Can age and growth patterns explain the geographical variation in the body size of two toad species?

Determining both the age structure and growth pattern allows to establish the causal factors, environmental and/or genetic, that eventually may be responsible for the observed pattern of divergence. We examined the variation in age structure and growth pattern across populations of two toad species, Pelobates cultripes and Epidalea calamita that exhibit a geographic variation in body size in southern Spain. For both species, populations differed in mean age but age structure did not correlate with body size variation across populations. Although the population with the youngest females found for E. calamita was the smallest in body size, the oldest males for both species were found in a small body size population. The growth pattern fit well to a von Bertalanffy growth model and interdemic divergence were found for both the asymptotic body size (Sm ) and the growth coefficients (k). As expected, Large-Bodied populations of both species attained higher Sm but, Small-Bodied population had higher, although non significantly different, k growth coefficients. Also, the Small-Bodied population attained sexual maturity sooner but had also high longevity. The observed pattern may reflect both environmental variations in resources availability affecting body size observed across populations, but also different growth and maturity pathways that may respond to contrasting selective pressures.Fil: Marangoni, Federico. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Tejedo, Miguel. Consejo Superior de Investigaciones Científicas; EspañaFil: Cogalniceanu, Dan. Universitatea Ovidius din Constanta; Rumani

The advertisement call of Pristimantis subsigillatus (Anura, Craugastoridae)

We describe for the first time the advertisement call of Pristimantis subsigillatus from southern Ecuador. Our study provides a detailed quantitative characterization of the advertisement call of P. subsigillatus, filling a gap in our knowledge of this genus, the most speciose among vertebrates. Males called perched on vegetation 0.5-2.5 m above ground, always during mild rain. The advertisement call is composed of a single note with a duration of 63-80 ms, with an initial short pulse (3-10 ms) followed by a longer tonal component. Call rates ranged between 4-12 calls/min. The dominant frequency varied between 2.02-2.82 kHz

Small-scale spatial and temporal variation of life-history traits of common frogs (Rana temporaria) in sub-Arctic Finland

Small-scale spatial and temporal variation in abiotic and biotic environmental conditions can lead to large differences in mean values of important life-history traits in ectothermic vertebrates, such as amphibians. However, relatively little is known about small-scale variation in life-history traits of sub-Arctic amphibians. We studied the spatio-temporal variation of adult life-history traits linked to age and body size in the common frog (Rana temporaria) from low (i.e., valley at 480 m a.s.l.) and high (i.e., hill at 530-650 m a.s.l.) altitude sites in the sub-Arctic Kilpisjarvi area (Finland). Data on life-history traits of frogs from hill sites collected during a 3-year field study were compared with previously published data from the valley sites. The results showed spatio-temporal variation in life-history traits, frogs responding to spatio-temporal variation in the environmental conditions with variation in age, life span, survival rates, body size, and mass. Frogs from hill sites had shorter life span, both in terms of meanPeer reviewe

Reassessment of red list status of european amphibians

Peer reviewe

An extended mtDNA phylogeography for the alpine newt illuminates the provenance of introduced populations

Many herpetofauna species have been introduced outside of their native range. MtDNA barcoding is regularly used to determine the provenance of such populations. The alpine newt has been introduced across the Netherlands, the United Kingdom and Ireland. However, geographical mtDNA structure across the natural range of the alpine newt is still incompletely understood and certain regions are severely undersampled. We collect mtDNA sequence data of over seven hundred individuals, from both the native and the introduced range. The main new insights from our extended mtDNA phylogeography are that 1) haplotypes from Spain do not form a reciprocally monophyletic clade, but are nested inside the mtDNA clade that covers western and eastern Europe; and 2) haplotypes from the northwest Balkans form a monophyletic clade together with those from the Southern Carpathians and Apuseni Mountains. We also home in on the regions where the distinct mtDNA clades meet in nature. We show that four out of the seven distinct mtDNA clades that comprise the alpine newt are implicated in the introductions in the Netherlands, United Kingdom and Ireland. In several introduced localities, two distinct mtDNA clades co-occur. As these mtDNA clades presumably represent cryptic species, we urge that the extent of genetic admixture between them is assessed from genome-wide nuclear DNA markers. We mobilized a large number of citizen scientists in this project to support the collection of DNA samples by skin swabbing and underscore the effectiveness of this sampling technique for mtDNA barcoding

Breed fast, die young: demography of a poorly known fossorial frog from the xeric Neotropics

We successfully used skeletochronology to provide the first detailed demographic data regarding Ceratophrys stolzmanni, a cryptic, fossorial amphibian inhabiting the xeric Neotropics. We observed a female-biased sexual size dimorphism, but no differences in age parameters between the two sexes. Growth rate is accelerated during the first year of life, both before and after metamorphosis, followed by a rapid sexual maturation and a short lifespan. Both males and females reached sexual maturity before they were one year old, the mean age was two years, and longevity was low for both sexes, with only 2% of the tested individuals, all females, reaching the age of four years. We discuss the implications of the observed aging and growth patterns for the long-term survival and conservation of the species, comparing our results to other tropical species

Pond drying cues and their effects on growth and metamorphosis in a fast developing amphibian

The hydroperiod of breeding habitats imposes a strong selection on amphibians and pond-breeding species usually exhibit a high degree of plasticity in the duration of larval period. However, the potential for phenotypic plasticity in fast developing species was investigated only in a small number of anurans, and the specific response to environmental cues such as low water versus decreasing water level, as well as the effects of such cues on particular developmental stages, are even less understood. In this context, we investigated the plastic response to pond desiccation in a neotropical species (Ceratophrys stolzmanni) by raising tadpoles in three water level treatments: constant high, constant low and decreasing. The growth rates were the highest reported for amphibian tadpoles (up to 0.3g/day) and the time to metamorphosis was short in all treatments, with the fastest developing tadpole metamorphosing in only 16 days after egg deposition. Individuals from the constant high water level treatment had a higher growth rate than those in the other two treatments, whereas decreasing and constant low water levels had similar effects on development, speeding up metamorphosis. In turn, this involved a cost as these tadpoles had a lower body size and mass at metamorphosis than the ones raised in constant high water levels. The final stages of metamorphosis, when tadpoles are the most vulnerable, were shorter in tadpoles exposed to a decreasing water level, allowing them to leave water quickly. Our experiment demonstrates that phenotypic plasticity is maintained even in environments devoid of permanent aquatic habitats. Ceratophryd tadpoles are able to shorten their developmental time when they perceive a risk of desiccation and react similarly to cues coming from the two unfavorable water conditions showing their adaptation to ephemeral and unpredictable breeding habitats