adult and senior care for this species, drawn from first-hand care pages and veterinary references. ### Amphibian — life stage (owner-practical care, Merck Veterinary Manual pet-owner) *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Adult terrestrial and aquatic amphibians typically eat invertebrates — earthworms, bloodworms, black worms (mainly aquatic), white worms (aquatic/semiaquatic), tubifex worms, springtails, fruit flies, fly larvae, mealworms, and crickets. [2] > Adult amphibians breathe both through lungs and through their skin, which must remain moist for gas exchange. [2] ## Is this pet right for you? - **They live fully in water:** axolotls (Ambystoma mexicanum) are paedomorphic (neotenic) aquatic salamanders that keep larval traits — feathery external gills and a finned tail — as reproducing adults, so they need an aquarium, not a terrarium. [1] - **They are solitary and private:** axolotls are solitary and may be active at any time of the day. [1] - **Size:** axolotls average about 20 cm (9 in) and can grow to more than 30 cm (12 in). [1] - **Delicate skin, minimal handling:** amphibian skin absorbs water readily and therefore also absorbs toxins, so they are good pets but should be handled minimally because their skin is delicate. [2] - **They depend on a stable environment:** their metabolism and immune function are uniquely reliant on a stable environment, so the enclosure must hold a steady, moist, toxin-free set-up. [3] - **Conservation note:** wild axolotls are almost extinct in their native habitat (due to predatory fish and habitat loss), so responsible captive care matters. [1] ## Daily & Weekly Care Checklist Every day: - **Live food:** most captive amphibians need live food long-term — adult terrestrial and aquatic species mostly eat invertebrates (earthworms, bloodworms, black/white/tubifex worms, springtails, fruit flies, fly larvae, mealworms, crickets). [4] - **Supplements:** vitamin and mineral supplements are needed to prevent nutritional disease; deliver them by gut-loading insects, calcium-rich diets, or dusting with a D3/calcium powder, and add a vitamin A source because amphibians cannot make carotenoids. [4] - **Clean water:** water must be clean and free of toxins such as chlorine, ammonia, nitrite, pesticides and heavy metals; remove chlorine by circulating tap water through a carbon filter for ≥24 hours before use. [3] - **Moisture + temperature:** keep skin moist (mist, humidifier, or small streams/waterfalls) and spot-check the enclosure daily with a temperature probe; provide a thermal gradient within the species' preferred optimal temperature zone (POTZ). [2] [3] - **Housing:** aquatic amphibians (e.g. axolotls) go in aquariums with swimming areas; terrestrial amphibians need a shallow water container in the enclosure. [3] - **Handle only when necessary:** skin is delicate and absorbs toxins, so keep handling to a minimum. [2] Every week: - **Water change:** in established aquatic tanks, change at least 10% of the water each week. [2] - **Substrate:** spot-clean floor substrate daily to weekly and replace it fully every few weeks to months depending on the material. [2] - **Temperature:** tailed amphibians (caudatans, like axolotls) prefer noticeably cooler temperatures than tailless ones (anurans, like frogs) — keep the gradient in the right range. [3] ## Nutrition The short version: most captive amphibians need live invertebrate food long-term, with vitamin/mineral supplements (gut-loading or dusting with D3/calcium, plus a vitamin A source because they cannot make carotenoids); some larger species also take vertebrate prey such as live minnows or neonatal mice. [4] The sourced details follow. The quotes below summarise this species' dietary requirements and nutrition-related disease risks, drawn from professional veterinary references. ### Amphibian nutrition — captive amphibians require live food and vitamin/mineral supplementation *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Most captive amphibians need live food long-term. [3] > Adult terrestrial and aquatic amphibians mostly eat invertebrates — earthworms, bloodworms, black/white/tubifex worms, springtails, fruit flies, fly larvae, mealworms, and crickets. [3] > Vitamin and mineral supplements prevent nutritional disease. [3] > Tropical amphibians in poor conditions often develop infectious or nutritional disease. [3] > Aquatic plants oxygenate and clean water, offer cover, and often feed larval amphibians. [3] > UVB (280–320 nm) likely aids calcium metabolism and color vision in diurnal amphibians, though its benefits are not fully clear. [3] > Glass blocks UVB, so lamps must be placed to avoid that barrier. [3] > Some amphibians eat vertebrates — live minnows, guppies, goldfish, or neonatal mice or rats. [3] > Calcium and vitamins are delivered by gut-loading insects, using calcium-rich diets, or dusting insects with D3/calcium powder. [3] > Amphibians cannot make carotenoids, so a vitamin A source must be added. [3] > Useful diagnostics include fecal exams, water testing, skin scrapes, PCR (e.g., chytrid, ranavirus), gill biopsies, and bloodwork when feasible. [3] ### Amphibian nutrition — live-prey feeding, supplements, and dusting/gut-loading *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Most adult amphibians, whether land or water-dwelling, eat invertebrates such as earthworms, bloodworms, blackworms, whiteworms, tubifex worms, springtails, fruit flies, fly larvae, mealworms and crickets. [4] > Some species also take vertebrate prey and need live minnows, guppies, goldfish or newborn mice and rats. [4] > Vitamin and mineral supplementation is needed to avoid nutritional disease. [4] > Supplements are usually given by gut-loading feeder insects, using calcium-rich commercial diets, or dusting insects with a vitamin-and-calcium powder that contains vitamin D3. [4] ### Nutrition of axolotls and other amphibians (Merck): live prey, supplements > feed on invertebrates, including earthworms, bloodworms, black worms, white worms, tubifex worms, springtails, fruit flies, fly larvae, mealworms, and crickets. [3] > Some amphibians feed on vertebrates and require live minnows, guppies, goldfish, or neonatal mice or rats. [3] > Vitamin and mineral supplements are necessary to prevent nutritional disease. These are commonly administered by gut loading insects, using commercially available diets high in calcium or by coating insects with powdered, multiple-vitamin preparations that include vitamin D 3 and calcium (also known as dusting). [3] > *[Paraphrased derived summary — non-Open-Access source.]* Most invertebrates lack the right calcium-to-phosphorus ratio (earthworms are an exception) and often miss key vitamins, so they do not by themselves support healthy bone growth. [2] > Supplements are usually given by gut-loading insects, using calcium-rich commercial diets, or dusting insects with powdered multivitamins that include vitamin D3 and calcium. ## Husbandry The home is an enclosure with a stable thermal gradient (POTZ), clean toxin-free water, and moisture — aquatic species in aquariums, terrestrial ones with a shallow water dish; spot-clean daily and change 10% of tank water weekly. [3] [2] The sourced details follow. Housing, environment and daily-care essentials for this species. ### Amphibian environment — desiccation risk if enclosure care inadequate *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Amphibians that escape their enclosure or receive poor care commonly become dehydrated (desiccate), because they readily lose moisture through their skin. [4] ### Amphibian quarantine — 6–8 weeks recommended before joining collection *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Quarantine is a preventive-medicine step owners should be advised to use; it is often skipped, letting disease into captive groups. The period should reflect the collection's risk and the animal's source, but 6–8 weeks is usually enough. [4] ### Husbandry of axolotls and other amphibians (Merck): cool thermal gradient, water temperature > The POTZ of amphibian species is generally less than the POTZ of reptilians; caudatan species prefer temperatures substantially lower than anuran species. [3] > Water temperature regulation with water chillers and air conditioning must be considered for enclosures. [3] > Provision of a thermal gradient within a species POTZ allows most amphibians to self-regulate body temperature. [3] > DVCertAq Due to amphibians’ unique integument and physiology, their metabolism and immune function is uniquely reliant on a stable environment. [3] > Infectious and nutritional diseases are common problems in tropical amphibians kept in suboptimal conditions. [3] > The range of temperatures necessary for proper metabolism, called the preferred optimal temperature zone (POTZ), varies among species. [3] > Enclosures should be spot-checked daily with a laser temperature probe, which can be purchased at most hardware or pet stores. [3] > Aquatic amphibians may be accommodated in aquariums with areas for swimming. [3] > Terrestrial amphibians need a shallow container of water in the enclosure. [3] > Moisture may also be provided by incorporating small streams, waterfalls, or ultrasonic humidifiers into enclosures, or by misting frequently with a spray bottle. [3] > Organic substrates and refugia that limit water loss can also help provide humidity within microhabitats. [3] > Water must be clean and free of toxins such as chlorine, ammonia, nitrite, pesticides, and heavy metals. [3] > Chlorine can be removed from tap water by placing the water in a container and circulating it through a carbon filter for ≥ 24 hours before use. [3] > The chloramine bond must be split with specific dechlorinating agents (eg, sodium thiosulfate), after which water can be filtered with carbon to remove the chlorine. [3] > *[Paraphrased derived summary — non-Open-Access source.]* Depending on the species, floor substrates can include gravel, soil, sphagnum moss, and mulch. [2] > *[Paraphrased derived summary — non-Open-Access source.]* Spot-clean floor substrate daily to weekly, and replace it fully every few weeks to months depending on the material. [2] > Suitable substrates include gravel, soil, sphagnum moss, and mulch. > Substrates may be frozen to help eliminate pests, and enclosures need adequate ventilation (1–2 fresh air changes per hour) to prevent disease. > *[Paraphrased derived summary — non-Open-Access source.]* Mosses, hardwood mulches, and soil support beneficial microorganisms, so keep a small portion of these substrates in place during each cleaning. [2] ## Behavior & Training Axolotls are solitary, aquatic (natatorial) animals that may be active by day or night and communicate mainly via visual and chemical cues during mating. [1] The sourced details follow. Socialisation, bonding, play and preventing boredom / behaviour problems. ### Amphibian behavior — class-level overview (activity patterns, communication, skin sensitivity, foraging, thermal behavior) > Key Behaviors: natatorial; diurnal; nocturnal; motile; sedentary; solitary. ## Enrichment & Exercise Toys, foraging, hiding and exercise to prevent boredom. ### Amphibian enrichment — class-level overview (substrate, environmental choice, feeding variety) > Heating soil to 93°C for 30 minutes is recommended to kill arthropods such as trombiculid mites and helminth parasites. > Giving amphibians a thermal gradient within their preferred optimal temperature zone (POTZ) lets most species regulate their own body temperature. > Most adult terrestrial and aquatic amphibians eat invertebrates — earthworms, bloodworms, black worms, white worms, tubifex worms, springtails, fruit flies, fly larvae, mealworms, and crickets. ## When to call a vet NOW - **They decline fast in a bad environment:** amphibian skin absorbs toxins readily and their health relies on a stable environment, so water-quality or temperature problems can make them sick quickly — act promptly. [2] [3] - **Reddened belly skin or lesions:** these can signal red-leg syndrome (bacterial dermatosepticemia) and may also reflect toxemia, ranavirus, or chytridiomycosis — contact a vet; lesions usually respond to antimicrobials but infection can spread systemically. [5] - **Dehydration / desiccation:** amphibians lose moisture through their skin, and escapees or poor care commonly cause dehydration — rehouse the animal and check it; dehydration is a real emergency. [3] - **New arrivals:** quarantine new animals 6–8 weeks and have a vet do entry and exit exams, so disease does not enter the collection. [4] ## Health & Disease The recurring themes: delicate, toxin-absorbing skin; reliance on a stable environment; red-leg syndrome plus chytrid/ranavirus as real threats; and a 6–8 week quarantine to keep disease out of a collection. [2] [5] [4] The sourced details follow. Common conditions and their clinical signs, drawn from professional veterinary references. If you notice worrying signs, contact a species-experienced veterinarian promptly. ### Amphibian husbandry — species POTZ thermal gradient for self-regulation; caudatans cooler than anurans *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Tailed amphibians (caudatans, e.g. salamanders) prefer noticeably cooler temperatures than tailless ones (anurans, e.g. frogs). [3] > Infectious and nutritional diseases are common in tropical amphibians kept in poor conditions. [3] > Some municipal tap water contains chloramines. [3] > Vitamin and mineral supplements are needed to prevent nutritional disease. [3] > Quarantine is often neglected, which can introduce disease into a captive collection; owners should be advised to use it. [3] > Veterinarians should perform a postmortem and consider histology for amphibians that die in quarantine. [3] > During quarantine, regular veterinary checks should include at least an entry and an exit examination. [3] > Useful quarantine diagnostics include faecal parasite exams, water-quality testing, skin scrapes of abnormal areas, PCR (e.g. for chytridiomycosis or ranavirus), gill biopsies, and bloodwork when the animal is large enough. [3] ## Toxicology & Hazards Substances and environmental hazards to avoid. ### Metal (Cu, Cd, Zn, Ni, Pb) contaminant toxicity in amphibian tadpoles — environmental hazard > Amphibians are highly vulnerable to environmental pollutants, especially during the larval stage, when temperature fluctuations in ephemeral ponds can interact with metals and alter their toxicity, a scenario that may be intensified by ongoing climate change. [6] > This study investigated the toxicity of five metals on tadpoles of Rhinella diptycha and Leptodactylus fuscus, across two different temperatures (28 and 34 °C). [6] > Species sensitivity distribution (SSD) curves were then constructed for each metal using LC50 data for both tropical species, together with those from the literature on other tadpole and standard fish species. [6] > In almost all cases, increased temperature enhanced metal toxicity in a dose-dependent effect. [6] > fuscus as among the most sensitive species to metals. [6] > Our findings show that metal toxicity can be amplified at higher temperatures, reinforcing the importance of accounting for temperature effects when establishing safe environmental concentrations of potential contaminants, particularly for species inhabiting warmer areas. [6] > Metals are naturally occurring elements in the environment that can be found in several compartments, including aquatic ecosystems. [6] > At low concentrations, metals such as iron (Fe), copper (Cu), and manganese (Mn) play beneficial roles for most organisms, as they are essential for various biochemical and physiological processes. [6] > However, several anthropogenic activities, such as agriculture, mining, and industrial processes, can increase metal concentrations in natural systems, making them some of the most widespread contaminants on the planet (Aigberua et al. [6] ### Red-leg syndrome (bacterial dermatosepticemia) precipitated by poor water / environmental quality in amphibians *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Quarantine is often skipped, letting disease into captive groups. [5] > Lesions usually respond to antimicrobials; sometimes surgical debridement is needed. [5] > Chlamydial infection may respond to doxycycline (5–10 mg/kg PO daily for 10–14 days) or oxytetracycline (50 mg/kg PO daily for 10–14 days). [5] > Though often skin-based, infection can also reach the gut and spread systemically. [5] > Culture helps guide antimicrobial choice. [5] > Reddened belly skin is a nonspecific sign that can also reflect toxemia, ranavirus, or chytridiomycosis. [5] > *[Paraphrased derived summary — non-Open-Access source.]* Untreated hardwood mulches and leaf litter are options, but avoid cedar and pine, which contain toxic oils. [2] ## Grooming Brushing / bathing, nails, coat / skin and dental care. ### Amphibian — grooming (owner-practical care, Merck Veterinary Manual pet-owner) *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > Some aquatic amphibians need gentle filtration that cleans the water without strong currents. [2] > Amphibian skin absorbs water readily, and therefore also absorbs toxins. [2] > In established aquatic tanks, change at least 10% of the water each week. [2] > Most amphibians have moist skin covered by a mucus film (the slime layer). [2] > Amphibians can be good pets but should be handled minimally because their skin is delicate. [2] ## Breeding & Neutering Neutering / spaying, reproduction and preventing unwanted litters. ### Amphibian — breeding (owner-practical care, Merck Veterinary Manual pet-owner) *All lines in this block are paraphrased derived summaries — non-Open-Access source.* > To reduce pests, heat soil to 200°F (93°C) for 30 minutes or freeze it below 32°F (0°C). [2] > Not all plants are safe for amphibians, so consult an experienced owner, breeder, or vet before adding any. [2] > Not every 'full-spectrum' (sunlight-mimicking) bulb supplies proper UVB, so ask a knowledgeable vet or breeder which to use. [2] > Axolotls communicate mainly via visual cues and chemical cues during mating. [1] ## Regulations & Legality Legality crosswalk lines for this species, where available. Jurisdiction-specific pet law is frequently a gap — see the roadmap. ### Amphibian — species legality crosswalk (US/CA/FL named lists + EU/JP/CITES framework) > all species in the genera Ambystoma, Andrias, Aneides, Aquiloeurycea, Calotriton, Chioglossa, Chiropterotriton, Cryptobranchus, Cynops, Desmognathus, Ensatina, Euproctus, Eurycea, Hydromantes, Hynobius, Ichthyosaura, Laotriton, Lissotriton, Neurergus, Notophthalmus, Ommatotriton, Onychodactylus, Pachytriton, Paramesotriton, Plethodon, Pleurodeles, Proteus, Pseudobranchus, Pseudotriton, Salamandra, Salamandrella, Salamandrina, Siren, Taricha, Triturus, and Tylototriton is prohibited except as provided under the terms and conditions set forth at § 16.22 of this part. ## Appendix A — Commercial Food & Regulatory Notes How pet-food regulatory standards treat this species (reference material, demoted from the main flow). ### Exotic / specialty pet food — AAFCO recognizes no nutrient profiles for exotics; standards defer to NRC species reports > As an AAFCO-recognized nutrient profile or nutritional authority: [7] > For dogs, the AAFCO Dog Food Nutrient Profiles; [7] > For cats, the AAFCO Cat Food Nutrient Profiles; [7] > For specialty pets, the nutrient recommendations approved by the Committee on Animal Nutrition of the National Research Council of the National Academy of Sciences [7] ## Appendix B — Research Evidence Peer-reviewed papers indexed for this species (reference material). Entries whose abstract did not mention the species by name, or were flagged off-topic at source, were omitted as likely mis-clustered. ### Evidence cluster — Pet amphibian (anuran) clinical cases (peer-reviewed, Europe PMC) > **PMID 42117820 (2026, Biology)** — Leech Diversity in the Maghreb (North Africa): A Checklist and a Case Report of Parasitism on a Berber Toad (Sclerophys mauritanica) in Algeria. (opening): Leeches (Hirudinea) are ecologically important annelids that interact with a wide range of aquatic vertebrates, yet their diversity, distribution, and epidemiological relevance remain poorly documented in North Africa. Here, we provide a comprehensive synthesis of freshwater and marine leech species reported from the Maghreb (Algeria, Tunisia, and Morocco), based on an extensive review of the available literature. In total, 21 species belonging to 13 genera and four families (Glossiphoniidae, Erpobdellidae, Hirudinidae, and Piscicolidae) are documented, with updated information on their ecology, host associations, and geographic distribution. In addition to this regional checklist, we report the first confirmed case of Batracobdella algira heavy parasitism on the Berber toad ( Sclerophrys mauritanica ) in Algeria. A single adult toad was found heavily infested by multiple leeches ( n = 17), some of which bore spermatophores attached near the reproductive opercula, suggesting possible in situ mating behavior on the host. The high infestation observed in this single specimen may constitute an outlier, requiring further sampling to assess the effect of leeches on the anuran population in the region. By integrating faunistic data with a novel field observation, this study highlights the overlooked leech biodiversity in the Maghreb and suggests their possible ecological and epidemiological significance. Our findings emphasize the need for further investigations into leech-host interactions, pathogen carriage, and their implications for amphibian conservation and One Health in North Africa. [8] > **PMID 42101880 (2026, Integrative and comparative biology)** — Activity Responses of Rana forreri and Rhinella horribilis Tadpoles to Predation Cues. (opening): Tadpoles must rapidly detect and respond to predation cues to survive the most vulnerable stage of anuran development. Although previous studies have examined the effects of visual or chemical cues on tadpole behavior, none have compared the effects of multiple predator-associated sensory stimuli across species. Here, we examined the responses of two neotropical tadpole species, the Forrer's leopard frog Rana forreri (non-toxic), and the cane toad Rhinella horribilis (toxic), to visual, chemical, and auditory predation cues. Tadpoles were exposed to simulated bird shadows (visual cue), belostomatid-conditioned water (chemical cue), and calls of the Green Kingfisher predator, Chloroceryle americana (auditory cue). We recorded tadpole activity for 4 min prior to, 1 min during, and 4 min following treatment exposure using portable locomotion activity monitors (pLAMs). Rana forreri exhibited increased activity in response to auditory cues, whereas chemical and visual cues did not produce significant changes in activity levels relative to the control. Conversely, R. horribilis showed no significant differences in activity level across treatments. These findings suggest that antipredation responses vary in their sensitivity to sensory modality and may be shaped by species-specific defensive strategies. In particular, chemical defense may reduce reliance on immediate behavioral responses, while non-toxic species may exhibit stronger responsiveness to specific sensory cues. Together, our results highlight the selective prioritization of sensory information in shaping antipredation behavior in larval anurans. [9] > **PMID 40539017 (2025, International journal for parasitology. Parasites and wildlife)** — First report of flesh-fly (Diptera: Sarcophagidae) myiasis in little-devil poison frog (Anura: Dendrobatidae) from Ecuador. (opening): We report a case of myiasis in the poison frog Oophaga sylvatica from the Canandé Reserve located in the Chocó region of northwestern Ecuador. We identified the causal agents as larvae of flesh flies, Sarcophagidae, by means of DNA barcoding and morphological features. This represents the first record of myiasis in an anuran in Ecuador and the second record for Dendrobatidae in the Neotropics. This observation may constitute a case of facultative parasitism where larvae are deposited in the frog's wounds, but further research is needed to understand the biological mechanisms underlying this interaction. [10] > **PMID 40873727 (2025, Ecology and evolution)** — Chemical Interference: A Review on Endocrine Disruptors and Reproductive Communication in Amphibians. (opening): Amphibians are highly vulnerable to anthropogenic pollution, primarily due to their permeable skin and eggs, as well as their habitat preferences. Endocrine-disrupting compounds (EDCs), prevalent in aquatic environments and soil, pose a significant threat to their survival. While the physiological effects of EDCs on amphibians have been extensively studied, their impact on behavior remains relatively unexplored. This paper reviews the existing literature on the impact of EDCs on the mating behavior of amphibians, including disruptions in acoustic, olfactory, and visual communication. Although it has been shown that amphibian reproduction can be affected by endocrine disruptors, there are still significant research gaps. We performed an extensive review of the literature, which yielded only 27 eligible studies-21 of which tested the effects on mating communication and behavior, and only 6 examined the impact on body coloration. There is a strong need for a deeper understanding of how EDCs, both alone and in combination with other stressors, affect the reproductive behavior of amphibians, as this may have serious implications for the dynamics and survival of entire populations and species. [11] > **PMID 38818027 (2024, Biology methods & protocols)** — Comparing skin swabs, buccal swabs, and toe clips for amphibian genetic sampling, a case study with a small anuran ( Acris blanchardi ). (opening): Multiple methods for collecting genetic samples from amphibians exist, each with their own implications for study design, animal welfare, and costs. Toe clipping is one common method, but there is ongoing debate regarding its potential detriment. Less invasive methods should be implemented, if efficacious, as amphibians are a particularly vulnerable vertebrate group. Skin and buccal swabbing are less invasive methods for genetic sampling, but the potential for contamination and a lower yield of DNA may exist. To compare these methods, we gathered skin swabs, buccal swabs, and toe clips from the same individuals of a relatively small anuran species, Blanchard's Cricket Frog ( Acris blanchardi ). We then compared DNA yield, DNA purity, amplification success rate, and genotypic data quality among sample types. We found toe clips and buccal swabs generated similar DNA yield and purity, with skin swabs yielding significantly less DNA of significantly lower purity than the other sample types. Amplification success rate was significantly higher using toe clips compared to the other sample types, though buccal swab samples amplified more readily than skin swabs. Genotypic data from toe clips and buccal swabs did not differ significantly in quality, but skin swab data quality was significantly lowest among sample types. Thus, skin swabbing could produce erroneous data in some situations, but buccal swabbing is likely an effective substitute to toe clipping, even for small species. Our results can help future researchers select which genetic sampling method might best suit their research needs. [12] > **PMID 38354202 (2024, PLoS computational biology)** — Enhancing predictive performance for spectroscopic studies in wildlife science through a multi-model approach: A case study for species classification of live amphibians. (opening): Near infrared spectroscopy coupled with predictive modeling is a growing field of study for addressing questions in wildlife science aimed at improving management strategies and conservation outcomes for managed and threatened fauna. To date, the majority of spectroscopic studies in wildlife and fisheries applied chemometrics and predictive modeling with a single-algorithm approach. By contrast, multi-model approaches are used routinely for analyzing spectroscopic datasets across many major industries (e.g., medicine, agriculture) to maximize predictive outcomes for real-world applications. In this study, we conducted a benchmark modeling exercise to compare the performance of several machine learning algorithms in a multi-class problem utilizing a multivariate spectroscopic dataset obtained from live animals. Spectra obtained from live individuals representing eleven amphibian species were classified according to taxonomic designation. Seven modeling techniques were applied to generate prediction models, which varied significantly (p < 0.05) with regard to mean classification accuracy (e.g., support vector machine: 95.8 ± 0.8% vs. K-nearest neighbors: 89.3 ± 1.0%). Through the use of a multi-algorithm approach, candidate algorithms can be identified and applied to more effectively model complex spectroscopic data collected for wildlife sciences. Other key considerations in the predictive modeling workflow that serve to optimize spectroscopic model performance (e.g., variable selection and cross-validation procedures) are also discussed. [13] > **PMID 39052625 (2024, PloS one)** — Oral administration of GnRH via a cricket vehicle stimulates spermiation in tiger salamanders (Ambystoma tigrinum). (opening): More than 50% of caudates are threatened with extinction and are in need of ex-situ breeding programs to support conservation efforts and species recovery. Unfortunately, many salamander populations under human care can experience reproductive failure, primarily due to missing environmental cues necessary for breeding. Assisted reproductive technologies (ARTs) are a useful suite of techniques for overcoming or bypassing these missing environmental cues to promote breeding. Exogenous hormones are used to stimulate natural breeding behaviors or gamete expression for in-vitro fertilization or biobanking and are typically administered intramuscularly in caudates. While effective, intramuscular injection is risky to perform in smaller-bodied animals, resulting in health and welfare risks. This research investigated the spermiation response to hormone administration through a non-invasive oral bioencapsulation route using the tiger salamander (Ambystoma tigrinum) as a model species. Male salamanders were randomly rotated six weeks apart through four treatments (n = 11 males/treatment) in which animals received a resolving dose of gonadotropin-releasing hormone (GnRH) as follows: (1) Prime-Only (0.0 μg/g); (2) Low (0.25 μg/g); (3) Medium (1.0 μg/g); and (4) High (2.0 μg/g). All males were given a GnRH priming dose (0.25 μg/g) 24 hours prior to the resolving dose. Exogenous hormone was delivered inside of a cricket (Gryllodes sigillatus) that was presented as a food item by tweezers. Sperm samples were collected at 1, 3, 6, 9, 12, and 24 hours after the resolving dose and analyzed for quantity and quality. For all treatments, sperm concentration was produced in an episodic pattern over time. The Prime-Only treatment had a lower (p < 0.05) percent of sperm exhibiting normal morphology compared to treatments utilizing a resolving dose of GnRH. Overall, oral administration of GnRH is a feasible route of inducing spermiation in salamanders, yielding sperm of sufficient quantity and quality for in-vitro fertilization and biobanking efforts. [14] ### Evidence cluster — Pet amphibian (anuran) husbandry, health & nutrition (peer-reviewed, Europe PMC) > **PMID 41524647 (2026, Integrative zoology)** — *[Paraphrased derived summary — non-Open-Access source.]* A latitudinal survey (22–43°S, 40 localities) of the four-eyed frog Pleurodema thaul in Chile found hemoparasites in 61% (221/363) of individuals, identifying Hepatozoon sp. (7%), Dactylosoma sp. (39%), and Lankesterella sp. (22%) via Giemsa-stained blood smears. The study documents these parasites' morphology and local host–parasite interactions across the species' Chilean range. [15] > **PMID 42126746 (2026, Acta parasitologica)** — *[Paraphrased derived summary — non-Open-Access source.]* Surveying 102 anurans across 20 native Japanese frog species revealed a Sphaerospora myxosporean parasitizing the kidneys of the Japanese rice frog (Fejervarya kawamurai), described as a new species (spores 11.1×11.5 µm, polar capsules ~3.3 µm, caudal appendage). It is the first East Asian record of an anuran-parasitic Sphaerospora and the fifth globally, placed phylogenetically among Palaearctic, Afrotropical, Nearctic, and Neotropical anuran-parasitic taxa. (Borderline: amphibian parasite taxonomy, loosely relevant to health.) [16] > **PMID 42015311 (2026, Parasites & vectors)** — Culex territans mosquitoes as a vector of Giant Anuran Trypanosomes. (opening): Background Amphibian populations are declining worldwide, in part due to diseases caused by viruses, fungi, andparasites. Giant Anuran Trypanosomes (GATs) are parasites that affect frogs worldwide and require a vector to betransmitted. Culex territans is an amphibian-feeding mosquito suspected to be a vector of trypanosomes, but this hasnot previously been confirmed. Methods In this study, we tested blood-fed Cx. territans and blood from their primary anuran hosts, Rana clamitans and R. catesbeiana, in southwest Virginia. Additionally, we tested potential routes of transmission from the mosquito tothe frog. Results We found trypanosomes present in both mosquitoes and anurans and found trypanosomes present in thefeces 2 days after being blood fed on infected frogs, as well as in the body and saliva 14 days post-feeding. Conclusions Overall, this study contributes to our knowledge of the GAT epidemiology and the role Cx. territans mightplay in their transmission. *[CC BY — Open Access, verbatim with attribution.]* [17] > **PMID 42311595 (2026, Ecology and evolution)** — Variations in Sexual Size Dimorphism in Two Anurans Along an Urbanization Gradient in Shanghai: Assessment of Rensch's Rule. (opening): Variations in sexual size dimorphism (SSD) have important consequences for animal ecology, behavior, population dynamics, and the evolution of life-history traits, and can be explained by many intraspecific and interpopulation hypotheses. Urbanization is an important factor that affects anuran phenotypic characteristics (including morphology), but how it impacts anuran SSD has been explored less widely. In this study, we aimed to investigate the differences in SSD in two dominant amphibian species populations; that is, the Hong Kong rice-paddy frog ( Fejervarya multistriata ) and Beijing gold-striped pond frog ( Pelophylax plancyi ), across an urban-rural gradient in Shanghai (including urban, suburban, and rural areas). We also tested whether these variations in SSD supported Rensch's rule or not. Our results showed that in both sexes, the snout-vent length (SVL) in F. multistriata was higher in urban areas compared with suburban and rural areas. In addition, only male P. plancyi exhibited a higher SVL in urban areas compared with those in rural areas. Furthermore, we found that the SSD in SVL was significantly higher for urban populations than suburban and rural populations of F. multistriata. All SSD results in terms of SVL, head width, forelimb length, and hindlimb length in these two frog species supported the inverse Rensch's rule based on reduced major axis regression. Moreover, the size scaling rates in these two frog species were higher in urban and suburban populations than rural populations. Thus, we concluded that urbanization shapes SSD in these two anurans according to the inverse of Rensch's rule, and that variations in morphological characteristics, SSD, and size scaling rates differed between these two anuran species regarded as an "urban-associated species" ( P. plancyi ) and "urban-sensitive species" ( F. multistriata ). *[CC BY — Open Access, verbatim with attribution.]* [18] > **PMID 41766740 (2026, Ecology and evolution)** — A Review of the Scale and Sustainability of the Consumption and Trade of Anuran Species in Africa. (opening): Within Africa, collection and trade of anurans is often recorded as single-site case studies, making it difficult to accurately understand the scale of use, its livelihood importance, and impact on species. We conducted a systematic review to: compile literature on anuran uses in Africa; identify the species and ecoregions involved; and identify gaps and opportunities for monitoring anuran utilisation. From an initial pool of 3335 articles, 85 studies on anuran use were reviewed. We augmented this with data from records on levels of anuran trade within CITES from 2012 to 2021, IUCN redlist, UNdata and WILDMEAT databases. We found 131 amphibian (124 anuran) species belonging to 18 families and 42 genera used within Africa. About 31.5% of species are used as food and 2.4% used in traditional medicine. Another 23.4% are used in multiple ways. Larger-bodied species, including Hoplobatrachus occipitalis and Pyxicephalus edulis, are most preferred as food, whereas smaller and colourful ones (mostly in the Mantellidae family) are traded as pets. The use of anurans as food and traditional medicine is concentrated in Guineo-Congolian and Guineo-Sudanian ecoregions, whilst Madagascar and the Indian Ocean dominates the international pet trade. Wild populations of anuran species are collected mainly by local men and sold to intermediaries to supply food and pet markets. African countries import frog legs more than they export possibly, to supply locally based international restaurants. We identified the inability of most international databases to accurately capture the extent of anuran use with literature review identifying 28 additional species missed by these platforms. Also, there are few scientific studies that quantify the impacts of use on anurans in Africa. Synthesis and applications: We recommend that anuran species collection and trade be incorporated into national biodiversity monitoring plans. *[CC BY — Open Access, verbatim with attribution.]* [19] > **PMID 42528927 (2026, Biology methods & protocols)** — *[Paraphrased derived summary — non-Open-Access source.]* To enable non-lethal amphibian genetic sampling in India, researchers tested skin swabs across multiple anuran species, comparing salt vs kit DNA extraction and dry vs wet storage. Kit extraction gave ideal purity (A260/280 = 1.8–2.0); storage condition did not affect DNA concentration but dry swabs gave higher purity; 86% amplified on gel and 67% yielded high-quality sequences. The authors present minimally invasive skin swabbing as a replicable anuran research/conservation method. (Borderline: genetic-sampling methodology rather than husbandry/health, but relevant to non-invasive amphibian work.) [20] ### Evidence cluster — Pet amphibian (anuran) toxicology (peer-reviewed, Europe PMC) > **PMID 41483836 (2026, Toxicology letters)** — *[Paraphrased derived summary — non-Open-Access source.]* Noting global amphibian declines and the African clawed frog (Xenopus laevis) role as an OECD test species, this work built open-source quantitative structure–activity relationship (QSAR) models to predict acute developmental toxicity (12-hour LC50) for data-poor chemicals. It curated 1,978 historical entries (349 structures) from the US EPA ECOTOX and Ortiz-Santaliestra databases down to 359 entries covering 175 compounds, expressed as negative-log molar LC50, then split into training, test, and prediction sets; the excerpt is cut off before the model validation results. [21] > **PMID 41670719 (2026, Archives of environmental contamination and toxicology)** — *[Paraphrased derived summary — non-Open-Access source.]* Experiments on Northwestern Salamander (Ambystoma gracile) larvae showed copper toxicity depends strongly on water hardness: acute LC50 was 33.16 µg/L in soft water versus 1383 µg/L in moderately hard water, and the 35-day subchronic LC50 was 28.97 µg/L, with delayed development, lower survival, and reduced growth. Acute exposure raised metallothionein-1 (mt1) expression—a metal-detoxification response—but left thyroid-hormone receptor (thra, thrb), estrogen receptor (esr1α), and deiodinase (dio1) genes unchanged. The authors highlight species-specific copper sensitivity and note caudate amphibians are often missing from ecological risk assessments. [22] > **PMID 42146017 (2026, Frontiers in physiology)** — Physiological responses and adaptive mechanisms of amphibians and reptiles to multiple interacting environmental stressors: an integrative review. (opening): This integrative review synthesizes current knowledge on the physiological responses and adaptive mechanisms of amphibians and reptiles to multiple interacting environmental stressors, with particular emphasis on synergistic effects among temperature, hydric stress, disease, and pollution. Given the stronger empirical basis for amphibians in the existing literature, amphibian responses are covered in greater depth, while reptile-specific physiology, immunology, and emerging infectious diseases are explicitly addressed in dedicated sections throughout the review. Critical thermal tolerance analyses reveal that approximately 7.5% of amphibian species will exceed their physiological limits under a 4 °C warming scenario, with tropical lowland species already operating near their CTmax thresholds. Thermal plasticity is limited, with acclimation responses averaging only 0.13 °C increase in CTmax per 1 °C environmental warming-insufficient to track rapid climate change. Water balance regulation shows dramatic interspecific variation, with cutaneous resistance ranging from 0.05 s/cm in aquatic amphibians to >1000 s/cm in desert-adapted reptiles. Synergistic interactions between thermal and hydric stress significantly amplify vulnerability, particularly in dehydration scenarios that reduce critical thermal limits. Chemical pollutants, including heavy metals and pesticides, cause developmental abnormalities (535% increase in malformation frequency), immunosuppression, and endocrine disruption across multiple life stages. Emerging infectious diseases, particularly chytridiomycosis ( Batrachochytrium dendrobatidis and B. salamandrivorans ) and ranaviruses, drive mass mortality events globally, with co-infections exacerbating population declines. Climate change intensifies disease susceptibility through stress-mediated immunosuppression and altered pathogen dynamics. Adaptive capacity varies markedly among species. While amphibians exhibit strong phenological responses (2-4× greater than other taxa), genetic adaptation potential remains limited by narrow dispersal abilities and habitat fragmentation. Microhabitat buffering can reduce thermal extremes by several degrees but depends critically on habitat structural integrity. This review demonstrates that the pace of anthropogenic change challenges the adaptive capacity of most species, necessitating integrated conservation strategies including microhabitat preservation, climate corridor establishment, pollution mitigation, disease surveillance, and ex-situ conservation programs. *[CC BY — Open Access, verbatim with attribution.]* [23] > **PMID 40298996 (2025, Bulletin of environmental contamination and toxicology)** — *[Paraphrased derived summary — non-Open-Access source.]* A laboratory bioassay tested the pyrethroid insecticide lambda-cyhalothrin on tadpoles of the Neotropical frog Boana pulchella (Argentine Pampas) at 1.5 and 10 µg/L versus a control, measuring swimming speed via video tracking after 2 and 96 hours. No deaths occurred, but tail-flexion appeared in all exposed tadpoles (absent in controls) and swimming velocity was significantly reduced, more so at the higher concentration. The authors conclude that field-realistic lambda-cyhalothrin levels alter tadpole morphology and swimming, with likely consequences for competitive fitness and non-target amphibian communities. [24] > **PMID 40181708 (2025, Journal of morphology)** — Perichordal Vertebral Column Formation in Rana kobai. (opening): The vertebral column of anurans exhibits morphological diversity that is often used in phylogenetic studies. The family Ranidae is one of the ecologically most successful groups of anurans, with the genus Rana being distributed broadly in Eurasia. However, there are relatively sparse detailed studies on the development of the vertebral column in Rana species, and images of the entire axial skeleton have seldom been illustrated till date. Here, we provide an illustrated description on the development of the entire vertebral column in Rana kobai, a Japanese small frog from the Amami Islands. Our observation of double-stained skeletal specimens revealed that in R. kobai, the original atlas and the first dorsal are fused into one vertebra, and the ninth neural arch is fused with the tenth arch in half of the examined larvae. Anuran vertebral column development is classified into two modes, perichordal and epichordal. Rana species undergo the typical perichordal mode of centrum formation. Kemp and Hoyt (1969) described that centrum formation in R. pipiens starts from a saddle-shaped bone on the dorsal half of the notochord. Nevertheless, our detailed observations revealed that centrum ossification initially emerges at the base of the paired neural arches and then forms the saddle-shaped bone. In Xenopus, a species with epichordal centra, centrum formation starts from a pair of ovoid bone elements at the base of the neural arches. Overall, our results imply that centrum ossification starts from the base of neural arches in anurans, irrespective of whether it is perichordal or epichordal. Our observations also revealed the presence of the crescent-shaped cartilage domain in the intervertebral region in R. kobai. The location of the crescent-shaped domain in R. kobai is consistent with that of the intercentrum in Ichthyostega and several temnospondyls. Based on our observations, we propose a hypothesis on the difference between perichordal and epichordal modes in light of evolution. *[CC BY — Open Access, verbatim with attribution.]* [25] > **PMID 39855321 (2025, Environmental toxicology and pharmacology)** — *[Paraphrased derived summary — non-Open-Access source.]* Tadpoles of Boana faber were exposed for 168 hours to a glyphosate-based herbicide at 65, 260, and 520 µg/L. Body-condition biomarkers dropped significantly at the two higher concentrations; at the highest level superoxide dismutase activity rose while lipid-peroxidation levels were maintained, and carbonyl-protein reductions (with raised catalase) appeared at the lower concentrations. Glycogen fell across all exposed groups, indicating its use for energy production. The authors propose these body-condition markers as a non-invasive way to assess amphibian health. [26] > **PMID 41295741 (2025, Veterinary sciences)** — Hematology Reference Values for the Iberian Ribbed Newt (Pleurodeles waltl) Under Human Care. (opening): The Iberian ribbed newt ( Pleurodeles waltl ) is a salamander in the Salamandridae family. Endemic to the Iberian Peninsula and North Africa, it is not commonly found in zoological institutions or wildlife rescue centers. As in other species, routine blood analysis of amphibians under human care is highly recommended, forming an essential component of preventive medicine and effective clinical management. However, despite the great utility of hematological parameters for the diagnosis and prevention of diseases in amphibians, the lack of reliable reference values for many species severely limits their clinical use. The aim of this study is to establish preliminary reference values (RV) for the main hematological parameters in the Iberian ribbed newt. Blood samples were taken from healthy adult individuals ( n = 30), females ( n = 9) and males ( n = 21) maintained under controlled conditions in two zoological institutions. A complete hematological analysis was conducted, which included measurements of hematocrit, total erythrocyte and leukocyte counts, as well as a leukocyte differential. The reference intervals were established according to the guidelines provided by the American Society for Veterinary Clinical Pathology (ASVCP) for sample sizes between 20 and 40 individuals. No significant sex-related differences were detected in the hematological parameters analyzed. Despite the broad reference ranges obtained, these preliminary data provide an essential foundation for the clinical assessment and preventive medical management of P. waltl under human care. Expanding the dataset through collaboration with additional institutions will further refine and improve the accuracy and clinical utility of these reference values. *[CC BY — Open Access, verbatim with attribution.]* [27] > **PMID 41234787 (2025, Royal Society open science)** — Arid habitats intensify sexual conflict in invasive cane toads (Rhinella marina). (opening): Amplexus by male cane toads ( Rhinella marina ) impairs a female's mobility and may impose a risk of drowning. Near the arid-zone edge of the toads' Australian invasion, artificial ponds provide the only permanent open water. Cane toads must access water to hydrate every few nights, creating a potential for sexual conflict. Our field-based experiments show that a female toad that approaches one of these steep-sided dams encounters numerous reproductively active males, most of which are facing the shore. When amplexed by these males, she may find herself in deep water even close to the shore and is vulnerable to drowning. In trials with tethered females, toads amplexed in deep water could not hold their heads above the water's surface. Demographic effects of this sexual conflict are evident from population surveys: toad populations around dams are strongly male-biased whereas females are concentrated at mesic refuges around buildings that provide less dangerous conditions. Even around the same dam, female toads are often found on land whereas most males are found in the water. If sexual conflict around scarce waterbodies is lethal for female toads, we might reduce recruitment by allowing dense populations of male toads to persist. *[CC BY — Open Access, verbatim with attribution.]* [28] > **PMID 40274765 (2025, Nature communications)** — Structural basis for saxitoxin congener binding and neutralization by anuran saxiphilins. (opening): Dinoflagellates and cyanobacteria produce saxitoxin (STX) and ~50 congeners that disrupt bioelectrical signals by blocking voltage-gated sodium channels (Na V s). Consuming seafood carrying these toxins causes paralytic shellfish poisoning (PSP). Although Na V s and anuran STX binding proteins (saxiphilins, Sxphs) use convergent STX binding modes, the structural basis for STX congener recognition is unknown. Here, we show that American bullfrog (Rana catesbeiana) RcSxph and High Himalaya frog (Nanorana parkeri) NpSxph sequester STX congeners using a 'lock and key' mode shared with STX. Importantly, functional studies demonstrate that Sxph 'toxin sponges' reverse Na V block by multiple STX congeners and detect these toxins in a radioligand binding assay (RBA) used for environmental testing. Together, our study establishes how Sxphs sequester select neurotoxins and uncover STX congener-specific interactions distinct from Na V s. These findings expand understanding of toxin sponge action and provide a foundation for strategies to monitor and mitigate the harmful effects of STX congeners. *[CC BY — Open Access, verbatim with attribution.]* [29] ### Evidence cluster — Pet amphibian (anuran) nutrition (peer-reviewed, Europe PMC) > **PMID 42454479 (2026, Journal of morphology)** — *[Paraphrased derived summary — non-Open-Access source.]* A developmental study of the phytotelm-dwelling Brazilian toad Dendrophryniscus lauroi describes its premetamorphic embryos and tadpoles, noting features shared with pond-type bufonids (dark pigmentation, Type-B adhesive glands, labial tooth row 2/3, small size) plus heterochronic shifts—accelerated hind-limb development and delayed oral-morphology transformation. Some bufonids show mouthpart reduction and a short yolk-filled gut linked to absent active feeding, more pronounced in obligate endotrophic forms; D. lauroi can metamorphose with or without food. The authors frame phytotelm microhabitats as a model for ecomorphological evolution. [30] > **PMID 42152794 (2026, Journal of morphology)** — Amphibian Intestine Allometry. (opening): Across four large vertebrate groups-fish, reptiles, birds and mammals- intestine length has been shown to scale hyper-allometrically with body mass (BM), at an exponent higher than the geometric (isometric) expectation, 0.33. So far, amphibians have not been investigated in this respect. Combining original data from dissections and literature data, we evaluated the scaling of total intestine length with BM in the adult stages of 38 amphibian species (37 of which anurans). The BM range of investigated taxa was 2.2 to 113.5 g. When accounting for phylogeny, intestine length scaled with BM at an exponent with a 95% confidence interval of 0.39 to 0.53, corroborating the hyper-allometric scaling observed in other vertebrates. The hypothetical explanation is that larger animals, while requiring a proportionate intestinal absorptive surface to meet their metabolic demands, need to maintain short diffusion distances between the sites of digestive enzyme secretion/nutrient absorption and the digesta. This mechanism should result in hypo-allometric scaling of intestine diameter, with the hyper-allometric scaling of intestinal length ensuring the overall constancy of functional organ surface. *[CC BY — Open Access, verbatim with attribution.]* [31] > **PMID 41751121 (2026, Animals: an open access journal from MDPI)** — Effects of Two Different Dietary Calcium Concentrations on Bone Density and Skin Microbiome in Lemur Tree Frogs (Agalychnis lemur). (opening): The lemur tree frog ( Agalychnis lemur ), a critically endangered species, can benefit from ex situ conservation programs; however, managing amphibians under human care presents challenges, including the provision of appropriate nutrition. House crickets ( Acheta domesticus ), a common feeder insect, have an inverse calcium to phosphorus ratio (Ca:P; 0.15:1) and low calcium content ( Agalychnis spp. Moreover, no study has examined how diet impacts the gut-skin axis and skin microbiome of these frogs. This study examined how crickets gut-loaded with either a 1.3% or 8% calcium diet affected lemur tree frog bone density and skin microbiome. We hypothesized that frogs consuming the 8% calcium diet would exhibit significantly higher Hounsfield units (HU; bone density) over time, as measured by micro-computed tomography (mCT), and that dietary calcium concentration would have no effect on skin bacterial and fungi microbiomes. Eleven juvenile lemur tree frogs underwent mCT scans at baseline and 90 and 180 days. Total body volume of interest analysis showed a significant increase in HU in the 8% calcium group compared to the 1.3% group (F = 9.9, p = 0.01). There was no significant difference noted in the alpha or beta diversities for the bacterial and fungal microbiomes between dietary groups. This study provides the first evidence of dietary calcium's impact on bone density in lemur tree frogs, offering valuable insights for improving ex situ management of this species. *[CC BY — Open Access, verbatim with attribution.]* [32] > **PMID 41106716 (2025, Comparative biochemistry and physiology. Part A, Molecular & integrative physiology)** — *[Paraphrased derived summary — non-Open-Access source.]* An American toad (Anaxyrus americanus) study tested metabolic supplements to reactivate sperm motility after osmolality shifts from cryopreservation. Across treatments, bovine serum albumin (BSA, 0.1–0.4%) raised recovered total motility versus control at all concentrations (p < 0.05), and caffeine (1 mM) improved forward-progressive movement (p < 0.05); bicarbonate and lactate lowered both measures while pyruvate had no effect. The authors highlight BSA and caffeine for preserving motility in short-term-stored or cryopreserved sperm. [33] > **PMID 41212884 (2025, PloS one)** — Diet and chemical defenses of the Sonoran Desert toad. (opening): The Sonoran Desert toad (Incilius alvarius) is the only animal known to secrete the psychedelic compound 5-MeO-DMT as a chemical defense, but the source of 5-MeO-DMT in I. alvarius remains unknown. Some amphibians produce chemical defenses endogenously or through symbiotic interactions, while others acquire them from specialized diets. In this study we analyzed toxin gland secretions and diet profiles from wild I. alvarius and sympatric anurans from native and urban habitats around Tucson, Arizona to explore possible links between diet and 5-MeO-DMT production. All I. alvarius secreted high concentrations of 5-MeO-DMT, whereas other sympatric toads did not. The diet of I. alvarius was similar to that of sympatric anurans, indicating that I. alvarius does not exhibit relative dietary specialization. We found slight dietary differences between I. alvarius in native and urbanized habitats. Taken together, these lines of evidence suggest that diet is not directly linked to 5-MeO-DMT production and support the alternative hypotheses that I. alvarius synthesizes 5-MeO-DMT endogenously or via a microbial symbiont. *[CC BY — Open Access, verbatim with attribution.]* [34] ### Pet axolotl (Ambystoma mexicanum) — diet & nutrition — representative studies (Europe PMC) > PMID 40305450 — Movement ecology of captive-bred axolotls in restored and artificial wetlands: Conservation insights for amphibian reintroductions and translocations. (PloS one, 2025). (opening): Amphibians are among the most endangered vertebrates globally due to habitat loss, environmental degradation, and urban expansion. The axolotl (Ambystoma mexicanum), a critically e [35] ## References [1] https://animaldiversity.org/accounts/Ambystoma_mexicanum/ *grade B: T3 professional reference, verbatim (computed per docs/topic_grading_guide.md §4)* [2] https://www.merckvetmanual.com/all-other-pets *grade B: T3 professional reference, paraphrase (computed per docs/topic_grading_guide.md §4)* [3] https://www.merckvetmanual.com/exotic-and-laboratory-animals/amphibians/environment-and-husbandry-for-amphibians *grade B: T3 professional reference, paraphrase/verbatim (computed per docs/topic_grading_guide.md §4)* [4] https://www.merckvetmanual.com/exotic-and-laboratory-animals/amphibians *grade B: T3 professional reference, paraphrase (computed per docs/topic_grading_guide.md §4)* [5] https://www.merckvetmanual.com/ *grade B: T2 peer-reviewed/T3 professional reference, paraphrase (computed per docs/topic_grading_guide.md §4)* [6] https://pmc.ncbi.nlm.nih.gov/articles/PMC13282347/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [7] AAFCO — Dog / Cat / Specialty-Pet Food Nutrient Profiles (NRC for specialty pets) — https://www.aafco.org/ *grade A: T1 government/standard, verbatim (computed per docs/topic_grading_guide.md §4)* [8] https://pubmed.ncbi.nlm.nih.gov/42117820/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [9] https://pubmed.ncbi.nlm.nih.gov/42101880/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [10] https://pubmed.ncbi.nlm.nih.gov/40539017/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [11] https://pubmed.ncbi.nlm.nih.gov/40873727/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [12] https://pubmed.ncbi.nlm.nih.gov/38818027/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [13] https://pubmed.ncbi.nlm.nih.gov/38354202/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [14] https://pubmed.ncbi.nlm.nih.gov/39052625/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [15] https://pubmed.ncbi.nlm.nih.gov/41524647/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [16] https://pubmed.ncbi.nlm.nih.gov/42126746/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [17] https://pubmed.ncbi.nlm.nih.gov/42015311/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [18] https://pubmed.ncbi.nlm.nih.gov/42311595/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [19] https://pubmed.ncbi.nlm.nih.gov/41766740/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [20] https://pubmed.ncbi.nlm.nih.gov/42528927/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [21] https://pubmed.ncbi.nlm.nih.gov/41483836/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [22] https://pubmed.ncbi.nlm.nih.gov/41670719/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [23] https://pubmed.ncbi.nlm.nih.gov/42146017/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [24] https://pubmed.ncbi.nlm.nih.gov/40298996/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [25] https://pubmed.ncbi.nlm.nih.gov/40181708/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [26] https://pubmed.ncbi.nlm.nih.gov/39855321/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [27] https://pubmed.ncbi.nlm.nih.gov/41295741/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [28] https://pubmed.ncbi.nlm.nih.gov/41234787/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [29] https://pubmed.ncbi.nlm.nih.gov/40274765/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [30] https://pubmed.ncbi.nlm.nih.gov/42454479/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [31] https://pubmed.ncbi.nlm.nih.gov/42152794/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [32] https://pubmed.ncbi.nlm.nih.gov/41751121/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [33] https://pubmed.ncbi.nlm.nih.gov/41106716/ *grade B: T2 peer-reviewed, paraphrase (computed per docs/topic_grading_guide.md §4)* [34] https://pubmed.ncbi.nlm.nih.gov/41212884/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* [35] https://pubmed.ncbi.nlm.nih.gov/40305450/ *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)* ## Supplement Data Roadmap *Known gaps in this manual, machine-checked against the published text on every build; an item appears only while the gap is still real.* - **Regulations & Legality depth**: only 1 verified legality line(s) so far — coverage is still being collected; consult your local authority before relying on this section. - **Root-domain reference(s)**: https://www.merckvetmanual.com/, https://www.aafco.org/ — these point to a source home page rather than the exact page; being fixed.