1,727,882 research outputs found
Conservation genetics of an island toad: Bufo bufo in Jersey
Full text linkOn Jersey (British Channel Islands), common toads often reproduce in small, urban ponds. This atypical breeding strategy has implications for their persistence and they have declined on the island in recent times. We used polymorphic microsatellite markers to compare genetic diversity in Bufo bufo from five different ponds in Jersey with two populations from north-west France. Genetic diversity of Jersey toads was comparable with that of populations elsewhere in Europe. Numbers of breeding female toads in Jersey were correlated with pond area but estimators of genetic diversity were unrelated to pond area or female numbers. Fst estimates and isolation by distance tests indicated that there is little gene flow between breeding sites on the island. Jersey populations last shared a common ancestor with those of north-west France long before the island's physical separation about 6000 years ago. Toads have a long history in Jersey and were once probably very numerous there. The average effective historical population size of Jersey toads is estimated to be 15,000-16,000. Although genetic diversity of Jersey B. bufo is currently quite high, recent developments on the island may threaten this situation in the near future
Antimicrobial activity of skin secretions isolated from Indian toad, Bufo melanostictus Schneider 1799
Full text linkAmphibians like toads have been known to secrete antimicrobial secretions outside their body into their environments, through skin pores and parotid glands. Toad skin-secretions contain four types of compounds namely, biogenic amines, bufadienolides, alkaloids & steroids and peptides & proteins. Bulk of research relating to amphibian antimicrobial secretions has been done on frogs. In toads, such research has only been done in South America, Europe and China. Antimicrobial secretions vary considerably from specie-to-specie and drastically across various biomes. This prompted us to examine and confirm presence of antimicrobial activity (if any) in Indian Common Toad (Bufo melanostictus Schneider 1799) skin secretions since; no such analysis had been previously done on this toad which is found all across the South-east Asia. The antibacterial potency of toad skin secretions was tested against the bacteria, Escherichia coli. After running preliminary antibacterial analysis assays, we found that these cutaneous secretions retrieved from Indian Common Toad possessed potential bactericidal activity. The results that we got confirmed that some unexplored bactericidal components were present in skin secretions of these toads. These conclusions call for further research into biochemistry and molecular characterization of these components
Post-Meiotic Intra-Testicular Sperm Senescence in a Wild Vertebrate
No full textThere is growing interest in sperm senescence, both in its underlying mechanisms and evolutionary consequences, because
it can impact the evolution of numerous life history traits. Previous studies have documented various types of sperm
senescence, but evidence of post-meiotic intra-testicular sperm senescence in wild animals is lacking. To assess such
senescence, we studied within-season changes in sperm motility in the common toad (Bufo bufo), where males produce all
sperm prior to the breeding season. We found that males exposed to experimentally induced re-hibernation at the start of
the breeding season, that is to experimentally lowered metabolic rates, stored sperm of significantly higher motility than
males that were kept under seminatural conditions without females throughout the breeding season. This finding indicates
that re-hibernation slows normal rates of sperm ageing and constitutes the first evidence to our knowledge of post-meiotic
intra-testicular sperm senescence in a wild vertebrate. We also found that in males kept in seminatural conditions, sperm
motility was positively related to the number of matings a male achieved. Thus, our results suggest that post-meiotic intratesticular
sperm senescence does not have a genetically fixed rate and may be modulated by temperature and possibly by
mating opportunities
Anomalías oculares en híbridos <i>Bufo paranecmis</i> ♂ x <i>Bufo arenarum</i> ♀ (Anura: bufonidae)
No full textThe hybrids between Bufo paracnemis ♂ x Bufo arenarum ♀ are counted among tbe so called "vital hybrids". Our resu1ts have revealed relevant ocular anomalies in 90% of cases. In some larvae the lens is lacking in either one or both eyes (20%); in others the lens it is found in an opposite position to normal (25%) or else one normal and one different eye is formed (20%).
Histological analysis reveals anomalies in the retinal area, observing flexuous movements in the pigmentary strata (5%). Eyes folded over themselves were also observed (5%). The most severe alterations produced cases of anophtalmia (10%). On occasions (5%), groupings of pigments were found instead of the eyes. l00% of the larvae were normal. The other organs show analogies to those of the larvae of Bufo paracnemis, including the dorsal pattem.Asociación Herpetológica Argentina (AHA
The food spectrum analysis of Rana temporaria and Bufo bufo in anthropogenically transformed habitats of the Ukrainian Roztochchia
No full textAs a result of the research, 109 individuals of two amphibian species: the common frog (Rana temporaria) and the common toad (Bufo bufo) were selected. These two species are the most numerous among other species of amphibians within the studied territory, therefore, they can be considered typical species in the anthropogenically transformed habitats of the Ukrainian Roztochchia. During the analysis of the collected material, Ivlev’s selectivity index was used to determine the selective attitude of the studied amphibian species to the number of consumed objects. Comparing data obtained from Barber’s traps and material extracted from the stomachs of amphibians, it was concluded that depending on the habitat type, both the common frog (Rana temporaria) and the common toad (Bufo bufo) show a certain feeding selectivity. The common toad consumes mostly the representatives of Annelida (15%), Arachnida (15%) and Coleoptera (18%), what makes up 48% of all consumed objects in total. The common frog, under the conditions of anthropogenically transformed environment, prefers Mollusca (15%), Myriapoda (20%) and Hemiptera (20%) mostly, what is 55% in total. In half of the stomachs we examined for, both amphibian species, plant residues were found, specifically parts of leaves and branches. Additionally, in individuals of the Bufo bufo species, stones were discovered in the stomach. Most likely, these items ended up there accidentally during the capture of primary food objects. Species of tailless amphibians are highly vulnerable to the negative impact of various anthropogenic factors. Deforestation, water bodies drainage, and global or local environmental pollution can significantly affect diverse ecosystems. This, in turn, may lead to the disappearance of segments of the dietary spectrum for amphibians. Monitoring the trophic interactions of this animal class is crucial, given the importance of amphibians as vital links in food chains. This factor underscores the need for periodic trophic monitoring, as amphibians play a pivotal role in sustaining ecological balance within their vulnerable populations
Cambios de asignación genérica en especies fósiles del este de Europa descritas como Bufo belogoricus Ratnikov, 1993, Bufo planus Ratnikov, 1993 y Bufo albus Ratnikov, 1993 (Amphibia, Anura, Bufonidae)
Full text linkThe generic assignment of three fossil forms described as Bufo belogoricus Ratnikov, 1993, Bufo planus Ratnikov, 1993 and Bufo albus Ratnikov, 1993 is discussed. The author justifies why their original generic names should not be changed to Pseudepidalea, as recently proposed, but should be maintained until more convincing evidence is discovered.Se discute la atribución genérica de tres formas fósiles descritas como Bufo belogoricus Ratnikov, 1993, Bufo planus Ratnikov, 1993, y Bufo albus Ratnikov, 1993. El autor justifica las razones por las cuales las adscripciones genéricas originales no deberían cambiarse a Pseudepidalea, como recientemente se ha propuesto, sino mantenerse hasta que se descubra nueva evidencia más convincente
Внутривидовая изменчивость серой жабы Bufo bufo.
Full text linkВ статье рассмотрены вопросы внутривидовой изменчивости популяций серой жабы. Установ-лена специфичность морфометрической структуры Bufo bufo,обитающей в Брестской, Витебской, Гомельской, Гродненской и Могилевской областях Республики Беларусь. Полученные данные свидетельствуют о ландшафтно-экологической определенности формирования внутривидовой изменчивости серой жабы, имеющей как общие, так и видоспецифичные черты. = In article questions of intraspecific variability of populations of a grey toad are considered. Specificity morfometric structures Bufo bufo living in Brest, Vitebsk, Gomel, Grodno and Mogilyov areas of Byelorussia is established. The received data testify to landscape-ecological definiteness of formation of intraspecific variability of the grey toadhaving as general, and specific features
Proteins of parotoid gland secretions from toads of the genus Bufo
No full textFreeze-dried parotoid gland secretions from toads of the genus Bufo contained large proportions of protein (25-35% by weight). SDS-PAGE suggested that secretions from several species of Bufo contained mixtures of proteins in the relative molecular mass range of approximately 12 - 200 kDa, which exhibited markedly different banding patterns from species to species. These proteins were presumably not discovered before because the previous extraction procedures used with these secretions were designed to examine low molecular mass compounds and would denature the proteins. SDS-PAGE of secretions from B. mauritanicus and B. calamita are shown here. The N-terminal amino acid sequence of one of the bands (approx. 58 kDa) of B. mauritanicus was found to be LPIPAFPGLDHGF and of a B. calamita band (30.5 kDa) was VQVFGLQKEA. No significant similarities to these two sequences and to three separate but partial N-terminal sequences obtained from these species were found in genetic databases
Morphological comparison of Bufo Bufo and Bufo verrucosissimus species in Turkey
No full textBu tez çalışmasının amacı Türkiye'de dağılım gösteren Bufo cinsine ait olan Bufo bufo (Linneaus, 1758) ve Bufo verrucosissimus (Pallas, 1814) türleri arasındaki morfolojik farklılıkların belirlenmesidir. Çalışma kapsamında, Türkiye genelinde 25 farklı ilden örnekleme yapılmıştır. Örneklenen 193 (96 +, 97 >) bireyden 36 farklı değişene ait morfolojik ölçümler alınarak bireyler hem cinsiyet hem de tür bazında istatistiksel olarak karşılaştırılmıştır. Çalışmadan elde edilen bulgularda, dişi bireylerin erkeklere nazaran daha büyük vücut yapısına, büyük bir başa, dar açılı ve divergent durumlu parotidler ile başın her iki yanında daha fazla sıklıkta keratinli siğillere sahip olduğu belirlenmiştir. Ayrıca, Bufo verrucosissimus türüne ait erkek ve dişi bireylerin Bufo bufo türüne ait erkek ve dişi bireylerden daha büyük bir baş yapısına ve daha uzun iç metatarsal tüberküllere sahip olduğu belirlenmiştir. Parotid açıları, parotidlerin durumu ve keratinli siğiller bakımından ise herhangi bir farklılık bulunmamıştır. Sonuç olarak yapılan bu çalışmada türlerin morfolojik olarak çoğu karakter bakımından benzer olduğu, türler arasında yalnızca baş yapısı ve iç metatarsal tüberkül bakımından farklılıklar bulunduğu tespit edilmiştir. In this thesis, it is aimed to determine morphological differences between Bufo bufo (Linneaus, 1758) and Bufo verrucosissimus (Pallas, 1814) species belonging to the genus Bufo. Within the context of this study, 193 (96 +, 97 >) individuals were sampled from 25 different provinces. These individuals were measured in terms of 36 different morphological characters and compared statistically between sexes and species. According to findings, it was found that females are bigger than males in terms of head and general body structure, their parotoids are more divergent and have narrower angle and more keratinized spines on the both sides of head. Besides, it was found that the individuals, in both sexes, of Bufo verrucosissimus have a bigger head and longer inner metatarsal tubercles than the individuals of Bufo bufo. There was no difference between species in terms of parotoid angle, parotoid divergence and keratinized spines. As a result of this study, it was found that both species are morphologically similar and differences between species are related to the head structure and inner metatarsal tubercle
C-banding karyotypes and location of NOR's in the toad species Bufo bufo and Bufo viridis from Yugoslavia
No full textThe karyotypes, C-banding patterns and positions of nucleolus organizer regions (NORs) of two European species of toads, Bufo bufo and Bufo viridis from seven localities in Yugoslavia were investigated. These karyotypes and chromosomal markers were compared with those in other species and subspecies of the Bufo bufo complex. The results suggest that C-banded patterns are characters specific for those species. A marker band on chromosome 5 in the karyotype of B. bufo bufo is shown.Ispitivani su kariotipovi, C-trake i položaj nukleolusnih organizatora (NOR) dve evropske vrste žaba, Bufo bufo i Bufo viridis, sa 7 jugoslovenskih lokaliteta. Kariotipski i hromozomalni markeri ovih vrsta poređeni su sa podacima koji se odnose na druge vrste i podvrste. Rezultati ukazuju da je raspored C-traka specifične za ispitivane vrste. Kod vrste B. bufo bufo nađena je marker traka na petom hromozomu.Projekat ministarstva br. 03E0
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