Poison Frog Research Articles

Behavioural consistency across metamorphosis in a neotropical poison frog.

Animals often show consistency in their behavioural repertoire across time and/or contexts that differs from other individuals of the same population, i.e. animal personality. We currently have quite an incomplete understanding of the factors that lead to behavioural traits remaining stable - or becoming decoupled - over an animal's lifetime. In this study, we investigated the role of metamorphosis in the development of animal personality in a Neotropical poison frog, a species that undergoes drastic morphological and ecological changes during its development. We used lab-reared individuals of the brilliant-thighed poison frog Allobates femoralis to assess if consistent individual differences are already present at the tadpole stage, and if these differences are maintained throughout metamorphosis. We found evidence for two personality traits, exploration and boldness, already present in A. femoralis tadpoles. Despite the drastic changes in morphology, physiology, and habitat in the transition from tadpoles to metamorphs, personality traits persisted throughout metamorphosis, suggesting a physiological and/or genetic basis for the measured behavioural traits. We also found that exploration and boldness related behaviours were correlated with growth speed. Very bold and explorative individuals took fewer days until metamorphosis compared to very shy and non-explorative ones, which is in line with the concept of a Pace-of-Life Syndrome. These findings provide important insights into the proximate mechanisms that generate personality in species with complex life cycles.

An empty stomach is not a good adviser: avoiding toxic Cyanobacteria can compromise tadpole antipredator defenses

Abstract Eutrophication events resulting from increased primary production are becoming common under changing environmental conditions that include habitat degradation and disturbance of food webs. They cause several detrimental ecological consequences including the intoxication of animals that ingest toxic Cyanobacteria. We tested whether the tadpole of an anthropophilic frog (Scinax longilineus) would avoid feeding on a potentially toxic Cyanobacteria using Raphidiopsis raciborskii as a model. We maintained tadpoles in water collected from a natural monospecific growth of R. raciborskii at the original concentration (100%) and concentrations of 0, 25, 50 and 75% of the original sample diluted in rested tap water. We evaluated the amount of R. raciborskii ingested by the tadpoles and conducted behavioral tests by exposing tadpoles to an aversive stimulus and quantifying their escape response. Tadpoles ate the least R. raciborskii the highest the concentration of this Cyanobacteria was in the water. Tadpoles exposed to 50 and 75% of the original concentration of the R. raciborskii sample had a reduction of time spent escaping, what is likely to compromise their ability to escape a real predator attack. Tadpoles at the highest concentration (100%) did not show significant changes in their escape performance, however they practically stopped feeding, what would not be a solution in the long term (i.e., duration of a real bloom). We conclude that tadpoles of S. longilineus can recognize the presence of R. raciborskii and avoid its ingestion, with potential sub-lethal effects represented by a reduced ability to escape predators.

Tratamento da intoxicação por zolpidem com flumazenil em um gato

This report aims to describe the case of a cat intoxicated with zolpidem that was treated with flumazenil. Flumazenil is an imidazodiazepine that effectively reverses the central effects of benzodiazepines. In humans, it is used to treat zolpidem poisoning. Zolpidem is a sedative hypnotic agent, non-benzodiazepine, that is used to treat patients with insomnia. A 2-year-old Bengal cat weighing 2.5 kg showed signs of ataxia, incoordination and diarrhea after accidental ingestion of 10 mg zolpidem (Stilnox®). The cat was administered with 0.1 mg/kg of flumazenil intravenously, and after 20 minutes all clinical signs disappeared. To our knowledge, this is the first report of the use of flumazenil for the treatment of zolpidem poisoning in cats. Discussion regarding the treatment of zolpidem poisoning is necessary owing to the increased prescription of this drug in humans and, consequently, to a greater possibility of accidental poisoning in domestic animals.

Selection on Visual Opsin Genes in Diurnal Neotropical Frogs and Loss of the SWS2 Opsin in Poison Frogs.

Amphibians are ideal for studying visual system evolution because their biphasic (aquatic and terrestrial) life history and ecological diversity expose them to a broad range of visual conditions. Here, we evaluate signatures of selection on visual opsin genes across Neotropical anurans and focus on three diurnal clades that are well-known for the concurrence of conspicuous colors and chemical defense (i.e., aposematism): poison frogs (Dendrobatidae), Harlequin toads (Bufonidae: Atelopus), and pumpkin toadlets (Brachycephalidae: Brachycephalus). We found evidence of positive selection on 44 amino acid sites in LWS, SWS1, SWS2, and RH1 opsin genes, of which one in LWS and two in RH1 have been previously identified as spectral tuning sites in other vertebrates. Given that anurans have mostly nocturnal habits, the patterns of selection revealed new sites that might be important in spectral tuning for frogs, potentially for adaptation to diurnal habits and for color-based intraspecific communication. Furthermore, we provide evidence that SWS2, normally expressed in rod cells in frogs and some salamanders, has likely been lost in the ancestor of Dendrobatidae, suggesting that under low-light levels, dendrobatids have inferior wavelength discrimination compared to other frogs. This loss might follow the origin of diurnal activity in dendrobatids and could have implications for their behavior. Our analyses show that assessments of opsin diversification in across taxa could expand our understanding of the role of sensory system evolution in ecological adaptation.

Poisonous substances and geographical distribution of poisoning in hospitalized children based on data from 25 hospitals in China from 2016 to 2020

Objective: To investigate the poisonous substances and geographical distribution of poisoning in children in China. Methods: A cross-sectional study. The clinical data of 8 385 hospitalized children from January 2016 to December 2020 were extracted from the FUTang Updating Medical Records database. These children aged 0 to 18 years and were admitted due to poisoning. They were grouped according to age (newborns and infants, toddlers, preschoolers, school-age children, adolescents), place of residence (Northeast China, North China, Central China, East China, South China, Southwest China, Northwest China), and mode of discharge (discharge under medical advice, transfer to another hospital under medical advice, discharge without medical advice, death, other). The poisonous substance and causes of poisoning in different groups were analyzed. Results: Among these 8 385 children, 4 734 (56.5%) were male and 3 651 (43.5%) female, with a male-to-female ratio of 1.3∶1. The age was 3 (2, 7) years. The prevalence of poisoning was 51.8% (4 343/8 385) in toddlers, 16.5% (1 380/8 385) in adolescents, 14.8% (1 242/8 385) in preschoolers, 14.4% (1 206/8 385) in school-age children, and 2.5% (214/8 385) in newborns and infants. Drug poisoning accounted for 43.5% (3 649/8 385) and pesticide accounted for 26.8% (2 249/8 385). Drug poisoning was more common in adolescents (684/1 380, 49.6%) and toddlers (2 041/4 343, 47.0%); non-drug poisoning was more common in school-age children (891/1 206, 73.9%), of which carbon monoxide was mainly in newborns and infants (41/214, 19.2%) and food poisoning in children of school age (241/1 206, 20.0%). Regarding regional characteristics, drug poisoning was more frequent in South China (188/246, 64.2%) and non-drug poisoning was more frequent in Southwest China (815/1 123, 72.5%). For drugs, anti-epileptic drugs, sedative-hypnotic drugs and anti-Parkinson's disease drugs had a higher proportion of poisoning in North China (138/1 034, 13.0%) than that in other regions. For non-drug poisoning, pesticides (375/1 123, 33.3%), food poisoning (209/1 123, 18.6%) and contact with poisonous animals (86/1 123, 7.7%) were more common in Southwest China than in other regions; carbon monoxide poisoning was more common in North China (81/1 034, 7.6%) and Northwest China (65/1 064, 6.3%). In Central China, poisoning happened more in toddlers (792/1 295, 61.2%) and less in adolescents (115/1 295, 8.8%) than in other regions. Regarding different age groups, poisoning in adolescent happened more in Northeast China (121/457, 26.5%), North China (240/1 034, 23.2%), and Northwest China (245/1 064, 23.0%). The rate of discharge under medical advice, discharge without medical advice, and mortality rate within the 5 years were 77.0% (6 458/8 385), 20.8% (1 743/8 385), 0.5% (40/8 385), respectively. Conclusions: Poisoning is more common in male and toddlers. Poisonous substances show a regional characteristic and vary in different age groups, with drugs and insecticides as the most common substances.

The molecular basis and evolution of toxin resistance in poison frogs

The molecular basis and evolution of toxin resistance in poison frogs

The ability to sequester the alkaloid epibatidine is widespread among dendrobatid poison frogs

The ability to sequester the alkaloid epibatidine is widespread among dendrobatid poison frogs

Effect of HYD Drugs on Hemolytic Anemia Induced by Phenylhydrazine Hydrochloride

In conclusion, the conducted experiments showed that the histostructure of the vital internal organs of rats in the control and experimental groups was almost the same. At the same time, drug-related histomorphological changes in their histostructure were not noted. It should be noted separately that the study of the histostructure of the liver and kidney from the parenchymatous organs of the animals that received the studied tincture showed that some morphological signs indicating their functional activity appeared. Therefore, long-term administration of the antianemic compound - DOY tincture to the body does not cause chronic poisoning in animals and any negative reactions in the histostructure of vital internal organs and biochemical analyzes of peripheral blood.

Estimation of acute oral toxicity of the drug "Mastigard®"

The parameters of acute oral toxicity of Mastigard® are presented. The drug was introduced intragastrically to rats at a dose of 2000 mg/kg. During the study, the tested dose did not cause signs of intoxication and death of animals. Physiological parameters of rats remained within the species norm. Also no changes in the behavior of animals were noted, the reaction to tactile, pain, sound and light irritants was adequate. Autopsy of animals at the end of observation did not reveal pathological and anatomical changes in internal organs and tissues. Regular control of body weight of rats testified to uniform weight gain of all experimental animals during 14 days of observation, no body weight loss was observed during all periods of weighing. Thus, the LD50 of Mastigard® is more than 2000 mg/kg. Mastigard® belongs to the 5th class of toxicity according to the GHS and the 4th class of danger (substances of little danger) according to GOST 12.1.007-76.

How to move and when to escape: quantifying intraspecific exploratory and anti-predator behavior in an aposematic poison frog

How to move and when to escape: quantifying intraspecific exploratory and anti-predator behavior in an aposematic poison frog

Transcriptomic analyses during development reveal mechanisms of integument structuring and color production

Skin coloration and patterning play a key role in animal survival and reproduction. As a result, color phenotypes have generated intense research interest. In aposematic species, color phenotypes can be important in avoiding predation and in mate choice. However, we still know little about the underlying genetic mechanisms of color production, particularly outside of a few model organisms. Here we seek to understand the genetic mechanisms underlying the production of different colors and how these undergo shifting expression patterns throughout development. To answer this, we examine gene expression of two different color patches(yellow and green) in a developmental time series from young tadpoles through adults in the poison frog Oophaga pumilio. We identified six genes that were differentially expressed between color patches in every developmental stage (casq1, hand2, myh8, prva, tbx3, and zic1). Of these, hand2, myh8, tbx3, and zic1 have either been identified or implicated as important in coloration in other taxa. Casq1 and prva buffer Ca2+ and are a Ca2+ transporter, respectively, and may play a role in preventing autotoxicity to pumiliotoxins, which inhibit Ca2+-ATPase activity. We identify further candidate genes (e.g., adh, aldh1a2, asip, lef1, mc1r, tyr, tyrp1, xdh), and identify a suite of hub genes that likely play a key role in integumental reorganization during development (e.g., collagen type I–IV genes, lysyl oxidases) which may also affect coloration via structural organization of chromatophores that contribute to color and pattern. Overall, we identify the putative role of a suite of candidate genes in the production of different color types in a polytypic, aposematic species.

Personality traits differentially affect components of reproductive success in a Neotropical poison frog.

Individual reproductive success has several components, including the acquisition of mating partners, offspring production, and offspring survival until adulthood. While the effects of certain personality traits-such as boldness or aggressiveness-on single components of reproductive success are well studied, we know little about the composite and multifaceted effects behavioural traits can have on all the aspects of reproductive success. Behavioural traits positively linked to one component of reproductive success might not be beneficial for other components, and these effects may differ between sexes. We investigated the influence of boldness, aggressiveness, and exploration on the number of mating partners, mating events, and offspring surviving until adulthood in males and females of the Neotropical poison frog Allobates femoralis. Behavioural traits had different-even opposite-effects on distinct components of reproductive success in both males and females. For example, males who displayed high levels of aggressiveness and exploration (or low levels of aggressiveness and exploration) managed to attract high number of mating partners, while males with low levels of boldness, low levels of aggressiveness, and high levels of exploration had the most offspring surviving until adulthood. Our results therefore suggest correlational selection favouring particular combinations of behavioural traits.

Odor cues rather than personality affect tadpole deposition in a neotropical poison frog.

Animals constantly need to evaluate available external and internal information to make appropriate decisions. Identifying, assessing, and acting on relevant cues in contexts such as mate choice, intra-sexual competition, and parental care is particularly important for optimizing individual reproductive success. Several factors can influence decision-making, such as external environmental cues and the animal's own internal state, yet, we have limited knowledge on how animals integrate available information. Here, we used an entire island population (57 males, 53 females, and 1,109 tadpoles) of the neotropical brilliant-thighed poison frog Allobates femoralis to investigate how 2 factors (olfactory cues and personality traits) influence the ability of males to find and use new resources for tadpole deposition. We experimentally manipulated the location of tadpole deposition sites and their associated olfactory cues, and repeatedly measured exploration and boldness in adult males. We further reconstructed tadpole deposition choices via inferred parent-offspring relationships of adult frogs and tadpoles deposited in our experimental pools using molecular parentage analysis. We found that the discovery and use of new rearing sites were heavily influenced by olfactory cues; however, we did not find an effect of the measured behavioral traits on resource discovery and use. We conclude that in highly dynamic environments such as tropical rainforests, reliable external cues likely take priority over personality traits, helping individuals to discover and make use of reproductive resources.

Adult poison frogs can capture and consume aquatic tadpoles

Adult poison frogs can capture and consume aquatic tadpoles

Mother strawberry poison frogs might supplement nutritive eggs with secretory provisioning

Mother strawberry poison frogs might supplement nutritive eggs with secretory provisioning

Orientation by environmental geometry and feature cues in the green and black poison frog (Dendrobates auratus).

The ability to use environmental geometry when orienting in space reflects an animal's ability to use a global, allocentric framework. Therefore, understanding when and how animal's use geometry relative to other types of cues in the environment has interested comparative cognition researchers for decades. Yet, only two amphibians have been tested to date. We trained the poison frog Dendrobates auratus to find goal shelters in a rectangular arena, in the presence and absence of a feature cue, and assessed the relative influence of the two types of cues using probe trials. We chose D. auratus because the species has complex interactions with their physical and social environments, including parental care that requires navigating to and from distant locations. We found that, like many vertebrates, D. auratus are capable of using geometric information to relocate goals. In addition, the frogs preferentially used the more reliable feature cue when the location of the feature conflicted with the geometry of the arena. The frogs were equally successful at using the feature cue when it was proximal or distal to the goal shelter, consistent with prior studies that found that D. auratus can use distal cues in a flexible manner. Our results provide further evidence that amphibians can use environmental geometry during orientation. Future studies that examine when and how amphibians use geometry relative to other types of cues will contribute to a more complete picture of spatial cognition in this important, yet understudied, group.

Hypoglycin A in Acer genus plants

Hypoglycin A (HGA) is an amino acid occuring in the Sapindaceae family. Ingestion of certain Acer genus plants belonging to this family has been connected with atypical myopathy (AM) or seasonal pasture myopathy (SPM). To date, all cases of AM/SPM have been associated with sycamore (Acer pseudoplatanus) and boxelder maple (Acer negundo). The aim of this work was to determine and compare HGA in sycamore, boxelder and silver maple (Acer saccharinum), the trees known for HGA content, whose occurence is quite common in the Czech Republic. In sycamore and boxelder maple the effect of location, weather condition and sampling season was evaluated.The other aim was screening for presence of HGA in 12 other species of Acer genus which are grown as ornamental trees in Europe. The determination of HGA was conducted using ultra – high performance liquid chromatography – tandem mass spectrometry (LC/MS). HGA was detected in all samples of sycamore, boxelder and silver maple except for eight leave samples of boxelder maple. In the case of sycamore maple, the highest concentrations of HGA (median) were found in seedlings (770 mg/kg) followed by samaras (130 mg/kg) and by leaves (48 mg/kg) and inflorescences (24 mg/kg). In boxelder maple, significantly higher concentrations of HGA (median) were found in seedlings (550 mg/kg) compared with samaras (45 mg/kg), leaves (14 mg/kg) and inflorescences (24 mg/kg). According to the results the seedlings could pose a significant risk of poisoning, although other factors such as accessibility and palatability of other parts, especially samaras, should be considered. No significant differences of HGA concentrations in silver maple (56 mg/kg) were found between samaras, leaves and inflorescences. HGA was also identified in sugar maple (Acer saccharum), Japanese maple (Acer palmatum), trident maple (Acer buergerianum), paperbark maple (Acer griseum) and Himalayan maple (Acer oblongum). Although silver maple and other ornamental maples have not been reported to cause AM/SPM, the possibility of intoxication in animals can not be excluded.

Tissue-specific in vivo transformation of plasmid DNA in Neotropical tadpoles using electroporation.

Electroporation is an increasingly common technique used for exogenous gene expression in live animals, but protocols are largely limited to traditional laboratory organisms. The goal of this protocol is to test in vivo electroporation techniques in a diverse array of tadpole species. We explore electroporation efficiency in tissue-specific cells of five species from across three families of tropical frogs: poison frogs (Dendrobatidae), cryptic forest/poison frogs (Aromobatidae), and glassfrogs (Centrolenidae). These species are well known for their diverse social behaviors and intriguing physiologies that coordinate chemical defenses, aposematism, and/or tissue transparency. Specifically, we examine the effects of electrical pulse and injection parameters on species- and tissue-specific transfection of plasmid DNA in tadpoles. After electroporation of a plasmid encoding green fluorescent protein (GFP), we found strong GFP fluorescence within brain and muscle cells that increased with the amount of DNA injected and electrical pulse number. We discuss species-related challenges, troubleshooting, and outline ideas for improvement. Extending in vivo electroporation to non-model amphibian species could provide new opportunities for exploring topics in genetics, behavior, and organismal biology.

Variation in the advertisement call of the poison frog Andinobates bombetes relates to geographic distance between populations, but not to divergence in warning coloration

ABSTRACT Studying intraspecific geographic variation in communication signals represents a good approach to understand the evolution of species diversification in animals. The poison frog Andinobates bombetes (Dendrobatidae) exhibits intraspecific geographic variation in the spectral traits of its advertisement call. However, it is still unknown whether there is concomitant variation in temporal call traits, and whether call variation is somehow linked to differences in warning coloration (red and yellow morphs). We analyzed spectral and temporal traits of the advertisement calls recorded from 100 males belonging to twelve populations of A. bombetes: nine bearing the red coloration, and three bearing the yellow one. After controlling for eventual effects of temperature and body size of males in call traits, we found geographic variation in both spectral and temporal call traits, yet such variation was unrelated to differences in warning coloration between populations. Previous research indicated that geographic variation in the spectral properties of this species advertisement call can be explained by concomitant differences in the acoustic abiotic environment. Nonetheless, a positive relationship between geographic distance and call divergence also supports the role of genetic drift in the evolution of acoustic signaling of A. bombetes.

Geographic Variability, Seasonality, and Increase in ASPCA Animal Poison Control Center Harmful Blue-Green Algae Calls-United States and Canada, 2010-2022.

Harmful cyanobacteria (blue-green algae) exposures can cause illness or death in humans and animals. We characterized American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Poison Control Center (APCC) harmful blue-green algae (HBGA) call data, compared it to a measure of harmful algal bloom public awareness, and considered its suitability as a public health information source. ASPCA APCC dog and cat "HBGA exposure" calls made 1 January 2010-31 December 2022 were included. We calculated annual HBGA call percentages and described calls (species, month, origin, exposure route). We characterized public awareness by quantifying Nexis Uni® (LexisNexis Academic; New York, NY, USA)-indexed news publications (2010-2022) pertaining to "harmful algal bloom(s)". Call percentage increased annually, from 0.005% (2010) to 0.070% (2022). Of 999 HBGA calls, 99.4% (n = 993) were dog exposures. Over 65% (n = 655) of calls were made July-September, largely from the New England (n = 154 (15.4%)) and Pacific (n = 129 (12.9.%)) geographic divisions. Oral and dermal exposures predominated (n = 956 (95.7%)). Harmful algal bloom news publications increased overall, peaking in 2019 (n = 1834). Higher call volumes in summer and in the New England and Pacific geographic divisions drove HBGA call increases; public awareness might have contributed. Dogs and humans have similar exposure routes. ASPCA APCC HBGA call data could serve as a public health information source.