Snout-vent Length Research Articles

Hemoparasites Do Not Affect Life-History Traits and Cellular Immune Response in Treefrog Hosts Boana cordobae.

We provide the first evidence for hemoparasites in the endemic Cordoba treefrog Boana cordobae. We collected 37 adult frogs at 1200 m a.s.l. in the Comechingones Mountains in the Córdoba province (Argentina). Each individual was sexed, then snout-vent length and body mass were recorded, a toe was collected for skeletochronological age determination, and a slide with a blood smear was prepared for hemoparasite screening, before releasing the frogs in situ. A total of 81% (n = 30) of the frogs were infected by hemogregarines and trypanosomes with a high intensity of infections. Dactylosoma was found for the first time in Argentina. Hemoparasites had no significant effect on the leukocyte profile, which we assessed from the May-Grünwald-Giemsa-stained blood smears. The neutrophils/lymphocytes ratio, indicative of stress, was insignificantly higher (0.06) in parasitized frogs than in parasite-free individuals (0.04). Infected frogs were larger than the controls, but this effect vanished when correcting size data for age. Young frogs (first-breeders) dominated the age distribution of parasite-free individuals, suggesting that infection of frogs takes usually place after sexual maturation. Vectors transmitting hemoparasites to B. cordobae remain to be identified. We demonstrate that moderate to high intensities of hemoparasites do not significantly affect the cellular immune response of B. cordobae, or any of the life-history traits studied, nor did they show any external sign of disease.

Among the trees: shade promotes the growth and higher survival of juvenile toads

getation, including trees, significantly shapes microhabitats for amphibians due to the leaf litter input, providing stable shelter, creating a microclimate or indirectly through trophic interactions. It is known that some species can survive in a highly modified urban environment. Species associated with open space can find stable habitats in urban and human-transformed areas, but is the impact of shading (presence of canopy cover) significant in their case? We focus on the effect of solar exposure on the growth rate of juvenile green toads Bufotes viridis in fruit and canopy manipulation treatments. The main aim of the study was to examine the selected habitat traits promoting post-metamorphic growth of the green toad in semi-open enclosures. We investigated differences between exposure/land cover variants, i.e., sunny site (open area with direct solar exposure) and shadow site (shady site with a tree canopy cover). Using imitation fruits and real cherry plum Prunus cerasifera fruits (non-native tree species), we checked wheth­er amphibian growth is related to the additional structure that fruit lying on the ground created (a more heterogeneous surface structure) or to a trophic character (additional food source due to attracting inver­tebrates). We conducted a 40-day rearing experiment in three variants with two replications in semi-open enclosures with 20 juvenile toads each. We found differences in snout-vent length and body mass index in­vestigated due to site exposure during post-metamorphic growth. The survival rate of juvenile toads in the shaded site was higher than in sunny sites. We demonstrated a positive effect of the tree’s shade, regardless of the fleshy fruit’s presence on the ground. Toads benefit from developing at sites with reduced solar ex­posure (i.e., with a tree canopy), resulting in intensive growth and higher survival rate. Thus, there is an opportunity for planners and urban authorities to manage habitats for amphibian conservation purposes by creating a shaded zone, even for open habitat species, especially in transformed areas such as cities. Our results indicate that the beneficial effect of the lying fruit on the growth of juveniles is limited to specific conditions, and understanding this requires further research.

Hidden shifts in allometry scaling between sound production and perception in anurans.

Animal communication consists of signal production and perception, which are crucial for social interactions. The main form used by anurans is auditory communication, in most cases produced as advertisement calls. Furthermore, sound perception happens mainly through an external tympanic membrane, and plays an important role in social behavior. In this study, we evaluated the influence of body and tympanic membrane sizes on call frequency across the phylogeny of anurans. We use data on snout-vent length, tympanic membrane diameter, and dominant frequency of the advertisement call from the literature and from natural history museum collections. We mapped these traits across the anuran phylogeny and tested different models of diversification. Our final dataset includes data on body size, tympanic membrane size, and call dominant frequency of 735 anuran species. The best explanatory model includes body and tympanum size with no interaction term. Although our results show that call frequency is strongly constrained by body and tympanum size, we identify five evolutionary shifts in allometry from that ancestral constraint. We relate these evolutionary shifts to the background noise experienced by populations. Body size is important for myriad ecological interactions and tympanum size is strongly associated with female call frequency preferences. Thus, allometric escape in frog calls might arise through environmental selection such as breeding in fast flowing or soundscape competition, as well as sexual selection linked to tympanum size.

Discovery of a new species of dwarf frog (Anura: Ceratobatrachidae: Alcalus) extends the northwestern distributional limits of the genus to Northeast India

We describe a new species of the genus Alcalus from the northeast Indian state of Arunachal Pradesh based on molecular, morphological, and osteological characters. The new species differs from its congeners based on a combination of morphological characters including snout-vent length (27–28 mm in males; 29.9–36.2 mm in females), disc on fingers and toes with horizontal/transverse groove on the dorsal surface, dorsal skin wrinkled, and a pair of faint dorsolateral stripes on back. The new species also differs from its congeners by a DNA sequence divergence of 7.6–25.4% in the mitochondrial gene fragment 12S–tVal–16S rRNA (1533 base pairs). We include a detailed osteological description of the new species and compare it with the type of this genus. This is the first record of this genus from India, which was recently also reported from Myanmar and Western China. Discovery of a new species from northeast India indicates the need for a systematic study to uncover the hidden diversity of the Indo-Burma biodiversity hotspot. http://zoobank.org/urn:lsid:zoobank.org:pub:FB75F850-2AD9-4643-97CE-7F3F1D58E3F8 http://zoobank.org/urn:lsid:zoobank.org:act:6104F7A5-7E5E-42A7-90A1-810C394CFB3E

Trophic ecology of juvenile amphibians: relative level of myrmecophagy in two anuran species

ABSTRACT Research on trophic niche dimensions is essential to understanding the role of species in ecosystems. In the case of amphibian conservation, it is particularly important to study juveniles, given the vulnerability of this life stage. Here, the diets consumed by juvenile Rhinella arenarum and Odontophrynus sp. were evaluated, with special attention paid to the incidence of ants. Diet composition was quantified by analyzing the amphibians’ stomach contents. The representation of different taxonomic prey groups was determined, and the relationships between the amphibians’ morphological traits and the characteristics of their prey were explored. Diet composition and diversity differed between juveniles of the two species. Juvenile R. arenarum occupied an intermediate position along the specialist-generalist spectrum. Their most commonly consumed prey were ants (mainly Solenopsis and Linepithema) followed by mites. Juvenile Odontophrynus sp. had a more generalist diet. Their most commonly consumed prey were Isopoda followed by Coleoptera and miscellaneous larvae. Snout-vent length (SVL) was greater for juvenile Odontophrynus sp. than for juvenile R. arenarum, but the latter consumed more prey. The results suggest that juveniles of R. arenarum tend to specialize more on ants than do juveniles of Odontophrynus sp.

Notes on the pattern of head size in the Philippine Spotted Flying Lizard, Draco spilopterus (Weigmann, 1834), within Luzon Biogeographic Region, Philippines

Sexual head dimorphism is a condition where head morphology of male and female of the same species differ, which provides an additional way to recognise sex for species identification. Fifty four adult Philippine Spotted Flying Lizards, Draco spilopterus, were examined from four populations in the Luzon Island, Philippines to assess whether head morphometry can drive sexual dimorphism. We identified the sex and measured five morphometric measurements of the head (jaw length, jaw width, head height, head length, head width) and snout-vent length. A univariate analysis of the five morphometric measurements showed clear sexual dimorphism. Considering all individuals, female heads are significantly larger than those of males (all p-values < 0.05). We also revealed major differences in head size amongst the four populations due to their geographical location and habitat differences.

Impacts of isolated or mixed Roundup® Original DI and Boral® 500 SC herbicides on the survival and metamorphosis of Melanophryniscus admirabilis tadpoles

The bufonid species Melanophryniscus admirabilis is restricted to a single location in the southern Atlantic Forest, Brazil. Although the site of occurrence of M. admirabilis is covered with native forest and it is not directly exposed to pesticides application, the area is surrounded by agricultural activity. Our objectives were to evaluate possible alterations in morphological parameters (body mass, snout-vent length, and body index), metamorphosis (time to reach Gosner stages 42, 46 and to complete metamorphosis), and survival of M. admirabilis exposed to isolated Roundup® Original DI (R1: 234 and R2: 2340 µg.L−1 of glyphosate) and Boral® 500 SC, (B1: 130 and B2: 980 µg.L−1 of sulfentrazone) or mixed (R1+B1, R2+B1, R1+B2, R2+B2). Spawns of M. admirabilis were collected in natural lakes in the municipality of Arvorezinha and taken to laboratory cultivation. After the tadpoles acquired free swimming, the animals were acclimated for five days and fed ad libitum. The aquariums were contaminated with herbicides on the sixth day of cultivation, and the animals stayed in these aquariums for four days. Afterwards, the tadpoles were transferred to aquariums with clean water and monitored until metamorphosis (Gosner stage 46), when they were weighed, measured (snout-cloacal length) and cryoeuthanized. We observed no alterations in morphological parameters; however, survival was reduced in exposed groups (mortality index: 71 % in R2 and 29–64 % in mixed groups), suggesting energy allocation for metamorphosis at the expense of survival. Boral did not alter metamorphosis time. Roundup isolated and mixed with Boral altered the timing of Gosner stages 42 and 46 and reduced metamorphosis time, suggesting endocrine disruption. Thus, monitoring the presence and limiting the use of these pesticides in the area where M. admirabilis occurs can be crucial for conservation strategies.

Determination of Blood Biochemistry Reference Intervals in Eastern Collared Lizards (Crotaphytus collaris)

Abstract Eastern collared lizards (Crotaphytus collaris) are growing in popularity as exotic pets in the United States and worldwide. However, clinical biochemistry reference data to support interpretation of health and disease for this species remains lacking. This study evaluated 87 apparently healthy Eastern collared lizards (Crotaphtyus collaris). Blood samples were collected from the ventral coccygeal vein and assayed via Abaxis VetScan VS2 and Avian Reptile rotor. While lizard weight and snout-vent length (SVL) were normally distributed, most biochemical analytes, except albumin and total protein, were not. Many analytes were affected, albeit slightly, by lizard age, SVL, body condition score, gravidity and/or recent ovoposition, sex, health status, and color/locality. However, except for calcium, phosphorous, and albumin for gravid or immediately post oviposition females, biochemical values remained within the generated reference interval. Limitations of this study included that the VetScan VS2 avian / reptile profile plus rotor was unable to successfully provide values for bile acids for most of these apparently healthy lizards. When compared to biochemistry analyte values of lizards from the suborder Iguania from the western hemisphere, Eastern collared lizard biochemistries were similar for some analytes, but a relatively increased plasma glucose and uric acid occurs in this species which could affect the diagnosis of clinical disease or other health abnormalities.

Parasite-host relations and new reports of helminths for Rhinella dorbignyi (Duméril & Bibron, 1841) (Anura: Bufonidae) from Neotropical region

This study aimed to analyze helminth assemblage in Rhinella dorbignyi regarding host gender, size and mass in two sampling sites in southern Brazil, and to report new parasite associations. Anurans (n = 100) were collected in two localities from Rio Grande do Sul (RS) state, Brazil, from 2017 to 2020. Nineteen taxa (adults and larval forms) belonging to Nematoda, Acanthocephala, Digenea, and Cestoda were found in different infection sites. Cosmocercidae gen. Spp., Physaloptera liophis, Catadiscus sp., and Cylindrotaenia americana were the dominant taxa in helminth assemblage. Female anurans showed higher helminth species richness than males considering the total sample (two localities) or one of the two localities. However, prevalence and mean intensity of infection did not show any significant difference between genders. Mean intensity of infection was significantly higher (19.52) in Laranjal locality. Host body size does not influence helminth abundance, as infections did not show significant correlation snout-vent length (SVL) nor body mass (BM) of anurans. The findings reveal anurans of R. dorbignyi may be intermediate, paratenic and definitive host for these parasites. Plagiorchioidea helminths (Digenea), Physaloptera liophis, larvae of Acuariidae and Spiroxys sp. (Nematoda), and cystacanth of Lueheia sp. (Acanthocephala) constitute new records for R. dorbignyi. Additionally, this is the first record of Cylindrotaenia americana larvae in this host species. Resulting information increases the knowledge on biodiversity and parasite-host relations and may help future conservation programs developed in ecosystems in the extreme south of Brazil.

Diet of Invasive Rough Bent-Toed Geckos, Cyrtopodion scabrum (Heyden, 1827), in Southeastern Algeria.

Rough Bent-Toed Gecko, Cyrtopodion scabrum (Heyden, 1827), is an invasive species in Algeria and northwestern Africa. We provide detailed information on the morphometry and diet of C. scabrum from an urban area in Debila (northeastern Oued Souf), Algeria. We found a significant correlation between morphological characters (body length, snout-vent length, and tail length) in individuals within each sex, but no differences in morphometry between females and males. Analysis of stomach contents of 30 specimens (15 adult males, 15 adult females) resulted in identification of 198 prey items belonging to 2 classes, 8 orders, 20 families, and 29 genera. The diet of C. scabrum was mainly composed of arthropods and was highly diverse (Shannon index = 4.3). Insects were the main food item, accounting for 96.5% of prey consumed, followed by arachnids (3.5%). The most important prey categories were Hymenoptera (40.4%), Diptera (19.7%), Lepidoptera (12.6%), and Coleoptera (12.1%).

Age and growth of the mountain dragon, Diploderma micangshanense (Squamata: Lacertilia: Agamidae)

Abstract Knowledge of life history is important for understanding population ecology. The genus Diploderma is one of the most diverse genera in the family Agamidae, and no data on the life history traits of Diploderma species have been reported to date. Here, the age and growth of a population of D. micangshanense were revealed using skeletochronology for the first time. Females have greater snout-vent length (SVL) than males, but the mean SVL did not significantly differ between the sexes. Age ranged from one to four years in both sexes, and mean ages were 2.24 ± 0.10 years for males and 2.28 ± 0.12 years for females. No significant sexual differences were detected in either age structure or mean age. Age and body size were significantly positively correlated in both sexes. The growth coefficient k (males: 0.510; females: 0.441) and growth rate (males: 4.33 ± 0.38; females: 4.91 ± 0.39) were similar in both sexes. These results have implications for the population dynamics and management of this species.

Helminth parasitic ecology in Gymnodactylus geckoides Spix, 1825 (Squamata: Phyllodactylidae) from Caatinga domain, north-eastern Brazil

ABSTRACT Gymnodactylus geckoides is an endemic lizard from the Caatinga domain. However, the relationship of G. geckoides with its parasites remains largely unknown. Therefore, the present study aimed to identify the helminth fauna of G. geckoides in a Caatinga fragment and determine the influence of factors such as host morphology, sex, diet and seasonality on parasite load. The study was conducted at the Conservation Unit (CU) of the Catimbau National Park located in Catimbau, Pernambuco, north-eastern Brazil. In total, 83 individuals were captured, among which 43 (51.8%) were infected by the following helminths: Acanthocephala cystacanths (prevalence, 47%; mean intensity, 2 ± 3.99; mean abundance, 1.61 ± 3.25) and the nematodes Parapharyngodon alvarengai (prevalence, 15.7%; mean intensity, 1 ± 0.74; mean abundance, 0.25 ± 0.66), Physaloptera lutzi (prevalence, 2.4%; mean intensity, 4 ± 1.00; mean abundance, 0.10 ± 0.64) Physaloptera sp. (prevalence, 4.8%; mean intensity, 1 ± 0.00; mean abundance, 0.05 ± 0.24), and Spauligodon oxkutzcabiensis (prevalence, 3.6%; mean intensity, 1 ± 0.94; mean abundance, 0.06 ± 0.36). A significantly positive relationship was found between the intensity of infection by the most prevalent helminth (which belonged to Acanthocephala) and host morphology (snoutvent length) (β ± SE = 6.421 ± 1.555, z = 4.128, p < .001), as well as prey type (β ± SE = 0.256 ± 0.078, z = 3.251, p < .001). Acanthocephala infection had a higher intensity during the rainy season (Analysis of Variance1,81: p < .01) in both female and male hosts (ANOVA1,73: p = 0.21). The present study is the first to identify the ecological patterns of the host–parasite relationships of G. geckoides. The results of this study contribute to the knowledge of the parasitic fauna of lizards in the Neotropical region. http://www.zoobank.org/urn:lsid:zoobank.org:pub:0C037904-257A-40E1-9460-487B9FAFE786

Scaling relationships of maximal gape and prey size of snakes for an egg‐eating specialist (Dasypeltis gansi) and a dietary generalist (Pantherophis obsoletus)

AbstractThe size of both predators and prey can profoundly affect the foraging ecology of animals. This is especially true for snakes which consume prey whole. Although their gape imposes an anatomical limit on prey size, different snake species have a wide variety of prey types, prey sizes, and dietary breadth. To test whether a dietary specialist that only consumes bird eggs (Dasypeltis gansi) differed from a generalist that occasionally eats eggs (Pantherophis obsoletus), I quantified and compared the scaling relationships between overall size, cranial dimensions, and maximal gape and the orientation and mobility of relevant bones. Compared to P. obsoletus with a given overall size, D. gansi had maximal gape areas approximately 3–4 times greater and a significantly larger relative contribution to gape by the intermandibular (IM) soft tissues (50% vs. 19%). The greater distensibility of the IM soft tissues also allowed much greater lateral displacement of the distal end of the lower jaw in D. gansi versus P. obsoletus, but at maximal gape, the bones of these species had unexpectedly similar orientations in lateral view. The large gape of D. gansi was attained despite having a significantly shorter head than P obsoletus for a given snout–vent length. As a result of their large gape and more slender build, the predicted values of relative prey masses (RPM) for D. gansi at maximal gape vastly exceeded those of P. obsoletus for a given prey type. Although eggs are much stouter than rats, values of RPM at maximal gape for D. gansi eating eggs greatly exceeded those for P. obsoletus eating rats. Perhaps, Dasypeltis has the greatest size‐corrected gape and potential values of RPM (for a given prey shape) of any snake taxon as these values of D. gansi exceed those from all previously studied species with similar data.

Hematology and Biochemistry of the Española Lava Lizard (Microlophus delanonis)

This paper presents novel baseline health parameters on the Española lava lizard (Microlophus delanonis). Blood samples and morphological measurements were taken on 51 lizards (21 males, 30 females) captured from three locations on the island of Española. Morphologic parameters measured included body weight, snout-vent length, and temperature. Blood samples were analyzed approximately eight hours after collection using a portable blood analyzer (i-STAT) which measured hemoglobin, total CO2, glucose, lactate, sodium, potassium, and ionized calcium. Hematologic characterization data were obtained using standard laboratory techniques. There were significant differences found in snout-vent length, weight, heart rate, respiratory rate, total CO2, and heterophil percentage between males and females. The data presented here can be used to monitor the health of this population of lava lizards as well as help to understand the health of a related species, the San Cristóbal lava lizard (Microlophus bivittatus), which faces different evolutionary pressures including the presence of humans and feral cats. This study continues to widen our understanding of the Microlophus genus; however, further research should be done to characterize the remaining species that inhabit the islands in the Galápagos archipelago.

Doğu Akdeniz, Türkiye'deki Su Kurbağalarının (Pelophylax ridibundus-complex) Üreme Ekolojisi ve Larval Gelişimi

Reproductive biology of Marsh frogs (Pelophylax ridibundus s.l.) was investigated in the Eastern Mediterranean Region of Türkiye in terms of reproductive phenology, fecundity, clutch size, reproductive effort, and mate choice. Frogs are active for approximately ten months throughout the year and hibernate between November and January. Breeding occurs from mid-January until early June and metamorphosis took 45-65 days, with juveniles observed from the end of March. The tadpole reaches its largest size at stage 38, with a mean total length of 60.61 mm and juveniles have an average snout-vent length of 20 mm at the end of metamorphosis. Secondary sexual characters can be observed on individuals reaching 45 mm snout-vent length and we could not detect any amplexed pairs below this length. The clutch size of spawned egg masses ranged between 144 – 645 and the mean egg size was calculated as 1.73 mm. The mean fecundity was 3853 (ranging between 940 and 6000) eggs and the reproductive effort was 0.094 in females. Females were approximately 16% larger than males and the snout–vent length of males and females of amplexed pairs is significantly different but not correlated. These findings signify random mating instead of size-assortative mating. However, the preference of 6.8% larger females than single ones to mate indicates a size-dependent mating for Western Mediterranean population.

The relationship between temperature, growth rate and body condition of Bufo bufo toadlets prior to their first hibernation

Abstract The effect of environmental temperature on the growth and body condition of common toad (Bufo bufo) toadlets was studied during their first terrestrial growth season, following metamorphosis, at a pond in south Dorset, UK, between 2010 and 2021. Toadlet samples were collected annually on the first day of emergence and then approximately once a week until late September/early October. In total, 15-19 samples were collected annually depending on the duration of the toadlet activity season. Toadlet snout-vent length (mm) and body mass (mg) of each captured toadlet was measured and their body condition (Scaled Mass Index: SMI) estimated both annually and for each annual quarter season. Toadlet growth rate and SMI varied between years and were significantly correlated with the duration of their first growth season and its lowest recorded temperature. Growth rate declined as the duration of the growth season increased whilst the reverse was true for SMI. Growth rates also increased as temperatures increased and vice versa for SMI. SMI was inversely correlated to growth rate and suggest that toadlets may enter their first hibernation larger, but in poorer condition, following warm summers than cool summers, and that this may have the potential to reduce their survivorship during a following mild winter. Assuming that similar relationships, between growth rates, body condition and environmental temperatures are not restricted to toadlets during their first terrestrial growth season, then this scenario may also be applicable to subsequent juvenile stages, further increasing the potential consequences for individual survival and fitness.

A new species of green tree frog of the genus Gracixalus (Anura: Rhacophoridae) from the evergreen forest of Northeast India

Abstract We describe a new species of rhacophorid frog of the genus Gracixalus from northeast India based on molecular, morphological and acoustic evidence. The new species, formally described herein as Gracixalus patkaiensissp. nov., is morphologically distinct from other congeners by a suite of morphological characters such as snout-vent length 23.6–26.5 mm in adult males; green dorsum with irregular brown spots; dorsal skin shagreened with numerous spinules; snout shape nearly acuminate in dorsal and ventral view; a prominent dark streak along the cranial margins; white reticulations along lateral side and ventrum distinct in life. Genetically, the new taxon is found to differ from all the recognized Gracixalus species by 4–14.8% divergence in the 16S mitochondrial gene. The discovery confirms the presence of genus Gracixalus from the Indian state of Arunachal Pradesh underlines the importance of biological exploration even in well-known protected areas of India.

“Anteaters” under the airport: a slender new species of blindsnake, genus Indotyphlops, from Timor-Leste (Scolecophidia: Typhlopidae: Asiatyphlopinae)

We describe a slender immature female blindsnake from the main airport in Dili, Timor-Leste, as a new species of Indotyphlops, adding a third species to the country's known blindsnake fauna of Sundatyphlops polygrammicus (Schlegel, 1839) and Virgotyphlops braminus (Daudin, 1803). The new species has the following combination of characteristics: small size (snout–vent length = 119 mm), slender body (relative body thickness 71), T-V supralabial imbrication pattern, relative rostral width 0.36, 434 middorsal scales, relative tail length 1.7%, absence of enlarged occipital scales, and apical spine absent. The snake was found in an ant nest under several flat rocks near the fuel depot of Nicolau Lobato International Airport, and this habitat and the discovery in a busy location with heavy human impacts indicate that the species is likely a primarily subterranean myrmeco- or termitophage.

A new species of Andean frog of the genus Phrynopus (Anura: Strabomantidae) from southeastern Peru.

The Cordillera de los Andes is one of the most important regions for biodiversity. Among amphibians, many endemic species of terrestrial-breeding frogs have recently been discovered. Herein we describe Phrynopus sancristobali from the Andes of southeastern Peru based on molecular and morphological data. The new species is known from the ecotone between humid puna and montane forest at 3910 m a.s.l. on the left side of the Apurímac Valley in the Department of Ayacucho. The new species differs from congeners by having dorsum bearing pustules and light brown with dark brown reticulations surrounding the areolas, and coloration consisting of flanks golden brown with gray or dark brown marks, palms pale orange, soles deep orange, toes IV and V dark brown in dorsal and ventral view, belly cream to yellow with gray to light brown marks, and groin and throat deep orange. The snout-vent length (SVL) is 20.7 and 22.2 in two females, and 19.5 mm in one male. According to our phylogeny inferred using Maximum Likelihood with a concatenated dataset of three mitochondrial and two nuclear genes, P. sancristobali is sister taxon of P. apumantarum, recently described from Department Huancavelica. Our description extends the known geographic range of Phrynopus 73 km to the south, and P. sancristobali is the only species in the genus known to occur south of the Mantaro River, whose deep valley is hypothesized to be a biogeographic barrier for high-Andean organisms. The discovery of P. sancristobali confirms the high levels of endemism and beta diversity of Phrynopus in the moist puna grasslands and montane forests of the high Andes of Peru, and suggests that further work will reveal the presence of additional species in southern Peru.

Feasibility and application of using Texas horned lizard scat to predict lizard size and age class

AbstractTexas horned lizards (Phrynosoma cornutum; hereafter THL) were once abundant throughout Texas; however, their distribution and abundance have decreased, and currently they are listed as a threatened species in the state. Detection of THL can be difficult because of their cryptic nature and sporadic distribution. Using indirect signs such as fecal pellets (i.e., scat) to determine occupancy is a widely practiced survey technique. However, it is unknown if scat size can be used to determine the age structure of THL. Our objectives were to determine 1) if THL scats were consistently produced and at consistent size in relation to lizard snout‐vent length (SVL), 2) if THL scats remain intact in the environment, and 3) if scat length and diameter could be used as an indicator of THL size, which could be used to determine population age structure. We tested the feasibility of using scat morphometrics to estimate age class ratios, body size, and population estimates for THL. Data collection was conducted in 3 phases, which occurred from 2001–2019. Scats were collected daily for 6 days from 6 hatchling, 10 juvenile, and 10 adult THL collected from southern Texas. Texas horned lizards were measured for snout‐to‐vent length (mm) and categorized as either hatchling, juvenile, or adults based on estimates from the literature. On average, THL produced one scat/day, typically in the morning. Scat length and width increased as lizard size (i.e., SVL) increased with each age class. Scat size of each age class of THL was consistent between days; thus, objective one was met. Scats were measured for length and width (mm) and placed in direct sunlight for 90 days, submerged in water for 2 days, and placed in typical summer weather conditions of southern Texas. Texas horned lizard scat did not shrink or swell in size or decay due to environmental conditions during the 90‐day experiment. Thus, THL scats do remain intact in the environment. We collected scat from 70 known‐size THL from south‐central Texas. Simple log‐log regression models demonstrated a linear relationship (r2 = 0.89) between loge (SVL) and loge (scat length, mm). Slopes were similar among age classes, but intercepts differed as expected. We tagged individual THL to follow growth rates through time. Thirteen of 20 tagged females produced 178 hatchlings, of which 56, 23, 19, and 6 were recaptured during their hatchling, 2nd, 3rd, and 4th year, respectively. Models for growth rates of known‐age THL were not equal (F6,69 = 44.6, P &lt; 0.0001) among age classes. Growth rates were faster in year 1 (0.101 ± 0.003 mm d−1) and year 2 (0.099 ± 0.007 mm day−1) and slowed (0.076 ± 0.009 mm day−1) during their 3rd year. Scat from THL reliably can be used to estimate population age class structure, body size, and population estimates. However, our growth rate analyses suggest that THL appear to experience slower growth rates than during previous decades, and thus, THL require reevaluation as to what SVL size constitutes an adult THL.