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1.
Hoffmann H 《Revista de biología tropical》2005,53(3-4):561-568
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Cytogenetic analyses were done on specimens of Hyla marginata and on three populations of H. semiguttata differing in morphology and in the physical parameters of their advertisement call, as well as in individuals of Hyla sp. (aff. semiguttata). All specimens had 2n=24 chromosomes with a morphology very similar to that of other 24-chromosome Hyla species. Hyla semiguttata and H. marginata showed the same C-banding pattern but were distinguished by the location of the NOR on pair 1 in H. semiguttata (in the three populations) and Hyla sp. (aff. semiguttata), and on pair 10 in H. marginata. The H. semiguttata populations did not differ cytogenetically, despite variations in their morphology and advertisement calls. Similarly, H. semiguttata and H. p. joaquini studied previously had identical C-banding patterns and NOR locations, suggesting that they are very closely related. 相似文献
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Faivovich J García PC Ananias F Lanari L Basso NG Wheeler WC 《Molecular phylogenetics and evolution》2004,32(3):938-950
A molecular phylogenetic analysis of the Hyla pulchella species group was performed to test its monophyly, explore the interrelationships of its species, and evaluate the validity of the taxa that were considered subspecies of H. pulchella. Approximately 2.8 kb from the mitochondrial genes 12s, tRNA valine, 16s, and Cytochrome b were sequenced. The analysis included 50 terminals representing 10 of the 14-15 species currently recognized in the H. pulchella group, including samples from several localities for some taxa, several outgroups, as well as two species previously suspected to be related with the group (Hyla guentheri and Hyla bischoffi). The results show that the H. pulchella and Hyla circumdata groups are distantly related, and, therefore, should be recognized as separate groups. As currently defined, the H. pulchella group is paraphyletic with respect to the Hyla polytaenia group; therefore, we recognize the Hyla polytaenia clade in the H. pulchella group. Two subspecies of H. pulchella recognized by some authors are considered full species including Hyla pulchella riojana because it is only distantly related to H. pulchella, and Hyla pulchella cordobae because molecular and non-molecular evidence suggests that it is specifically distinct. With the inclusion of the H. polytaenia clade, H. guentheri, and H. bischoffi, and the recognition of the two former subspecies of H. pulchella as distinct species, the H. pulchella group now comprises 25 described species. All representatives of the H. pulchella group with an Andean distribution are monophyletic and nested within a clade from the Atlantic forest from south-southeastern Brazil/northeastern Argentina, and Cerrado gallery forest from central Brazil. 相似文献
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One of the major unanswered questions in the study of global amphibian declines is why only some species or populations suffer declines. A possible explanation is that species and populations vary in the genetic basis of their tolerance to environmental stress such as chemical contamination. The presence of genetic variation in tolerance to chemicals and in fitness traits of amphibians is essential for persistence of species populations through survival and successful reproduction in contaminated environments. We tested for the presence of genetic variation in the tolerance of amphibian larvae to the insecticide carbaryl using gray treefrog tadpoles (Hyla versicolor). We also assessed whether tolerance of tadpoles is negatively associated with larval performance traits directly related to adult fitness, thereby providing a test of the "cost of tolerance" hypothesis. Our results demonstrate significant variation in tolerance of tadpoles to the insecticide carbaryl within a single population of the gray treefrog, Hyla versicolor. Our half-sibship design indicates that variation among sires explains a significant amount of the variation in chemical tolerance thereby suggesting a heritability genetic basis. Our results also indicate the presence of a fitness tradeoff with tolerance to the chemical carbaryl being negatively correlated, or traded off, with survival of tadpoles reared in the field in the absence of the chemical. Knowledge of genetic tradeoffs with chemical tolerance under realistic environmental conditions will be important for predicting the rate of adaptation and potential for persistence of species. Finally, the partitioning of environmental and genetic variation in tolerance to chemicals is critical to identifying which species are most susceptible, the amount of genetic variance present, the potential for adaptation to contaminants, and the presence of fitness tradeoffs. Such information is necessary to clearly understand the persistence of populations, and ultimately, the processes leading to species declines. 相似文献
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Michael S. Blouin 《Journal of morphology》1991,209(3):305-310
Hyla cinerea and H. gratiosa are closely related treefrogs that differ at metamorphosis in the length of the hind limb relative to snout vent length. A developmental series of larvae of the two species raised under uniform laboratory conditions reveals that H. cinerea have proportionately longer legs at metamorphosis than H. gratiosa for the following reasons: 1) Hyla cinerea initiate limb growth at a smaller body size than H. gratiosa, 2) H. cinerea have a faster rate of limb growth, and 3) body growth rates in H. cinerea and H. gratiosa are nearly identical until just before metamorphosis. 相似文献
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H. D. Rosa M. Elisa Oliveira 《Journal of Zoological Systematics and Evolutionary Research》1994,32(2):117-128
Genetic differentiation of Hyla arborea molleri and H. meridionalis was studied through allozyme electrophoresis and through essays of artificial hybridization. Samples were taken at several localities in Portugal, where these species occur either in sympatry or allopatry, and at one locality in France. Of the 21 presumptive loci analyzed, 6 were monoallelic, while 9 loci were discriminative between both species. A relatively high level of genetic differentiation was found between the two species (NEI's D = 0.725), contrasting with their morphological similarity. Remarkably low levels of genetic variability were found within species, with greater differentiation found among samples of H. meridionalis than of H. a. molleri. Although the capacity for interspecific hybridization was low, hybrid embryos resulted from both reciprocal crosses, but with much greater success in the cross ♂H. a. molleri x δH. meridionalis. Hybrids showed greater similarity with the male parent, and showed heterozygote allozymic phenotypes for discriminative loci. Results are compared with those of similar studies on the same and different species of Hyla, and differentiation of H. a. molleri and H. meridionalis is discussed in relation to their taxonomic status and origin. 相似文献
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C R Blem C A Ragan L S Scott 《Comparative biochemistry and physiology. A, Comparative physiology》1986,85(3):563-570
Metabolic rates, temperature acclimation, lipid deposition and temperature tolerance were investigated in two species of hylid treefrogs, the green treefrog (Hyla cinerea) and the coastal plain (Cope's) gray treefrog (Hyla chrysoscelis). The rate of oxygen consumption at rest differed between the two species only at 30 degrees C; there was no difference in respiratory metabolism at lower ambient temperatures. Hyla cinerea generally completed metabolic acclimation earlier than H. chrysoscelis, particularly at high temperatures; both species appeared to be fully acclimated in 6 days or less. The gray treefrog is less tolerant of high ambient temperatures than the green treefrog; mean upper lethal temperature was 41.5 degrees C for Hyla chrysoscelis and 43.7 degrees C for H. cinerea. Metabolized energy was higher at high ambient temperatures (i.e. 29 degrees C) for H. chrysoscelis than H. cinerea, while the reverse was true at 19 degrees C. The coefficient of utilization (100 X metabolized energy/gross energy intake) did not vary significantly between species or within species over the ambient temperature range of 19-24 degrees C; H. chrysoscelis had a significantly higher efficiency at 29 degrees C. Lipid reserves were generally similar in the two species throughout the summer. Differences in behavior, seasonal variation in activity and timing of reproduction are all related to thermal physiology and may play a role in determining the distributional limits of the two species. 相似文献
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Peter Weygoldt Oswaldo Luiz Peixoto 《Studies on Neotropical Fauna and Environment》2013,48(4):237-247
Hyla ruschii n.sp., a small frog tentatively included into the "Hyla parviceps group”;, is described from the Atlantic Mountain Domain around Santa Teresa, State of Espirito Santo, Brasil. 相似文献
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Summary Multivariate analyses of 18 morphological variables recorded for amplectant males and females and non-amplectant males of Hyla marmorata and Triprion petasatus reveal that in both of these explosive breeding species, mating is significantly non-random. Females of H. marmorata from the relatively aseasonal environment of the Upper Amazon Basin average larger than males, and amplectant males average larger than non-amplectant males. Females of Triprion petasatus from the seasonal environment of the Yucatan Peninsula average larger than males, the sizes of males are significantly correlated with the sizes of the females with which they are paired in amplexus, and amplectant males have shorter internarial distances than non-amplectant males. For both species, non-random mating is interpretable in terms of sexual selection, but the relative importance of male-male competition and female choice cannot be assessed. 相似文献
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The chondrocranium and cranial muscles of Lysapsus limellum, Pseudis cardosoi, P. minuta and four subspecies of P. paradoxa (caribensis, occidentalis, paradoxa and platensis) are described. Lysapsus and Pseudis are related to the Hylidae by: (1) vertical processus anterolateralis of the larval crista parotica, and (2) presence of m. mandibulolabialis inferior and superior (the latter reversed in P. cardosoi). We confirm some larval synapomorphies previously proposed for the pseudids, except the m. subarcualis obliquus II having one head and the absence of copula anterior. We add three new features for the pseudids: (1) the distal end of ceratobranchiales III and IV projects towards either the capsula auditiva (Lysapsus) or the processus basicapsularis – new term – (Pseudis); (2) the arcus subocularis is twice as wide at the level of the processus ascendens as it is just posterior to the processus muscularis quadrati, and (3) the lateral corner of the processus articularis quadrati largely projects laterally. We diagnose Lysapsus larvae (the states of Pseudis in parentheses) as follows: (1) short processus pseudopterygoideus (long), (2) absence of lateral development of larval crista parotica (presence), (3) absence of commissura proximalis II (presence), (4) presence of processus lateralis hyalis – new term – (absence), (5) absence of processus basicapsularis (presence), (6) processus ascendens slightly curved along its entire extent (curved at the union with the basi cranii only), and (7) absence of m. tympanopharyngeus (presence). 相似文献
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ROBERT F. INGER 《Zoological Journal of the Linnean Society》1992,105(2):225-237
Six larval forms of the bufonid genus Ansonia from Borneo share the following synapomorphies: cup-like, ventral oral disc; an expanded post-dental portion of the lower lip, which has a papillate margin; upper keratinized jaw sheath divided; body markedly flattened ventrally; eyes set relatively far back on the body. All of these tadpoles live on the bottom in strong currents, except for larval Ansonia leptopus , which lives in drifts of dead leaves that accumulate in eddies within streams. These larval forms differ among themselves in body shape, development of inframarginal papillae on the lower lip, size of the gap between the keratinized parts of the upper jaw sheath, width of the post-dental portion of the lower lip, relative lengths of upper and lower rows of labial teeth, and arrangement of the gut coils. One form has an abdominal sucker. Changes in these characters are not correlated; the derived condition in one character is not always associated with the derived state in another. Consequently, these tadpoles cannot be arranged in a simple morphocline from least to most derived, again with the exception of A. leptopus , which is the least modified in all respects. Although tadpoles of Ansonia resemble those of the neotropical bufonid genus Atelopus in general specialization for benthic life in flowing water, they differ from that group in body form and details of the oral disc. 相似文献
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Matthew D. Venesky Richard J. Wassersug Michael E. Jorgensen Mellie Riddle Matthew J. Parris 《Zoomorphology》2011,130(1):31-38
Several studies have explored various components of feeding kinematics in anuran larvae; however, a direct comparison of feeding
kinematics among morphologically similar and sympatric taxa has not been undertaken. We used high-speed videography (500 frames/s)
to capture feeding kinematics of Anaxyrus fowleri (Hinckley, 1882) (Fowler’s Toad), Hyla chrysoscelis (Cope, 1880) (Grey Treefrog), Scaphiopus holbrookii (Harlan, 1835) (Eastern Spadefoot Toad), and Lithobates sphenocephalus (Cope, 1889) (Southern Leopard Frog) tadpoles as they foraged from an algal-covered substrate. In total, we filmed 120 feeding
sequences from 25 feeding bouts and quantified eight kinematic variables that were common among all four species. Despite
relatively similar keratinized feeding structures among taxa, our videography data revealed fundamental differences in how
the tadpoles used these structures. One specific difference was in the speed of the gape cycle. Among taxa, S. holbrookii tadpoles had the longest gape cycle and longest time to reach maximum gape, whereas A. fowleri and L. sphenocephalus tadpoles had shorter durations for both variables and did not differ between species. We also found species differences in
the magnitude that tadpoles narrow their lower jaw sheath. Irrespective of gape size, the lower jaw sheath of S. holbrookii tadpoles narrowed by approximately 26% of its maximum width—a twofold difference from A. fowleri tadpoles, which narrowed only 13%. Our study revealed that tadpoles with similar oral structures feeding on the same substrate
can exhibit major differences in feeding kinematics. 相似文献
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Specimens of Hyla nana and Hyla sanborni from a syntopic population were studied cytogenetically. These species are morphologically very similar and are frequently misidentified, confused with each other. Both species had a diploid chromosome number, 2n = 30. However, the karyotypes of H. nana and H. sanborni differed considerably from each other in the number of submetacentric and telocentric chromosomes. The two species also differed in their primary NOR-bearing chromosomes (metacentric pair 13 in H. nana and telocentric pair 12 in H. sanborni). Additional nucleolus organizer regions (NORs) were detected by Ag-NOR staining and FISH in chromosome pairs 1, 5, 6, 12, and 14 in seven specimens of H. nana. Thus, a total of six patterns of NOR were identified. These differences in karyotype and in NOR location allowed the unambiguous identification of syntopic individuals of the two species. However, the chromosomal morphology of both species differed from that reported for populations from other geographic regions, suggesting that a systematic reevaluation of this group of Hyla may be necessary. 相似文献
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This study was carried out to assess the localization of hyaluronic acid (HA) and the distribution of glycoproteins in the gastrointestinal system of adult Hyla orientalis. Histochemical analysis of the gastrointestinal system in H. orientalis showed that mucous content included glycogene and/or oxidable dioles [periodic acid/Schiff (PAS)+], neutral or acid-rich (PAS/AB pH 2.5+), sialic acid residues (KOH/PAS+) and acid sulphate [Aldehyde fuchsin (AF)+] glycoproteins. However the mucus content was not the same in stomach, small and large intestine. The mucus content of stomach included only glycogene and/or oxidable dioles and sialic acid residues. Besides these histochemical methods, the localization of HA was detected using biotinylated hyaluronic acid binding protein labeled with streptavidin-fluorescein isothiocyanate (FITC). In the extracellular matrix of the submucosa, the reaction for HA was evident. Since HA was located in submucosa beneath the epithelial layer of gastrointestinal system, it has a significant role in hydric balance, and essential to provide the gastrointestinal system integrity and functionality. According to biometric results, there were statistical differences between small and large intestine in terms of the amount of material stained positive with PAS/AB, PAS, KOH/PAS and AF/AB. Additionally, number of goblet cells in the small and large intestine was significantly different.Key words: Gastrointestinal system, goblet cell, glycoproteins, hyaluronic acid, amphibian, Hyla. 相似文献
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Sanchis Ivan Spinelli Roque Aschemacher Nicolas Humpola Ma. Veronica Siano Alvaro 《Amino acids》2020,52(3):387-396
Amino Acids - Alzheimer’s disease (AD), the most common form of dementia, is a growing problem worldwide, with 10 million incident cases registered every year. The complex etiology of AD has... 相似文献