| effects of frog-skin angiotensin ii in amphibians. | the role of frog-skin angiotensin ii (aii) in amphibia was studied by comparing the sodium and water permeability effects of three angiotensins (aii): frog skin (ala-pro-gly-[ile3, val5]-ang ii), human [( asp1, ile5]-aii), and japanese goosefish [( asn1-val5]-aii). frog-skin aii increased the short-circuit current (scc) significantly after it was added to the dermal side of the isolated skin of the south american frogs, leptodactylus chaquensis and ocellatus, and the toad, bufo arenarum, in conc ... | 1983 | 6418648 |
| species affinity and infracommunity ordination of helminths of leptodactylus chaquensis (anura: leptodactylidae) in two contrasting environments from northeastern argentina. | one hundred seventy-two frogs (leptodactylus chaquensis) were collected from november 2002 to november 2003, in agricultural (n = 132) and nonagricultural (n = 40) areas. both sites are near the city of corrientes, argentina. the main goals of this study were as follows: (1) to determine the helminth parasite community in agricultural and nonagricultural habitats; (2) to analyze the relationships between helminth parasites and site of infection, frog body size, and gender; (3) to identify and ex ... | 2006 | 17304791 |
| first record of trypanosoma chattoni in brazil and occurrence of other trypanosoma species in brazilian frogs (anura, leptodactylidae). | the present study provides the first record of trypanosoma chattoni mathis and leger, 1911, in a new host, leptodactylus fuscus schneider, 1799 (anura, leptodactylidae), and the occurrence of trypanosoma rotatorium-like species in leptodactylus chaquensis cei, 1950. the anurans were captured in the state of mato grosso, brazil. blood samples were obtained by cardiac puncture, and blood smears were examined for the presence of hemoparasites. the trypanosoma rotatorium-like species in this study r ... | 2008 | 18372634 |
| niche specificity of two glypthelmins (trematoda) congeners infecting leptodactylus chaquensis (anura: leptodactylidae) from argentina. | sixty-five specimens of the frog leptodactylus chaquensis were infected by 2 glypthelmins species (glypthelmins repandum: 41%, and glypthelmins palmipedis: 38%) in the small intestine. this study was designed to determine the site specificity of both species along the length of the small intestine by analyzing the distribution, niche overlap, morphological characteristics, and population dynamics. the location of g. palmipedis is very restricted, with the core infection site in the anterior smal ... | 2009 | 19152236 |
| hemoparasites of the genus trypanosoma (kinetoplastida: trypanosomatidae) and hemogregarines in anurans of the são paulo and mato grosso do sul states - brazil. | wild animals are exposed to numerous pathogens, including hemoparasites. the trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads). the identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. there areno studies, however, based on the biological cycle of these hemoparasites. the objective of the present study was toevaluate the presence of hemogregarines and ... | 2009 | 19488624 |
| anurans as paratenic hosts in the transmission of hepatozoon caimani to caimans caiman yacare and caiman latirostris. | prevalence of hepatozoon caimani has been reported in 76% of caimans caiman yacare from the pantanal region. culex (melanoconion) spp. mosquitoes were recently identified as natural vectors of this parasite. however, culicids are not typically eaten by crocodilians, suggesting that the main transmission route is through ingestion of insectivorous vertebrates, such as anurans. the susceptibility of wild frogs leptodactylus chaquensis, leptodactylus podicipinus and scinax nasicus to infection by h ... | 2011 | 21808978 |
| effect of cholesterol and phosphatidylcholine of different chain length on acrosome breakdown and fertilizing capacity of amphibian spermatozoa. | the effect of different lipids on the fertilizing capacity of bufo arenarum spermatozoa and on acrosome breakdown of leptodactylus chaquensis spermatozoa was studied. sonicated vesicles of egg yolk phosphatidylcholine (1 mm) were as effective as vesicles of egg yolk phosphatidylcholine:cholesterol (molar ratio 1:0.9) in inhibiting the fertilizing capacity of bufo arenarum spermatozoa. this suggests that cholesterol depletion from the spermatozoa was not the cause of the fertility loss. bufo aren ... | 2011 | 3147938 |
| characterization of hepatozoon spp. in leptodactylus chaquensis and leptodactylus podicipinus from two regions of the pantanal, state of mato grosso do sul, brazil. | hepatozoon sp. are parasites that commonly infect frogs and arthropod vectors. this species has variability in the morphological and morphometric characteristics. due to these variations, the naming of the species is thus impaired and only by visualizing the sporogonic cycle in vector and by molecular studies this problem can be solved. recently, the use of molecular genetics has helped the species denomination. in this work, we collected 145 frogs (68 leptodactylus chaquensis and 77 leptodactyl ... | 2015 | 25645008 |
| cytogenetic analyses of eight species in the genus leptodactylus fitzinger, 1843 (amphibia, anura, leptodactylidae), including a new diploid number and a karyotype with multiple translocations. | the karyotypes of leptodactylus species usually consist of 22 bi-armed chromosomes, but morphological variations in some chromosomes and even differences in the 2n have been reported. to better understand the mechanisms responsible for these differences, eight species were analysed using classical and molecular cytogenetic techniques, including replication banding with brdu incorporation. | 2012 | 23268622 |
| trombiculid mites (hannemania sp.) in leptodactylus chaquensis (amphibia: anura) inhabiting selected soybean and rice agroecosystems of argentina. | trombiculid mites are known to parasitize a variety of amphibian species; however, few comparisons of mite parasitism among sites have been made. here, hannemania sp. parasitism in frogs (leptodactylus chaquensis) inhabiting agroecosystems from mideastern argentina was described. a total of 40 adult frogs (22 females and 18 males) were analyzed to detect ectoparasite hannemania spp. larvae. prevalence and mean abundance of hannemania sp. were consistently higher in frogs from the agroecosystems ... | 2012 | 23082522 |
| b-esterase activities and blood cell morphology in the frog leptodactylus chaquensis (amphibia: leptodactylidae) on rice agroecosystems from santa fe province (argentina). | activity of b-esterases (bche: butyrylcholinesterase and cbe: carboxylesterase using two model substrates: α-naphthyl acetate and 4-nitrophenyl valerate) in a native frog, leptodactylus chaquensis from rice fields (rf1: methamidophos and rf2: cypermethrin and endosulfan sprayed by aircraft) and non-contaminated area (pristine forest) was measured. the ability of pyridine-2-aldoxime methochloride (2-pam) to reactivate bche levels was also explored. in addition, changes in blood cell morphology an ... | 2011 | 21113795 |
| response of frog and toad skin to norepinephrine. | maintenance of a hydrated integument is essential to the normal function of amphibian skin, and amphibians have developed mechanisms to minimize cutaneous dessication. the present work was conducted on skins of amphibians exhibiting a clear preference for either of two such mechanisms to study the influence of such mechanisms on the characteristics of epithelial transport. the response to norepinephrine (ne) was studied in isolated skins of a semiaquatic frog (leptodactylus chaquensis), known to ... | 1997 | 9505424 |
| amphibian cross-fertilization and polyspermy. | a string of oocytes from bufo arenarum (ba) was inseminated with spermatozoa from ba, leptodactylus chaquensis (lch), or bufo paracnemis (bp). homologous insemination resulted in monospermic eggs and normal development, while in the case of heterologous fertilization both polyspermy and abnormal development were the rule. oocytes from ba inseminated with homologous spermatozoa, when reinseminated 30 sec after the first insemination with heterologous spermatozoa, exhibit a high rate of polyspermy ... | 1994 | 7931127 |
| hybridization between bufo arenarum and leptodactylus chaquensis. | | 1966 | 6013504 |
| altered development, oxidative stress and dna damage in leptodactylus chaquensis (anura: leptodactylidae) larvae exposed to poultry litter. | poultry litter (pl), which is usually used as organic fertilizer, is a source of nutrients, metals, veterinary pharmaceuticals and bacterial pathogens, which, through runoff, may end up in the nearest aquatic ecosystems. in this study, leptodactylus chaquensis at different development stages (eggs, larval stages 28 and 31 here referred to as stages i, ii and iii respectively) were exposed to pl test sediments as follows: 6.25% (t1), 12.5% (t2); 25% (t3); 50% (t4); 75% (t5); 100% pl (t6) and to d ... | 2017 | 28505481 |
| diet and resource partitioning among anurans in irrigated rice fields in pantanal, brazil. | artificial ponds or irrigated systems scattered throughout farmlands can offer important habitats for anurans and can be interesting sites for research on species resources use in a changing landscape. this study describes the diet and resource partitioning among anurans inhabiting irrigated rice fields in the pantanal region. twenty categories of prey were found in the stomachs of leptodactylus chaquensis, l. elenae, l. podicipinus and rhinella bergi, the most frequent being coleoptera, hymenop ... | 2011 | 21881788 |
| checklist of nematode parasites of amphibians from argentina. | this review includes information about 47 taxa of nematode parasites reported from 34 species of argentinean amphibians, all belonging to order anura (33 native species and 1 introduced species). thirty four nematode species have been reported as adults and 13 species were reported as larvae (10 taxa) or juveniles (3 taxa). two species, cosmocerca parva and c. podicipinus (cosmocercidae), collected as adults, are the most commonly occurring adult nematodes in argentinean amphibians; each of them ... | 2015 | 26249967 |
| differences in responsiveness and sensitivity to exogenous disruptors of the thyroid gland in three anuran species. | anuran larval development comprises tissues/organs/systems that are: exclusively of larvae, able to be remodelled, and those of postmetamorphic stages. also, the anuran larval development is characterized by inter-related parameters: time, size and shape forming part of growth and differentiation. the anuran metamorphosis starts when growth and differentiation achieve a threshold that differs among species since it is regulated by a number of external (environmental) and internal (hormonal) proc ... | 2019 | 31613429 |
| metacercariae of strigeidae parasitizing amphibians of the chaco region in argentina. | the goal of the present study was to analyze the metacercariae found in adult amphibians collected in the argentinean chaco region. a total of 194 frogs, leptodactylus chaquensis, leptodactylus latinasus, and lepidobatrachus laevis was examined for digeneans. three different larval trematodes of the genus strigea (digenea, strigeidae) were found infecting the liver, mesentery, body cavity, and muscle of frogs. these metacercariae are described and illustrated for the first time and provide new i ... | 2019 | 30994754 |
| biodiversity of trematodes associated with amphibians from a variety of habitats in corrientes province, argentina. | the main goals of this study were to compare the richness of parasitic trematodes in amphibians with diverse habits (terrestrial, fossorial, semi-aquatic and arboreal), and to evaluate whether the composition of the trematode community is determined by ecological relationships. specimens were collected between april 2001 and december 2006 from a common area (30 ha) in corrientes province, argentina. trematodes of amphibians in this area comprised a total of 19 species, and were dominated by comm ... | 2013 | 22874101 |
| biological drivers of individual-based anuran-parasite networks under contrasting environmental conditions. | understanding the mechanisms driving host-parasite interactions has important ecological and epidemiological implications. traditionally, most studies dealing with host-parasite interaction networks have focused on species relationship patterns, and intra-population variation in such networks has been widely overlooked. in this study, we tested whether the composition of parasite communities of five anuran species (leptodactylus chaquensis, leptodactylus fuscus, leptodactylus podicipinus, pseudi ... | 2020 | 32578526 |
| electron microscopy observations on testis and spermatozoa of leptodactylus chaquensis (anura, leptodactylidae). | scanning and transmission electron microscopy were used to investigate the fine structure of the testis and spermatozoa of toad leptodactylus chaquensis. our observations indicate that germinal compartment contains sertoli (sc) and germ cells. the tight junctions and desmosomes among sc indicate the existence of an hematotesticular barrier in charge of maintaining the differences in the composition of the germinal and interstitial compartments. during spermatogenesis, sc acts as a structural sup ... | 2018 | 29179007 |
| leptodactylus chaquensis cei, 1950 (leptodactylidae, leptodactylinae): extension of the distribution in state of rio grande do sul, southern brazil. | | 2017 | 28355389 |
| plasma retinoids concentration in leptodactylus chaquensis (amphibia: leptodactylidae) from rice agroecosystems, santa fe province, argentina. | retinoids are known to regulate important processes such as differentiation, development, and embryogenesis of vertebrates: alteration in endogenous retinoids concentration is linked with teratogenic effects. retinol (roh), retinoid acid (ra), and isoform 13-cis-retinoic acid (13-cis-ra), in plasma of a native adults frog, leptodactylus chaquensis from a rice field (rf) and a forest (reference site; rs) were measured. roh did not vary between treatment sites. ra and 13-cis-ra activities were hig ... | 2015 | 25880706 |
| ultrastructure of the oviductal mucosa of leptodactylus chaquensis. analysis of the preovulatory and postovulatory periods. | in the present study we analysed the ultrastructural characteristics of the oviductal mucosa of leptodactylus chaquensis during the preovulatory period and immediately after ovulation. epithelial secretory cells, ciliated cells, basal cells and glandular secretory cells are described. during the preovulatory period, the oviduct exhibits its maximum degree of development at both the epithelial and the glandular levels, with numerous secretory cells that contain a large number of secretory granule ... | 2015 | 24964201 |
| spermatogenesis in leptodactylus chaquensis. histological study. | the organization and the histological characteristics of leptodactylus chaquensis testis throughout the reproductive cycle were analyzed in the presented study. gonads of adult males, processed with routine techniques for optical microscopy, revealed that during the reproductive period the seminiferous tubules were characterized by presentation of a large number of cysts, germ cells at the same maturation stage supported by sertoli cells. all the germ line cells were also present in the postrepr ... | 2014 | 23171585 |
| ultrastructure of poison glands of south american frogs: a comparison between physalaemus albonotatus and leptodactylus chaquensis (anura: leptodactylidae). | serous (poison) cutaneous glands of the leptodactylid species physalaemus albonotatus and leptodactylus chaquensis were compared using light and transmission electron microscopy. glands in the two species share structural traits common in anurans, including the peripheral contractile sheath (myoepithelium) and the syncytial secretory unit that produces, stores, and modifies the poison. at the ultrastructural level, early steps of poison production are also similar and fit the usual path of prote ... | 2005 | 15614827 |
| the effect of hypophysectomy on the histology and acid phosphatase distribution in the testes of leptodactylus chaquensis. | | 1969 | 5800612 |
| [experimental auxogenic effect of serum gonadotropins in gonadpituitary interrelation of male leptodactyl (leptodactylus chaquensis) treated with testosterone]. | | 1953 | 13067460 |