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Toad

About: Toad is a research topic. Over the lifetime, 1624 publications have been published within this topic receiving 28732 citations.


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TL;DR: Although the relative sizes of the eight specific organs varied significantly among populations, none organ size was affected by altitude and latitude, and a negative relationship between the relative size of the heart and latitude was found, contrasting to the Hesse’s rule.
Abstract: Phenotypic variation of morphological and physiological traits is assumed to be generated from spatial heterogeneity in environments, and it has been regarded as an important concern domain in evolutionary biology. Organs display markedly size variation among populations along environmental gradients and this variation is associated with changes in oxygen supply and energy demands. Here, we investigated geographical variation in the relative size of organs (i.e., brain, heart, lung, gallbladder, livers, spleen, kidneys, and digestive tract) among 14 populations of Andrew’s toad (Bufo andrewsi) transcending an elevational range from 864 to 2,367 m, and spanning 8° latitude. We found that although the relative sizes of the eight specific organs varied significantly among populations, none organ size was affected by altitude and latitude. However, based on the combined the new data and published data we found a negative relationship between the relative size of the heart and latitude, contrasting to the Hesse’s rule. We also found that the relative size of livers was positively linked to latitude, suggesting that more energy demands and intakes due to slower metabolism in high latitude shaped the evolution of larger livers.

2 citations

06 Dec 2016
TL;DR: This article presents detailed information about two much larger Scandinavian toad populations, both in western Norway, with several thousand individuals, collected from two localities.
Abstract: widespread species with an extensive Euro-Asiatic distribution (note that the taxonomy of B. bufo has recently been revised: Recuero et al., 2012; Arntzen et al., 2013; 2014). Its northern distribution reaches 68° N in Finland (Sinsch et al., 2009) and in Norway, on the Dønna island, almost 66° 15’ N)(Pedersen and Dolmen, 1994). The common toad is, for the most part in and north of the Alps, an explosive breeder, i.e. the animals come together in large numbers at a breeding site for a short breeding period (Wells, 1977; Hartel et al., 2007; for exceptions see Sinsch et al., 2009). Population sizes can vary enormously both on a regional and a temporal scale, from less than 100 up to several thousands of individuals, and by a factor of up to 40 even between successive years (see Sinsch et al., 2009 for an overview). In Scandinavia, published maximum numbers for single populations (i.e. within one breeding locality) so far are in the range of 300–500 individuals. The data are from the Trondheim area (Hemelaar, 1988) and the Bømlo area (Roth, 2011) both in Norway, and the Lund area in Sweden (Loman and Madsen, 1986). The pond in Lund is part of a complex of breeding ponds with a total maximum number of 1054 males and 614 females (Loman and Madsen, 2010). Although the common toad is not a threatened animal in Norway (see Dolmen, 2015) and it is very common for instance on the western coastland (Salvidio et al., 1993), the species has undergone an unexplained decline regionally in south-eastern parts of the country (Semb-Johansson, 1992; Semb-Johansson et al., 2012). In this article we present detailed information about two much larger Scandinavian toad populations, both in western Norway, with several thousand individuals. We have collected data from two localities: the lakes Nesvatnet in the county of Hordaland and Litlevatnet in the county of Møre & Romsdal. Nesvatnet is located near Mundheim (Kvam municipality, province Hordaland; 60.1652°N�� 5.9375°E). The lake is eutrophic with moderate. transparency, about 70000 m2 in area and situated 20 m a.s.l. There exist extensive shallow water areas with dense vegetation dominated by bottle sedge Carex rostrata, bogbean Menyanthes trifoliata and water lilies Nymphaea alba and Nuphar lutea. As part of a typical Norwegian fjord landscape, the lake is located on a peninsula surrounded by suitable terrestrial toad habitats such as natural pine Pinus sylvestris and mixed forest, bogs, heather Calluna vulgaris/Erica spp., and, in more than half of the immediate surroundings, meadows with groups of trees (Nord et al., 2013). The catchment area of the lake is quite large, and Nesvatnet is the only suitable water body for toads in an area of about 15 km2 that is bordered by the sea and by steep rocks to the north rising to 300–400 m a.s.l. In Nesvatnet our data are based mainly on head counting by Torstein Solhøy (TS), SR and KN in 2010–2014. We usually counted once per breeding period on a relatively mild evening after sunset. The lake was covered once either by walking or by rowboat or a combination of both. Male and female toads were counted separately using hand counters. Sex determination was based on size only. In doing so, small females that were not in Herpetology Notes, volume 9: 325-330 (2016) (published online on 06 December 2016)

2 citations

Journal ArticleDOI
TL;DR: The time course of the heat produced by the toad sartorius muscle in response to nerve stimulation was determined by using a new type of heat-sensor with a high time resolution to show the existence of a brief burst of large heat production prior to the onset of the muscle heat associated with contraction.
Abstract: The time course of the heat produced by the toad sartorius muscle in response to nerve stimulation was determined by using a new type of heat-sensor with a high time resolution. The records obtained showed the existence of a brief burst of large heat production prior to the onset of the muscle heat associated with contraction. This initial heat-burst was shown to be produced at the motor endplates. The implications of these findings are discussed.

2 citations

DOI
01 Jan 2007
TL;DR: The collected data document the thermal ecology of Red-spotted toads and contradict previously assumed limits that may not have been experimentally-derived, and may allow informed decision making in land use and conservation efforts by better defining an important ecological parameter in a species that may be subjected to increased pressures by human activity and climatic change.
Abstract: The Thermal Ecology of the Red-spotted Toad, Bufo punctatus, Across Life History by Candice Marie Rausch Dr. Frank van Breukelen, Examination Committee Chair Assistant Professor of Biology University of Nevada, Las Vegas Compared with other terrestrial vertebrates, amphibians are generally less tolerant of thermal extremes. The Mojave Desert has ambient temperatures outside the proposed thermal tolerance zone of its most abundant amphibian, the Red-spotted toad (Bufo (Anaxyrus) punctatus). Few data have been presented regarding the thermal ecology of these animals, including their thermal histories and proposed strategies to avoid temperature extremes. Previous studies suggest B. punctatus avoids extreme thermal exposure and adult toads experience body temperature (T^) below a proposed critical thermal maximum (CT„,^) of 35° C, and can maintain T ̂at 25° C during the winter. Further, previous studies indicate a CT„̂ „̂ for tadpoles of 33° C. A reassessment of the thermal ecology of Red-spotted toads was warranted based on personal observations reported in this thesis. I recorded environmental and/or Ty of Red-spotted toads across their entire life history: eggs, tadpoles, juveniles and adults. In the field, eggs and tadpoles may iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. encounter water temperatures as high as ~40° C. Juveniles can experience Ty as high as 42.2° C. Adult toads experience Ty as high as 39.1° C. These observations were combined with experimental determination of CT„,j,,,across life history statges; the CT„,̂ ,( of tadpoles was variable, but decreased as development progressed; adult toads exhibit a as high as 45.2 ± 1.0° C. I documented thermal preferences (Tp) of tadpoles and adults. In contrast to other studies of the effect of ontogeny on preferred temperature, Tp of Red-spotted toads remains fairly constant across development. I documented developmental time from egg deposition to metamorphosis at 18 days in the summer and 47 days in the spring both periods are less than the previously described 60-day developmental period. Finally, I present preliminary data on apparent basking-like behavior of late stage tadpoles in the field. Despite seemingly high and presumably stressful environmental temperatures. Redspotted toads do not generally live on the verge of thermal tolerance. However, later stage tadpoles may encounter potentially lethal temperatures. The collected data document the thermal ecology of Red-spotted toads and contradict previously assumed limits that may not have been experimentally-derived. These data may allow informed decision making in land use and conservation efforts by better defining an important ecological parameter in a species that may be subjected to increased pressures by human activity and climatic change.

2 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202348
2022118
202112
202012
201913
20188