Rolle der Gesichtswahrnehmungen f�r den Farbwechsel der Fr�sche Rana esculenta L., R. fusca R�sel und Hyla arborea L.

1932 ◽  
Vol 17 (3) ◽  
pp. 574-590 ◽  
Author(s):  
Hans Przibram
Keyword(s):  
Rana Esculenta ◽  
Hyla Arborea

Feeding in anuran communities on islands in the Danube floodplain

2001 ◽  
Vol 22 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Constantin Ciubuc ◽  
Michael Palmer ◽  
Dan Cogălniceanu
Keyword(s):  
Feeding Habits ◽  
Detrended Correspondence Analysis ◽  
Rana Esculenta ◽  
Trophic Niche ◽  
Resource Base ◽  
Size Classes ◽  
Hyla Arborea ◽  
Large Populations ◽  
Bombina Bombina ◽  
Degree Of Overlap

AbstractFeeding habits and food choice of anurans found on two islands in the lower Danube floodplain were studied for two years. The five most abundant anuran species included in this study were Bombina bombina, Hyla arborea, Pelobates fuscus, Rana esculenta and R. ridibunda. In B. bombina the niche breadths of young and adults were of similar magnitude and the degree of overlap between these size classes was high. In Rana esculenta complex young individuals had a much broader trophic niche than adults. A low degree of overlap existed between young and adults, suggesting that the various size classes exploit different segments of the prey resource. Overall, species with a larger size range consumed a higher prey diversity. Prey occurrence was sampled throughout the study on a regular basis. The analysis of selectivity in feeding using Ivlev's index showed that the prey taxa that appeared to be preferred were generally rare in the environment. Detrended Correspondence Analysis revealed that the composition of anuran diets were highly overlapping but differed from the composition of the resource base. The trophic resource was highly partitioned in space and time and thus allowed the coexistence of large populations with similar diets.

A multivariate analysis of amphibian habitat determinants in north western Italy

1990 ◽  
Vol 11 (4) ◽  
pp. 311-324 ◽  
Author(s):  
Ivana Pavignano ◽  
Cristina Giacoma ◽  
Sergio Castellano
Keyword(s):  
Multivariate Analysis ◽  
Statistical Tests ◽  
Ecological Factors ◽  
Water Hardness ◽  
Breeding Population ◽  
Rana Esculenta ◽  
Bufo Bufo ◽  
Multivariate Statistical ◽  
Habitat Features ◽  
Hyla Arborea

AbstractThe distribution of Bufo bufo, Rana esculenta complex, Rana dalmatina, Hyla arborea, Triturus carnifex and Triturus vulgaris were studied in 61 ponds in NW Italy, in relation to a number of specific habitat features. Multivariate analysis identifies those habitat parameters which classify ponds into characteristic habitat groups. Several multivariate statistical tests were carried out to identify habitat features characteristic of each species and to delineate ecological factors that influence amphibian distributions and size of breeding populations. Variables scored at each pond were: extent of aquatic vegetational cover, age of the pond, terrestrial habitats occurring near the ponds, degree of human interference, surface areas, maximum depth, chemical water factors (such as pH and water hardness). The first four of these parameters influenced breeding population presence of R. dalmatina, H. arborea, T. vulgaris and T. cristatus significantly. Densities of H. arborea, R. dalmatina, B. bufo and R. esculenta were apparently unaffected by any of these parameters; these species seem to colonize available habitats almost at random.

THE GAMETOKINETIC ACTIVITY OF SEROTONIN IN THE MALE OF RANA ESCULENTA

1962 ◽  
Vol 40 (3_Suppl) ◽  
pp. S146 ◽  
Author(s):  
B. Salvadori ◽  
G. Cagnazzo ◽  
G. Bernardini
Keyword(s):  
Rana Esculenta

Optical Spectra of Melanin Films Extracted from Rana esculenta L.

2005 ◽  
pp. 89 ◽  
Author(s):  
G. Perna ◽  
A. Gallone ◽  
V. Capozzi ◽  
P. F. Biagi ◽  
A. Fratello ◽  
...  
Keyword(s):  
Rana Esculenta ◽  
Optical Spectra

Opioids and testicular activity in the frog, Rana esculenta

1993 ◽  
Vol 137 (1) ◽  
pp. 49-NP ◽  
Author(s):  
F. Facchinetti ◽  
A. R. Genazzani ◽  
M. Vallarino ◽  
M. Pestarino ◽  
A. Polzonetti-Magni ◽  
...  
Keyword(s):  
Physiological Activity ◽  
Mammalian Species ◽  
Rana Esculenta ◽  
Cell Degeneration ◽  
Efferent System ◽  
Naltrexone Treatment ◽  
Nucleus Infundibularis ◽  
The Brain

ABSTRACT The presence and activity of brain, pituitary and testicular β-endorphin (β-EP)-like material have been studied in the frog, Rana esculenta, using reverse-phase high-pressure liquid chromatography, coupled with radioimmunoassay and immunocytochemistry. In-vivo and in-vitro treatments with naltrexone were carried out to assess the putative physiological activity of opioid peptides. β(1–31) and (1–27), together with their acetylated forms, have been identified in brain, pituitary and testis. In particular, β-EP(1–31) concentrations peaked during July in the brain and pituitary, whilst in testes maximum concentrations were found in April and November. β-EP immunoreactivity was present in the brain within the nucleus preopticus and nucleus infundibularis ventralis while positive fibres in the retrochiasmatic regions projected to the median eminence. In the testis, interstitial cells, canaliculi of the efferent system, spermatogonia and spermatocytes showed positive immunostaining for β-EP. In intact animals, naltrexone treatment increased plasma and testicular androgen levels and this effect was confirmed in in-vitro incubations of minced testes. Naltrexone also induced a significant increase in germ cell degeneration. Our results indicated that an opioid system modulates the hypothalamus-pituitary-gonadal axis in the frog, Rana esculenta and, for the first time, we have shown that the testicular activity of a non-mammalian species may be regulated by opiates locally. Journal of Endocrinology (1993) 137, 49–57

Hormonal control of in vitro vitellogenin synthesis in Rana esculenta liver: Effects of mammalian and amphibian growth hormone

1992 ◽  
Vol 88 (3) ◽  
pp. 406-414 ◽  
Author(s):  
Oliana Carnevali ◽  
Gilberto Mosgoni ◽  
Kazutoshi Yamamoto ◽  
Tetsuya Kobayashi ◽  
Sakae Kikuyama ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Rana Esculenta ◽  
Hormonal Control ◽  
Vitellogenin Synthesis
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