Ventral Color Pattern Research Articles

New specimens of Helicops boitata (Serpentes: Dipsadidae: Hydropsini), with data on morphological variation and behavior

We report data on morphological variation and behavior of the recently described watersnake Helicops boitata, previously known strictly from the holotype. Our data come from five new specimens fortuitously found in a private area near the type locality, in the Brazilian Pantanal wetlands. The expanded sample revealed polymorphism in at least two scalation features previously assumed as diagnostic of the species (i.e., undivided condition of the cloacal plate and nasal scales) and confirmed the uniqueness of the ventral color pattern, as well as the divided condition of the foremost ventral shields. In addition, three individuals collected alive also exhibited the same harmless behavior reported to the holotype, a rather unusual feature among snakes of the genus Helicops. Other new behavioral observations include mostly nocturnal activity (in contrast with the previous data) and the ability to dig galleries in the soft substrate when attempting to escape. The finding of five individuals very close to each other suggest aggregations in habitats prone to retain humidity in the dry season of the Pantanal. Low abundance rates and possible habitat restrictions might render Helicops boitata particularly susceptible to seasonal fire episodes that consume large extensions of the wetlands, including temporarily dry flooding fields in which aquatic reptiles find refuge during the seasonal droughts.

How to find a wolverine: Factors affecting detection at wolverine (Gulo gulo) bait stations in western Canada

AbstractHigh individual detection success enables precise estimates of density and the ability to monitor trends in abundance for wolverine and other low‐density species, information that is critical for the implementation and assessment of conservation measures. We evaluated a dataset that included six different wolverine capture–recapture studies over a large gradient in wolverine (Gulo gulo) density to provide recommendations for increasing detection. We examined factors related to bait station components, habitat, and seasonal timing. Accounting for variation in wolverine density and trap duration, our results suggest that bait stations setups having a run pole, frame, and camera to photograph unique ventral color patterns, in addition to hair snag devices, identify more individual wolverine than those without. The presence of snow is a habitat feature that also increases individual detection. Female detection rates were lower than male detection rates at the onset of the reproductive denning season in late February and early March compared with January and early February. We found latency to detection was independent of wolverine density, but greater in areas with human influence. Relatively high rates of genotyping success (55%) were predicted by even a single guard hair left at bait stations, while underfur required ~15 hairs for similar success. Longer sampling intervals reduced genotyping success in spring, more so for underfur than guard hair. Hair samples acquired from barbwire were of higher quality than those from either alligator clips or gun brushes. To improve individual detection for wolverine inventory and monitoring, we recommend deploying run pole setups in areas with low human disturbance that will retain snow into late spring. Extending the winter trapping effort into April and May could increase the chances of detecting denning females. Latency to detection suggests that traps should be active for more than a month, especially in human‐influenced areas, but genotyping success suggests that traps should also be cleared of hair samples at smaller intervals of a month or less, during late winter/spring.

A New Miniature Species of Arthroleptis (Anura: Arthroleptidae) from Nyungwe National Park, Rwanda

A new, very small-sized species of Arthroleptis is described from western Rwanda. The new species occurs locally endemic in Nyungwe Forest and Cyamudongo Forest, where it inhabits the leaf litter of montane forests between 1800 and 2200 m a.s.l. It differs from all other members of the genus by a unique combination of morphological characters, including size (SVL of adult males 16.0–16.5 mm), skin texture, length of hindlimbs, and ventral colour pattern; by characteristics of its advertisement call that consists of a single note lasting 17.4 ± 6.4 [11–32] ms and has a dominant frequency of 5861 ± 188 [5531–6029] Hz; and also in the sequence of the 16S rRNA gene that differs from available homologous sequences of other species of the genus by an uncorrected p-distance of at least 4.6%. Details of the natural history as well as two additional call types are described.

Different Traits, Different Evolutionary Pathways: Insights from Salamandrina (Amphibia, Caudata).

Species delimitation is often based on a single or very few genetic or phenetic traits, something which leads to misinterpretations and often does not provide information about evolutionary processes. Here, we investigated the diversity pattern of multiple phenetic traits of the two extant species of Salamandrina, a genus split only after molecular traits had been studied but the two species of which are phenetically very similar. The phenetic traits we studied are size, external body shape and head colour pattern, in a model comparison framework using non-linear mixed models and unsupervised and supervised clustering. Overall, we found high levels of intra-specific variability for body size and shape, depending on population belonging and habitat, while differences between species were generally lower. The habitat the salamanders dwell in also seems important for colour pattern. Basing on our findings, from the methodological point of view, we suggest (i) to take into account the variability at population level when testing for higher level variability, and (ii) a semi-supervised learning approach to high dimensional data. We also showed that different phenotypic traits of the same organism could result from different evolutionary routes. Local adaptation is likely responsible for body size and shape variability, with selective pressures more similar across species than within them. Head colour pattern also depends on habitat, differently from ventral colour pattern (not studied in this paper) which likely evolved under genetic drift.

A new species of Andean golden poison frog (Andinobates, Dendrobatidae) from the Eastern Andes of Colombia.

A new species of Andinobates (Dendrobatidae) is described from the East Andes of Colombia, just 37 km away from the Colombian capital, Bogot. Andinobates supata sp. nov., represents the second known species of yellow Andinobates, and can be distinguished from the other, Andinobates tolimensis, by an unique combination of ventral and dorsal color patterns. Our phylogenetic analyses, based on ≈ 1120 bp from two mitochondrial markers (16S rRNA and cytochrome b) showed that this new taxon is sister to a clade formed by A. cassidyhornae, A. bombetes, A. opisthomelas, A. tolimensis and A. virolinensis. The new species appears to be restricted to a handful of small forest fragments (10 ha) distributed in no more than 5 km2, between 18002000 m elevation, where the human activity is high. In addition, more than 90% of the original forest has been logged at the type locality, and its watersheds receive considerable agrochemical discharges. Altogether, the evidence suggests that this new species should be listed as Critically Endangered and should receive immediate attention regarding basic research and urgent conservation measures.

Can ventral pattern be used for individual recognition of the vulnerable Pyrenean brook newt (Calotriton asper)?

Individual recognition of animal species is a prerequisite for capture-mark-recapture (CMR) studies. For amphibians, photoidentification of body pattern is a non-invasive and less expensive alternative than classical marking methods (e.g. passive integrated transponder). However, photo-identification is effective only if the patterns are (i) sufficiently variable between individuals, and (ii) stable over time. This method also depends on the observer’s judgment. In the present study, we assessed the effectiveness of an automatic algorithm (AmphIdent) to recognise ventral colour patterns of the Pyrenean brook newt (Calotrion asper), endemic to the Pyrenees Mountains of France. To assess the performance of the tested method, 113 individuals from two different streams were marked with passive integrated transponders (PIT-tags). We used false rejection rate (FRR), false acceptance rate (FAR) and true acceptance rate (TAR) as metrics to evaluate performances of photoidentification. Mean FRR was 7.3 %, FAR was 5.2 %, and TAR was 92 % across both streams, both sexes and all the observers. FAR was significantly different between sexes, while FRR and TAR were significantly influenced by the interaction between the sex and the stream. Despite these differences, our error rates are among the lowest values found in the literature for both amphibian and non-amphibian computer-assisted photo-identification. We found that poor-quality reference pictures could lead to an increasing difficulty to achieve a correct match when time since first capture rose. Consequently, individual photo-identification using AmphIdent software is a reliable tool to aid in the monitoring the Pyrenean brook newts, provided that pictures are taken with care, reference images are regularly updated and observers are properly trained to use the software and interpret images.

Increasing knowledge of the denizens of saline environments through integrative taxonomy: new Argentinian endemic taxa of Liolaemus (Iguania: Liolaemidae) and their evolutionary relationships

The known diversity of the genus Liolaemus continues to increase, principally due to its great degree of endemism, the increasing number of researchers working on it, and advances in the taxonomic and phylogenetic knowledge of the genus. This diversity positions Liolaemus as the second most species-rich tetrapod genus. The present work adds to evidence for the great diversity of Liolaemus through the description of two new species, endemic to saline environments in the Argentinian Puna. Both species are members of the Liolaemus montanus group within the subgenus Eulaemus. To determine the taxonomic status of these lizards, we used integrative taxonomy as a tool, incorporating phylogenetic, morphological, and molecular genetic evidence, as well as the anatomy of hemipenes, statistical morphological analysis, and ecological characteristics. Our analyses supported the conclusion that both sampled populations of lizards are species new to science. One of these is found along the margins of the Antofalla salt flats in the Catamarca Province and the Hombre Muerto salt flats in the Salta Province. The other new species inhabits saline habitats vegetated by Lycium humile, principally between the salt crusts of the Antofalla salt flats. Both species are small to medium sized and can be distinguished from all other species of the L. montanus group by unique combinations of morphological characters, primarily pholidosis and dorsal and ventral colour patterns. urn:lsid:zoobank.org:act:29B39613-3298-4B43-A13A-9F950051BD04 urn:lsid:zoobank.org:act:A97A5AA8-7295-4882-9809-CEFAD72E7202

Ontogenetic changes in the ventral colouration of post metamorphic Elachistocleis haroi Pereyra, Akmentins, Laufer, Vaira, 2013 (Anura: Microhylidae)

Abstract Ontogenetic colour change (OCC) is defined as the progressive and non-reversible process of changes in colouration of organisms associated with their development. Among the many vertebrate groups, amphibians are particularly impressive for their strikingly wide variety of colours, colour patterns, and signals, whose evolutionary and ecological significance have been poorly studied. Elachistocleis comprises 18 species currently separated into two main groups based on their ventral colour pattern: one immaculate and the other with specks and/or colour patches. Elachistocleis haroi is a small-sized species within the immaculate venter group, distributed in the Yungas and Dry Chaco ecoregions from which little information is known. In a comprehensive sampling of post-metamorphic individuals of E. haroi at different stages of development we identified a significant variation in ventral colour pattern, which could denote a progressive filling of yellow colour according to an ontogenetic pattern. To test this hypothesis, we analysed 39 post-metamorphic individuals of E. haroi at different stages of development with imaging procedures. We found that yellow spots and their intensity are significantly related to snout-vent length, as major expansion of colour on the sides, gular region and male chest, as almost no development on the belly. We briefly discuss our findings in relation to sexual display and predation avoidance. To our knowledge, this is the first analysis of post-metamorphic OCC in ventral colouration in the genus Elachistocleis.

A taxonomic revision of the south-eastern dragon lizards of the Smaug warreni (Boulenger) species complex in southern Africa, with the description of a new species (Squamata: Cordylidae).

A recent multilocus molecular phylogeny of the large dragon lizards of the genus Smaug Stanley et al. (2011) recovered a south-eastern clade of two relatively lightly-armoured, geographically-proximate species (Smaug warreni (Boulenger, 1908) and S. barbertonensis (Van Dam, 1921)). Unexpectedly, S. barbertonensis was found to be paraphyletic, with individuals sampled from northern Eswatini (formerly Swaziland) being more closely related to S. warreni than to S. barbertonensis from the type locality of Barberton in Mpumalanga Province, South Africa. Examination of voucher specimens used for the molecular analysis, as well as most other available museum material of the three lineages, indicated that the ‘Eswatini’ lineage—including populations in a small area on the northern Eswatini–Mpumalanga border, and northern KwaZulu–Natal Province in South Africa—was readily distinguishable from S. barbertonensis sensu stricto (and S. warreni) by its unique dorsal, lateral and ventral colour patterns. In order to further assess the taxonomic status of the three populations, a detailed morphological analysis was conducted. Multivariate analyses of scale counts and body dimensions indicated that the ‘Eswatini’ lineage and S. warreni were most similar. In particular, S. barbertonensis differed from the other two lineages by its generally lower numbers of transverse rows of dorsal scales, and a relatively wider head. High resolution Computed Tomography also revealed differences in cranial osteology between specimens from the three lineages. The ‘Eswatini’ lineage is described here as a new species, Smaug swazicus sp. nov., representing the ninth known species of dragon lizard. The new species appears to be near-endemic to Eswatini, with about 90% of its range located there. Our study indicates that S. barbertonensis sensu stricto is therefore a South African endemic restricted to an altitudinal band of about 300 m in the Barberton–Nelspruit–Khandizwe area of eastern Mpumalanga Province, while S. warreni is endemic to the narrow Lebombo Mountain range of South Africa, Eswatini and Mozambique. We present a detailed distribution map for the three species, and a revised diagnostic key to the genus Smaug.

Use of Space and Its Relationship with Sex, Body Size, and Color Polymorphism in Liolaemus xanthoviridis (Iguania: Liolaemini) in Patagonia

The local spatial distribution of individual animals is often described in terms of home range (HR), whereas territory traditionally refers to an area defended for exclusive use. The size of the HR is considered an important indicator of the behavioral characteristics of an animal, and it can be influenced by factors such as sex, body size, population density, and social behavior. In polymorphic species, morphs may differ in space use, and they may be characterized by different reproductive strategies. The aim of this study is to quantify space use in a population of the lizard Liolaemus xanthoviridis (Iguania: Liolaemini) and its relationship with body size, sex, and color polymorphism. At a single locality in Argentina (Bahía Isla Escondida, Chubut), over four summer seasons (2012–2015) we marked 156 lizards and recorded body measurements, sex, dorsal and ventral color patterns, and the spatial location of each individual. Our results showed that HR size differed significantly between sexes and was significantly associated with body sizes in males, but not with dorsal coloration and ventral melanism. Moreover, males of L. xanthoviridis have a high percentage of overlap in their HRs. The absence of a relationship between HR size and dorsal coloration or ventral melanism suggests the absence of multiple reproductive strategies within each sex. Because females of L. xanthoviridis seem to be territorial, but not males, we propose that they may be interacting in a system of dominance hierarchies, a hypothesis that needs behavioral testing.

Ontogenetic Development Related to Parental Care of a Neotropical Fish, Pterygoplichthys ambrosettii (Siluriformes: Loricariidae).

This study describes the main ontogenetic changes in the armored catfish Pterygoplichthys ambrosettii from newly hatched larva to adult. The relationship between the degree of development of newly hatched larvae and post-larvae and parental care is discussed. Ontogenetic series containing newly hatched larvae, post-larvae, and juveniles of P. ambrosettii were obtained from the Fish Culture Station of Universidade Estadual Paulista. Adult specimens were collected from the Preto River in the upper Paraná River basin. Morphological, osteological, morphometric, and meristic data and color pattern were analyzed. The species exhibited indirect development, with a distinct post-larval stage after the larval stage. Newly hatched larvae had a well-developed yolk sac and lacked pigmentation. The following characters underwent less change during development and can therefore be useful in taxonomical analyses: odontodes located posteriorly to the preopercle, number of plates on the lateral line, lower lip with three series of papillae, spots on the upper ray of the caudal fin, caudal fin similar to that of the adult, body ventrally covered with dermal plates and odontodes, small irregular spots on head, and typical ventral color pattern of the adult. The morphometric data revealed that most variation in body proportions occurred during less advanced developmental stages. Parental care influenced the ontogenetic development of newly hatched larvae.

Pachnoda iskuulka (Coleoptera: Scarabaeidae: Cetoniinae), a new species from Somaliland, including description of its mature larva.

Pachnoda iskuulka Král, Sommer Šípek, new species from the Sanaag region of north-eastern Somaliland is described. The new species is compared with the morphologically similar taxa Pachnoda abyssinica abyssinica Reiche, 1847, P. a. meriteti Di Gennaro, 2017, P. massajae Gestro, 1881, and P. werneri Beinhundner, 1992, all of which occur in the Horn of Africa. Relevant diagnostic characters (e.g., dorsal and ventral surface color pattern, male external genitalia) are illustrated. The third instar larva of the new species is described and biological notes are provided.

Colour variation between different lineages of a colour polymorphic lizard

AbstractColour polymorphic animals offer useful models to study the evolution of polymorphisms and studies with colour polymorphic lizards have contributed many advances in this field. Unfortunately, few studies address basic questions such as how observers (e.g. conspecifics) perceive the polymorphism or whether there is chromatic variability among evolutionary lineages or distant geographic areas within a species' range. The common wall lizard (Podarcis muralis) shows a striking colour polymorphism in its ventral surface, presenting up to five alternative colour morphs, that is white, yellow and orange/red (depending on the lineage), and two intermediate mosaic morphs: white‐orange and yellow‐orange. Here we compare this polymorphism in two geographically distant areas, the Po valley (Northern Italy) and the Eastern Pyrenees (Iberian Peninsula), corresponding to separate phylogeographic lineages. Using objective techniques of colour measurement and lizard vision models, we examine the chromatic differences between these two polymorphic lineages. We also search for chromatic differences in other colour traits present in P. muralis: the cryptic dorsal coloration and the ultraviolet‐blue spots of the outer ventral scales (UV‐blue OVS) used for intraspecific communication. Although we detected significant differences among lineages in colour variables, the main variation was found between the alternative ventral colour morphs. The most striking inter‐lineage divergence was between the orange Pyrenean morph and the red Italian morph, mainly caused by achromatic (but not chromatic) differences. In addition, although the UV‐blue OVS show strong chromatic and achromatic variation between lineages, the dorsal coloration shows the smallest degree of variation, and mainly between localities rather than lineages. Overall, the ventral colour pattern of P. muralis is shared by at least two geographically and phylogenetically distant lineages. Nevertheless, body coloration also shows signs of historical divergence (Pyrenean orange vs. Italian red) and local adaptation (mainly in the dorsal pattern).

Male Bicyclus anynana Butterflies Choose Females on the Basis of Their Ventral UV-Reflective Eyespot Centers.

Butterflies often use their dorsal and ventral wing color patterns for distinct signaling functions. Color patterns on hidden dorsal wing surfaces are often used in sexual signaling, while exposed ventral patterns are often used to ward off predator attacks. At rest, however, part of the ventral forewings are often hidden by the hindwings, allowing individuals to also use the patterns on this wing surface for sexual signaling. Here, we test this hypothesis in Bicyclus anynana (Butler, Lepidoptera, Nymphalidae) butterflies by first determining the degree of sexual dimorphism in ventral forewing patterns, focusing on the eyespots, from both wet and dry season forms, and then testing the role of the larger ventral forewing eyespots of dry season females in male mate choice. We also test male investment in reproduction. We show that ventral forewing UV-reflective eyespot centers, in addition to dorsal forewing eyespot centers previously examined in this species, play a role in sexual signaling as males preferentially mated with females with their ventral eyespot centers intact instead of blocked with black paint. This male preference, however, did not translate into a detectable higher reproductive investment via a single mating toward ornamented females. This study provides an example of how ventral forewing patterns, often hidden by hindwings, are used in sexual communication, in this case by females to attract males.

Apterous A specifies dorsal wing patterns and sexual traits in butterflies.

Butterflies have evolved different colour patterns on their dorsal and ventral wing surfaces to serve different signalling functions, yet the developmental mechanisms controlling surface-specific patterning are still unknown. Here, we mutate both copies of the transcription factor apterous in Bicyclus anynana butterflies using CRISPR/Cas9 and show that apterous A, expressed dorsally, functions both as a repressor and modifier of ventral wing colour patterns, as well as a promoter of dorsal sexual ornaments in males. We propose that the surface-specific diversification of wing patterns in butterflies proceeded via the co-option of apterous A or its downstream effectors into various gene regulatory networks involved in the differentiation of discrete wing traits. Further, interactions between apterous and sex-specific factors such as doublesex may have contributed to the origin of sexually dimorphic surface-specific patterns. Finally, we discuss the evolution of eyespot number diversity in the family Nymphalidae within the context of developmental constraints due to apterous regulation.

Revisão da distribuição geográfica, variação fenotípica e estado de conservação de Liolaemus fittkaui (Squamata: Liolaemidae), um lagarto endêmico dos Andes da Bolívia Central

O lagarto raro e endêmico da Bolívia Liolaemus fittkaui foi considerado extinto na localidade dos parátipos. Atualmente a espécie está classificada como Vulnerável. Discutimos a credibilidade da suposta localidade dos paratipos, assim como o evento de extinção relatado. As observações apresentadas evidenciam que a distribuição de L. fittkaui é mais ampla do que havia sido relatada, estendendo-se quase 100 km ao longo das regiões altas da Cordilheira de Tiraque (Províncias de Chapare, Tiraque e Carrasco). A espécie mantém populações em áreas em que seu habitat está bem-preservado, algumas delas encontradas dentro dos limites do Parque Nacional Carrasco. Essa nova informação seguindo os critérios da IUCN, indica que a categoria Vulnerável é adequada para o estado de conservação de L. fittkaui. Outros registros da província Arque pertencem a Liolaemus variegatus e a uma espécie da série de L. montanus. Descrevemos a variação do padrão de coloração ventral dos machos; diferentemente do ventre esbranquiçado originalmente descrito, os machos parecem ser polimórficos, apresentando coloração branca, amarela, vermelha e combinações intermediárias. A distribuição de L. fittkaui e de suas formas de coloração ventral reflete uma distribuição espacialmente fragmentada na qual a evolução intraespecífica poderia resultar em uma estrutura genética marcada. A persistência de L. fittkaui e de outros endemismos confinados às regiões altas andinas parece depender da preservação dos campos da puna, um ecossistema geralmente sub-representado nos esforços de conservação.

A Morphological Study ofCynops pyrrhogasterfrom the Chita Peninsula: Rediscovery of the “Extinct” Atsumi Race Endemic to Peninsular Regions of Aichi Prefecture, Central Japan

In the Japanese fire-bellied newt, Cynops pyrrhogaster, six local races were reported (Atsumi, Hiroshima, Kanto, Sasayama, Tohoku, and Intermediate) on the basis of morphological and ethological traits. Among them, the Atsumi race was reported only from a locality of the Atsumi Peninsula, Aichi Prefecture, but this race has been thought to be extinct after the 1960s. In the present study, we collected C. pyrrhogaster at a wetland of the Chita Peninsula, which is located west of the Atsumi Peninsula. The specimens resembled the Atsumi race in dorsal and ventral color pattern, absence of male nuptial color, small body size, and elongated filamentous process of tail tip. Newts from Chita differed from the Atsumi race in the tail height/tail length ratio, but this value was highly variable even among populations within another race (the Intermediate race). Judging from these results, we suggest that C. pyrrhogaster from the Chita Peninsula should be regarded as a part of the Atsumi race, which has long been thought to be extinct. Unfortunately, C. pyrrhogaster at Chita is also threatened with extinction, and immediate protection is seriously needed to prevent this enigmatic local race from complete extinction.

First record of South American suckermouth armored catfishes (Loricariidae, Pterygoplichthys spp.) in the Chumpan River system, southeast Mexico

Non-native South American suckermouth armored catfishes brackish waters of the genus Pterygoplichthys are reported in the Chumpan River in the Southeastern Mexico. The Pterygoplichthys in the Chumpan likely dispersed from populations from the drainage of nearby coastal rivers where they were already established. These catfish tolerate estuarine conditions and probably dispersed from the Grijalva-Usumacinta basin through the brackish waters of Laguna de Terminos and then ultimately entered the Chumpan River system. One juvenile and seven adult Pterygoplichthys were collected in the Chumpan River system in December 2014 from a river lagoon some 15 km upstream from Laguna de Terminos. Non-native catfish were not detected in the nearby Candelaria River. Based on their ventral color patterns, the captured adult catfish were identified as a mix of Pterygoplichthys pardalis and hybrid Pterygoplichthys disjunctivus × pardalis. The detection of these invasive catfish in the Chumpan River highlights the urgent need to generate an awareness program to reduce any adverse effects of this invasive species in the basin, and raises concerns that they may disperse to other basins via an oligohaline passageway in Laguna de Terminos.

HABITAT PREFERENCES AND VENTRAL COLOR VARIABILITY OF HIRUDO MEDICINALIS (CLITELLATA: HIRUDINIDA)

This study deals with the habitat preferences of medicinal leech Hirudo medicinalis Linnaeus, 1758 in the Czech Republic, in a highly agriculturally used and fragmented landscape, and provides the detailed information about the ventral coloration of this species. The study was conducted in 2010–2011 at 11 out of total 15 localities of H. medicinalis in the Czech Republic. At each locality a phytocenological sample of littoral and aquatic vegetation was recorded and physicochemical variables were measured. All captured leeches were measured and weighted, and a photo of ventral side was taken. Division of localities based on aquatic vegetation (TWINSPAN) formed groups of localities which corresponded to the population sizes of H. medicinalis. According to the abiotic factors localities with H. medicinalis were rich in carbon, poor in oxygen and situated in an area with warm climate. In this study four different ventral color patterns were described. During the ontogenetic development ventral side becomes darker, as indicated by the significant relationship between the percentage of dark color and leech size.

Validade da técnica de foto-identificação para analisar marcas naturais em Melanophryniscus montevidensis (Anura: Bufonidae)

Individual identification is useful for answering a variety of biological questions about animal life histories. Most of the techniques used to mark amphibians are invasive and can cause negative effects, compromising individual survivorship and biasing studies. Photo-identification consists in the identification of specimens based on photographic records of unique color-design patterns. This technique has been used with success in several amphibian species. Melanophryniscus montevidensis is an endangered anuran species inhabiting the Uruguayan Atlantic coast. The general pattern of coloration is black with red and yellow blotches on the belly. In this study, we validated the technique of photo-identification assisted by software for individual recognition in M. montevidensis using natural markings. Field trips were performed over 16 months during which, the ventral color pattern of specimens was photographed. The photos were edited and analyzed with the Wild-ID 1.0 software for photographic reconnaissance. An efficiency of 100% was obtained in the visual recognition and 90% in the detection of recaptures using the software. The use of photo-identification using natural marks is an effective technique in this species, because the color pattern of the belly was highly variable among individuals and remained unchanged in individuals over the 16 month period. In this evaluation the use of software for photo-identification was necessary for the treatment of large databases.