Hypsiboas Pulchellus Research Articles

Alimentación de dos especies de anfibios (Anura: Hylidae) en la estación de bajas temperaturas y su relación con la acumulación de energía en Santa Fe, Argentina

Feeding of two amphibian species (Anura: Hylidae) during the low temperatures season and its relationship with energy storage in Santa Fe, Argentina. In environments with thermal and pluvial seasonality such as those of the Middle Paraná River floodplain (Province of Santa Fe, Argentina), most amphibian species reproduce during the warm season and drastically diminish their activity during winter. Even though, a few species remain active during the cold season, such as Hypsiboas pulchellus that has its reproductive peak during the autumn-winter period (and the consequent energy demand). The objective of this study was to analyze and compare the feeding and development of fat bodies during the low temperature season for H. pulchellus and Dendropsophus nanus. We analyzed entire gastrointestinal tract contents of both species (H. pulchellus = 110 specimens; D. nanus = 114 specimens) and applied an index (IRI%) that combines prey abundance, volume and frequency to describe frogs diets; we used fat bodies weights as indicators of stored energy reserves. We compared diet between species with a niche overlap index (Ojk: 0-1) and used null models to ascribe statistical significance to evaluate overlap; and we analyzed variation in empty guts proportions through months and between species. Also, using ANCOVAs we explored differences in fat bodies, number and volume of prey consumed along months, between species and sexes. The most important preys in H. pulchellus diet during the cold season were Araneae (IRI% = 34.96), Chironomidae (IRI% = 33.08), Tipulidae (IRI% = 11.44) and Gryllidae (IR1% = 7.31); while for D. nanus, Chironomidae (IR1% = 48.14), Tipulidae (IRI% = 18.41), Psychodidae (IRI% = 7.44) and Araneae (IRI% = 7.34). Diet overlap between species was elevated (Ojk=0.78) and higher than expected by chance (mean simulated indices: Ojk = 0.04; p[observed > or = expected]<0.01; p[observed < or = expected] = 1). In H. pulchellus there was a monthly variation in number of prey per gut, while in D. nanus there was a difference in fat bodies development between sexes. Fat bodies development, number of prey per gut and preys volume also varied between species. Despite diet similarity between H. pulchellus and D. nanus, each species showed a different strategy to accumulate energy and support their activity during the cold season. The low rate of gastrointestinal emptiness in H. pulchellus (< 10% in any analyzed month) together with the poor development of their fat bodies, allows us to point out that, to sustain the breeding elevated energy demands, this species continues with a high feeding rate even at the low temperatures of cold season. On the other hand, the rate of gastrointestinal emptiness of D. nanus was higher than that of H. pulchellus (May = 17.24%, July = 22.22% and August = 35.71%), while their fat bodies were well developed. Thus, D. nanus would depend more on their stored reserves to sustain the energy demands of being active during the low temperatures season and hence would reach the reproductive season in spring-summer in good body condition.

Cholinesterase activities and behavioral changes in Hypsiboas pulchellus (Anura: Hylidae) tadpoles exposed to glufosinate ammonium herbicide

In this study, amphibian tadpoles of Hypsiboas pulchellus were exposed to herbicide Liberty®, which contains glufosinate ammonium (GLA), for 48 h to the following concentrations: 0 (control), 3.55, 4.74, 6.32, 8.43, 11.25, 15, 20, 26.6, and 35.5 mg GLA L(-1). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities, as well as swimming capabilities (swimming speed and mean distance) were measured in tadpoles whose concentrations displayed survival rates > 85 %. Our results reveal that sublethal concentrations of GLA significantly inhibited both AChE and BChE activities in tadpoles with respect to the control, showing a concentration-dependent inhibitory effect. The highest inhibition percentages of AChE (50.86%) and BChE (53.02%) were registered in tadpoles exposed to 15 mg GLA L(-1). At this concentration, a significant increase of the swimming speed and mean distance were found in exposed tadpoles with respect to the control, as well as a negative and significant correlation between swimming speed and BChE activity, thus suggesting that this enzyme inhibition is related to an increase in swimming speed. Therefore, exposure of tadpoles to GLA in the wild at concentrations similar to those tested here may have adverse consequences at population level because neurotransmission and swimming performance are essential for tadpole performance and survival.

Abnormalities in amphibian populations inhabiting agroecosystems in northeastern Buenos Aires Province, Argentina

The occurrence of abnormalities in amphibians has been reported in many populations, and its increase could be related to environmental pollution and habitat degradation. We evaluated the type and prevalence of abnormalities in 5 amphibian populations from agroecosystems with different degrees of agricultural disturbance (cultivated and reference areas). We detected 9 types of abnormalities, of which the most frequent were those occurring in limbs. The observed prevalence of abnormality in assessed populations from cultivated and reference areas was as follows: Rhinella fernandezae (37.1 and 10.2%, respectively), Leptodactylus latrans adults (28.1 and 9.2%) and juveniles (32.9 and 15.3%), and Hypsiboas pulchellus (11.6 and 2.8%). Scinax granulatus populations did not show abnormalities. Pseudis minuta, which was only detected in the reference area, exhibited a prevalence of 13.3%. For R. fernandezae, L. latrans, and H. pulchellus, generalized linear mixed models showed that prevalence of abnormalities was significantly higher (p < 0.05) in cultivated than in reference areas. L. latrans juveniles were more vulnerable to abnormalities than adults (p < 0.05). The presence of abnormalities in some species inhabiting different agroecosystems suggests that environmental stress factors might be responsible for their occurrence. While we detected pesticides (endosulfan, cypermethrin, and chlorpyrifos) and lower dissolved oxygen levels in ponds of the cultivated area, no data are currently available on how other factors, such as injuries from predators and parasite infections, vary by land use. Further research will be necessary to evaluate possible causes of abnormalities detected in the present study mainly in the context of factor interactions.

Evidence of Reduced Feeding and Oxidative Stress in Common Tree Frogs (Hypsiboas pulchellus) from an Agroecosystem Experiencing Severe Drought

The intensification of modern agriculture may impact amphibian populations through habitat loss and the direct and indirect effects of the pesticides upon which it relies. The increased homogeneity of modern agricultural landscapes may be detrimental in times of extreme low and high temperatures associated with climate change, as refuge abundance and habitat connectivity decrease. In this study, we evaluated the impacts of the herbicide glyphosate and subsequent intense drought on the Common Tree Frog, Hypsiboas pulchellus, inhabiting an agricultural landscape. We examined a series of organismic indices (stomach content index, hepatosomatic index, body fat index, gonadosomatic index, condition factor) as well as biomarkers of oxidative stress (hepatic catalase activity and reduced glutathione [GSH] content), exposure to contaminants (hepatic gluthatione-S-transferase activity), and genotoxicity (frequency of micronuclei). No significant differences were observed in the parameters measured when comparing frogs sampled before, 2, and 15 days after glyphosate exposure. However, anurans sampled in the same site two months later, when a drought was at its peak, presented a decrease in stomach content and hepatosomatic index, as well as an increase in hepatic catalase activity, hepatic GSH content and micronuclei frequency in peripheral circulating erythrocytes. Our findings demonstrate that drought is challenging to these anurans in this environment as evidenced by an apparent reduction in food intake and oxidative stress.

Invasive bullfrogs as predators in a Neotropical assemblage: What frog species do they eat?

Anurans are important prey for the American bullfrogLithobates catesbeianus, but field assessments of its diet in the context of a local prey assemblage are lacking. We aimed to identify the frog species consumed by an invasive bullfrog population in subtropical South America, and to assess their relative importance among other types of prey. Characterization of the frog assemblage in the study area also allowed us to calculate the degree of electivity of the recorded anuran prey, in order to gain insight regarding bullfrog feeding preferences and to test if the bullfrog prey composition differed from a random sample of the assemblage. A total of 32.6% of the bullfrogs had at least one anuran in the stomach contents, and post-metamorphic anurans represented 49.1% of the relative prey importance for adult bullfrogs. Anurans were preyed on by all size classes, and constituted the volumetrically most important prey category in the diet of individuals heavier than 100 g. Cycloramphidae, Hylidae and Leiuperidae were positively selected, andHypsiboas pulchellusandPhysalaemus cuvieriwere the species most often taken. We found a low occurrence of cannibalism, despite the high density of bullfrogs at the study site. Our results showed that the degree of electivity differed among bullfrog prey types, suggesting that some frog species may be preyed on in a higher proportion than their relative abundance in the assemblage. Testing the clues provided by this assemblage-level approach may lead to a better assessment of the interactions between bullfrogs and the native frog fauna.

Trophic Niche Variation and Individual Specialization inHypsiboas pulchellus(Duméril and Bibron, 1841) (Anura, Hylidae) from Uruguay

6 Corresponding author. ABSTRACT. Intrapopulation variation includes age and sexual variation, but also individual niche specialization. Individual specialization has important effects on dynamics at population or community levels. Environmental variation and intraspecific interactions are factors that can promote or enhance this kind of variation. Despite its relevance, knowledge about individual specialization in amphibians is still scarce, especially in species from temperate regions. In this study we analyzed the intrapopulational variation of the trophic niche in Hypsiboas pulchellus from a population in southern Uruguay. Particularly, we analyzed ontogenetic and sexual variation and individual specialization of the diet. We found ontogenetic variation in diet as a result of a shift from flies to beetles with increasing body size of frogs, but there were no differences in diet between males and females. We also found evidence of individual specialization, which varied seasonally together with population trophic niche width; during the warm season (October-March), individual specialization and population TNW both increased.

Reduced body condition and enzymatic alterations in frogs inhabiting intensive crop production areas

Parameters indicative of general condition and health were compared amongst adult frogs inhabiting uncultivated lands and fields subjected to agricultural practices typical of the humid pampas of Argentina. Whereas no significant differences existed in the parasite load and external malformations prevalence rate of adult frogs from either environments, a reduced condition factor was clearly demonstrated in frogs from agricultural lands. This conclusion was reached for four frog species of different life habits: the terrestrial fossorial Rhinella fernandezae, the terrestrial Leptodactylus latinasus, the semi-aquatic Leptodactylus ocellatus, and the arborescent Hypsiboas pulchellus. A distinct pattern of enzymatic modifications was furthermore observed in L. ocellatus and H. pulchellus from agricultural lands, including elevated hepatic activities of catalase and cholinesterase, and an inhibition of liver GST activity. Further studies should investigate the causes and consequences of the systematically low condition factor observed in frogs from agricultural fields of the humid pampas of Argentina.

Linking amphibian call structure to the environment: the interplay between phenotypic flexibility and individual attributes

The structure of the environment surrounding signal emission produces different patterns of degradation and attenuation. The expected adjustment of calls to ensure signal transmission in an environment was formalized in the acoustic adaptation hypothesis. Within this framework, most studies considered anuran calls as fixed attributes determined by local adaptations. However, variability in vocalizations as a product of phenotypic expression has also been reported. Empirical evidence supporting the association between environment and call structure has been inconsistent, particularly in anurans. Here, we identify a plausible causal structure connecting environment, individual attributes, and temporal and spectral adjustments as direct or indirect determinants of the observed variation in call attributes of the frog Hypsiboas pulchellus. For that purpose, we recorded the calls of 40 males in the field, together with vegetation density and other environmental descriptors of the calling site. Path analysis revealed a strong effect of habitat structure on the temporal parameters of the call, and an effect of site temperature conditioning the size of organisms calling at each site and thus indirectly affecting the dominant frequency of the call. Experimental habitat modification with a styrofoam enclosure yielded results consistent with field observations, highlighting the potential role of call flexibility on detected call patterns. Both, experimental and correlative results indicate the need to incorporate the so far poorly considered role of phenotypic plasticity in the complex connection between environmental structure and individual call attributes.

Predator–prey interactions between Synbranchus marmoratus (Teleostei: Synbranchidae) and Hypsiboas pulchellus tadpoles (Amphibia: Hylidae): Importance of lateral line in nocturnal predation and effects of fenitrothion exposure

Environmental contaminants can disrupt interactions between aquatic species by altering community structure. We explored predator–prey interactions between marbled swamp juvenile eels ( Synbranchus marmoratus; predator) and anuran tadpoles ( Hypsiboas pulchellus; prey) in relation to two aspects: the importance of lateral line in the predator and whether the absence of light modifies predation rates; and the effect of a sub-lethal concentration of fenitrothion on both predator and prey. Eels were tested under two sensory conditions (lateral line intact and lateral line blocked by cobalt chloride) in dark conditions. Predation rates were evaluated using different treatments that combined predator and prey exposed or not to insecticide. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were also measured in muscle samples of eels and tadpoles to explore whether fenitrothion affects predator and prey differentially. Marbled swamp eels were more efficient in feeding on tadpoles during the night than during the day, showing that lateral line makes an important contribution to prey detection and capture. Regarding pesticide effects, short-term (6 h) exposure to an ecologically relevant fenitrothion dose of 2.5 mg L −1 altered the predator–prey relationship by changing prey behaviour, reducing prey detection and therefore increasing tadpole survival. At this concentration, the outcome of the predator–prey relationship appears biased in favor of the exposed tadpoles, which were released from predation risk, despite their altered behaviour and the higher inhibition percentages of tail BChE (70%) and AChE (51%) than in control individuals. Our study involving these model species and agrochemicals demonstrates that fenitrothion affected the outcome of a predator–prey relationship. Further studies are needed, in these species and other native amphibians, to investigate the nature of the mechanisms responsible for the adverse effects of pesticides on antipredator behaviour and predation efficiency.

Flexibility in the advertisement call of Hypsiboas pulchellus (Anura: Hylidae) in response to microhabitat characteristics.

The structure of the environment determines patterns of signal degradation and attenuation, potentially affecting communication. The expected adjustment in call structure improving signal transmission in an environment was formalized in the acoustic adaptation hypothesis. Within this framework, most studies considered anuran calls as fixed attributes determined by local adaptations. However, intra‐individual variability in vocalizations has also been reported. Evidence is presented here for phenotypic flexibility in the advertisement call of Hypsiboas pulchellus in response to induced changes in microhabitat structure. Males were recorded in free‐field conditions. Microhabitat was then modified, placing a styrofoam enclosure around each calling male, re‐recording calls therein. Student tests for independent samples (intra‐individual variation) and paired samples (inter‐individual variation) rendered similar results. All temporal variables were significantly longer when individuals were broadcasting inside the enclosure. Spectral attributes were also subject to modulation, although the magnitude and direction of these adjustments were inconsistent among males. Playback experiments within the enclosure yielded results which rule out treatment‐induced variation, highlighting the potential rôle of call flexibility on detected call patterns. This study questions the view of fixed adaptations as the sole determinant of the match between call and environment, positing phenotypic flexibility as a main determinant of this interplay.

Systematics of Andean gladiator frogs of the Hypsiboas pulchellus species group (Anura, Hylidae)

We revisit the taxonomic status of Andean species and populations of frogs of the Hypsiboas pulchellus group using multiple lines of evidence potentially indicative of evolutionary lineage divergence in anurans: differences in qualitative morphological or bioacoustic character states, no overlap in quantitative characters of advertisement calls, and monophyly of gene genealogies. We found qualitative and quantitative morphological characters to be extremely variable among species and populations of the group and thus of very limited use in assessing lineage divergence. In contrast, phylogenetic analyses based on 16S rRNA and cytochrome b sequences resolved highly supported clades that are in concordance with bioacoustic differences. The results support the specific distinctness of most nominal species recognized in the group, including the Bolivian Hypsiboas balzani and Hypsiboas callipleura, two species that were considered to be synonymous, and revealed the presence of an undescribed species from southern Peru, which is here described as Hypsiboas gladiator sp. n. In contrast, Hypsiboas andinus and Hypsiboas riojanus were mutually paraphyletic, and showed no differences in morphology and acoustic characters. Consequently, we regard the former as a junior synonym of the latter. However, we discovered that populations of H. riojanus from central Bolivia exhibit some degree of genetic differentiation and advertisement call differences with respect to Argentine populations, but sampling of these Bolivian populations is too sparse to draw taxonomic conclusions. Our phylogenetic results support the hypothesis that ancestral lineages of the Andean H. pulchellus group experienced successive splitting events along a latitudinal gradient from north to south.

Lethal and sublethal effects of cypermethrin to Hypsiboas pulchellus tadpoles

The study of the effects of the insecticide cypermethrin (CY) technical grade and its Sherpa® commercial formulation on Hypsiboas pulchellus tadpoles assessing lethality, behavior, growth, and abnormalities under standardized laboratory conditions is reported. Observed behaviors were identified and categorized by means of a ranking system according to the loss of mobility. Results of acute lethal effects indicate higher potency for Sherpa® at this level of assessment. All effects on behavior showed an increasing degree of injury as insecticide concentration increased. Organisms exposed to technical grade CY showed lower body length with respect to controls from 3.44 µg CY/L to higher concentrations, whereas those exposed to Sherpa® exhibited lower growth from 0.83 µg CY/L. Both forms of the tested insecticide caused abnormalities between 0.34 and 4.18 µg CY/L, but 100% of malformed individuals was detected from 34.4 µg CY/L for those exposed to the technical grade CY, and from 8.36 µg CY/L for those exposed to Sherpa®. This study proposes the use of easily identifiable and distinguishable sublethal end-points. The high input loads of CY in natural environments, the detected concentrations in the field, in addition to the low levels of this insecticide required to induce sublethal effects (which could eventually lead to death), allow for the conclusion that the insecticide is a risk factor for amphibians inhabiting agroecosystems.

A New Andean Species of the Hypsiboas pulchellus Group: Adults, Calls, and Phylogenetic Relationships

Abstract We describe a new species of the Hypsiboas pulchellus Group from the eastern Andes of central Peru (Region Pasco). Calls of both H. melanopleura and the new species are described. The new species is more similar to H. melanopleura and H. palaestes but differs in morphological characters and in coloration pattern. The new species and H. melanopleura are included in a molecular phylogenetic analysis of the H. pulchellus Group that shows them to be sister species and forming a second, independent, Andean clade within the group. New collecting sites for H. melanopleura are provided with the first record in the Region of Junin and the distribution of H. melanopleura, H. palaestes, and the new species is illustrated in a map.

Chytridiomycosis in frogs from Uruguay

Amphibian chytridiomycosis caused by Batrachochytrium dendrobatidis is reported in Uruguayan native amphibians for the first time. Histological evidence of infection was observed in tadpoles of Hypsiboas pulchellus, Odontophrynus maisuma, Physalaemus henselii, and Scinax squalirostris. The effects of chytridiomycosis on these species are still unknown. However, the disease is of potential concern for the conservation of the apparently declining species P. henselii and also for O. maisuma, given its restricted distribution in habitats which are being increasingly disturbed.

Impact of endosulphan and cypermethrin mixture on amphibians under field use for biotech soya bean production

This study presents results at a local scale of the impact of pesticide aerial applications containing a mixture of endosulphan and cypermethrin on anurans assessed by means of field evaluations. Additionally, effects were compared with laboratory toxicity tests in standardised conditions. Field assessment with native population allowed the detection of dead anuran larvae of the species present in the stream of water after fumigation, in coincidence with the decrease in the frequency of live larvae (p < 0.01) from sampling nets. Cage experiments showed significant differences (p < 0.01) in anuran larvae survival before and after fumigations. Laboratory acute toxicity tests with endosulphan formulation demonstrated sublethal symptoms in Hypsiboas pulchellus larvae 24 h after initial exposure time. The 96 h LC-50 was 0.13 µg endosulphan/litre, which is over 1000 times lower than the cypermethrin LC-50 value. Endosulphan seems to be the insecticide responsible for the drastic effects on anuran larvae detected in the field during studied events.

A new species of Hypsiboas (Anura: Hylidae) from the atlantic forest of Santa Catarina, southern Brazil, with comments on its conservation status

Abstract A new species of Hypsiboas is described from the Atlantic Forest in Santa Catarina State, southern Brazil. The new species is morphologically similar to Hypsiboas marginatus, from which it differs by its smaller size, flanks with white blotches, a white stripe on the upper lip exceeding posteriorly to the tympanum, a white dorsolateral stripe reaching the inguinal region, tadpole with body black, tail whitish-yellow translucent, and labial tooth row formula 2(2)/5(1). The new species inhabits Atlantic Forest environments within mountain ranges from eastern Santa Catarina State, denominate Serras do Leste Catarinense, while H. marginatus occurs in the Serra Geral mountain range, in southern Santa Catarina and northeast Rio Grande do Sul State, and thus have allopatric distributions. The new species is included in the Hypsiboas pulchellus species group, and its relationship with other members of the group is discussed herein. We also discuss the conservation status of the new species in relation to...

Vocalizations and comments on the relationships of Hypsiboas ericae (Amphibia, Hylidae)

The vocalizations of Hypsiboas ericae (Caramaschi &amp; Cruz, 2000) are described and new information on the external morphology and osteology of the species are presented. H. ericae presents a bony spine in the prepolex and the individuals can present green or brown dorsal color, as other species of the Hypsiboas pulchellus (Duméril &amp; Bibron, 1841) species group. The vocalizations of H. ericae are similar to the vocalizations of Hypsiboas bischoffi (Boulenger, 1887), Hypsiboas guentheri (Boulenger, 1886), and other species in the H. polytaenius (Cope, 1870 "1869") clade of the H. pulchellus species group, but some osteological aspects are different to those found in the majority of the species of this group.

A New Species of Hypsiboas from The Atlantic Forest of Southeastern Brazil (Amphibia: Anura: Hylidae)

We describe a new species of Hypsiboas of the Hypsiboas pulchellus species group from highland streams of the Atlantic Forest of southeastern Brazil. Vocalizations, egg-mass, and tadpole are also described. We compared the new species with other species of the Hypsiboas pulchellus species group. The new species is most similar to Hypsiboas semiguttatus, its sister species, and Hypsiboas curupi, from which it differs in advertisement call and larval morphology. We provide information on natural history, phylogenetic relationships, embryos, geographic distribution, and conservation.

Redescription of Hypsiboas Semiguttatus, with the Description of a New Species of the Hypsiboas pulchellus Group

We redescribe Hypsiboas semiguttatus (Lutz, 1925) and describe its tadpole and vocalization. We also describe a new species, previously confused with H. semiguttatus from Misiones, Argentina, and potentially from Brazil. This new species differs from H. semiguttatus in being more robust, having a tadpole with complete marginal papillation (no anterior gap), and a labial tooth row formula of 3/5. We discuss the status of populations previously assigned to H. semiguttatus and discuss the relationships of the new species within the Hypsiboas pulchellus group.

Acute and chronic effects of Cr(VI) on Hypsiboas pulchellus embryos and tadpoles

In the last few years there has been great concern about declines in the abundance of several species of amphibians around the world. Among amphibians, anurans have a biphasic life cycle, with aquatic tadpoles and generally terrestrial adults, and they have an extremely permeable skin, making them excellent indicators of the health of the environment. A number of different causes have been suggested for the global decline of anurans, the pollution of their habitat by chemical stressors being considered one of the major factors. Among chemical stressors, heavy metals are known for their high toxicity at very low concentrations. This study assessed short- (96 h, 'acute') and long-term (1272 h, 'chronic') exposure to Cr(VI) at lethal (3 to 90 mg 1(-1)) and sublethal concentrations (0.001 to 12 mg 1(-1)) on Hypsiboaspulchellus (previously called Hyla pulchella; see Faivovich et al. 2005) tadpoles (Fam. Hylidae) from central eastern Argentina. Fertilized eggs collected from a clean pond near La Plata (Buenos Aires Province) were used for acute and chronic toxicity testing. Assays were done under controlled laboratory conditions. Results of chronic exposure were used to assess the effect of factors such as toxicant concentration and age of organisms at the beginning of exposure on the response variables (growth, development and survival until metamorphosis). Results indicated a higher sensitivity to Cr(VI) of individuals first exposed as tadpoles than those first exposed as embryos during acute and chronic exposure. Exposure to the highest sublethal concentrations (6 to 12 mg 1(-1)) of the toxicant showed early inhibitory effects on growth of all treated organisms compensated at longer exposure periods with an increase in the growth rate compared to the control groups.