| comparative studies on the vascular organization of carotid labyrinths of anurans and caudates. | the three-dimensional structures of the carotid labyrinth in five species of anurans representing four families (rana nigromaculata, rana catesbeiana, bufo japonicus, hyla arborea, and xenopus laevis), and three species of caudates representing three families (cynops pyrrhogaster, hynobius nebulosus, ambystoma mexicanum) were compared using vascular corrosion castings and scanning electron microscopy (sem). anuran carotid labyrinths are spherical in shape and are classified into two groups accor ... | 1990 | 2338718 |
| motion sickness in amphibians. | we explored the question of whether amphibians get motion sickness by exposing anurans (frogs) and urodeles (salamanders) to the provocative stimulus of parabolic aircraft flight. animals were fed before flight, and the presence of vomitus in their containers after flight was used to indicate motion-induced emesis. none of the species that we studied vomited during the 8 to 10 parabolas of each flight. however, at least one specimen from each of the anuran species rana rugosa, rana nigromaculata ... | 1993 | 8216158 |
| estimation of age structure by skeletochronology of a population of hynobius nebulosus in a breeding season (amphibia, urodela). | using skeletochronology, we determined the age structure of adult hynobius nebulosus from kyoto in the breeding season of 1998. from previously marked individuals, the lines of arrested growth proved to be formed once per year, indicating the number of winters each salamander experienced. the age at first reproduction was estimated to be 2.8-2.9 yrs of age in males and 3.8-3.9 yrs in females. the oldest males and females were 9.8-9.9 and 5.8-5.9 yrs of age, respectively, and, therefore the longe ... | 2002 | 12012788 |
| food habit of the juvenile of the japanese newt cynops pyrrhogaster. | the previous study showed that the red coloration of the ventral skin of the japanese newt cynops pyrrhogaster was associated with the number of carotenoid vesicles and the content of carotenoid in the pigment cell of the skin. to elucidate the mechanism for the red coloration of the skin of the newt, we studied the food habit of the juvenile from the japanese newt cynops pyrrhogaster. sixty-two juveniles were collected in fukue island in nagasaki prefecture from november 2000 to may 2002 and di ... | 2003 | 12867714 |
| phylogenetic relationships and phylogeography of hynobius tokyoensis (amphibia: caudata) using complete sequences of cytochrome b and control region genes of mitochondrial dna. | using complete sequences of cytochrome b (cyt b) and control region (cr; d-loop) genes of mitochondrial dna, we investigated the phylogenetic relationships and phylogeography among populations of the salamander hynobius tokyoensis in northern japan. inclusion of populations from aichi, chubu region within hynobius nebulosus by previous results was confirmed because they formed a clade with h. nebulosus. monophyly of h. tokyoensis was supported in all trees analyzed, and two clades consistently e ... | 2007 | 17254807 |
| Phase-II conjugation ability for PAH metabolism in amphibians: Characteristics and inter-species differences. | The present study examines amphibian metabolic activity - particularly conjugation - by analysis of pyrene (a four ring, polycyclic aromatic hydrocarbon) metabolites using high-performance liquid chromatography (HPLC) with fluorescence detector (FD), a mass spectrometry detector (MS) system and kinetic analysis of conjugation enzymes. Six amphibian species were exposed to pyrene (dissolved in water): African claw frog (Xenopus laevis); Tago's brown frog (Rana tagoi); Montane brown frog (Rana orn ... | 2011 | 21819814 |
| correlated histochemical and electron microscopic studies of the esophageal epithelium in the salamander, hynobius nebulosus. | the esophageal epithelium of the adult salamander, hynobius nebulosus, was studied by histochemistry, including periodic acid-shiff (pas), alcian blue both at ph 2.5 and ph 1.0, and alcian blue (ph 2.5)-pas with or without neuraminidase-digestion, and scanning and transmission electron microscopy. the epithelium was columnar in type, comprising partly pseudostratified and partly two-layered architecture; it consisted mainly of ciliated cells, goblet cells, and basal cells. the ciliated cells con ... | 2013 | 3662757 |
| an electrically mediated block to polyspermy in the primitive urodele hynobius nebulosus and phylogenetic comparison with other amphibians. | at fertilization, the egg of the primitive urodele, hynobius nebulosus, produced a fertilization potential which rose from -12 to +47 mv. a similar activation potential was elicited by pricking with a needle, by applying a23187, or by electric shock. the potential change was mediated by an increased permeability to cl-. clamping the egg's membrane potential at +40 mv blocked fertilization, while clamping at +20 mv induced polyspermy. these results indicated the occurrence of an electrical polysp ... | 2009 | 2744241 |
| evidence that the voltage-dependent component in the fertilization process is contributed by the sperm. | to investigate the mechanisms that account for the voltage dependence of fertilization and provide an electrical block to polyspermy, we studied cross-fertilizations between three species of amphibians having different degrees of voltage dependence. anurans, such as the toad bufo japonicus, as well as the primitive urodele hynobius nebulosus, have voltage-dependent fertilization; other urodeles, such as cynops pyrrhogaster, have voltage-independent fertilization (y. iwao, 1989, dev. biol. 134, 4 ... | 2009 | 2744242 |
| functional diversity of voltage-sensing phosphatases in two urodele amphibians. | voltage-sensing phosphatases (vsps) share the molecular architecture of the voltage sensor domain (vsd) with voltage-gated ion channels and the phosphoinositide phosphatase region with the phosphatase and tensin homolog (pten), respectively. vsps enzymatic activities are regulated by the motions of vsd upon depolarization. the physiological role of these proteins has remained elusive, and insights may be gained by investigating biological variations in different animal species. urodele amphibian ... | 2014 | 25347851 |
| genetic diversity among clouded salamanders (hynobius nebulosus) in shiga prefecture. | the japanese clouded salamander (hynobius nebulosus) is a lentic-breeding species distributed throughout western japan. threats, such as habitat loss, have led to it being categorized as a vulnerable species. to explore the phylogeographic features and population differentiation among clouded salamanders in shiga prefecture, we analyzed sequences of the mitochondrial cytochrome b gene. dna samples were collected from 29 distinct breeding sites, and 53 cytochrome b haplotypes were identified. on ... | 2018 | 30298788 |
| effects of photoperiod and temperature on growth and development in clouded salamander (hynobius nebulosus) larvae. | day length is one of the most important factors that organisms use to predict seasonal changes in their environment. several amphibians regulate their growth and development in response to photoperiod. however, many studies have not focused on the ecological effects of the photoperiodic response on growth and development because they use tropical animals, animals from a commercial source or from unknown localities, or extreme light regimens for experiments. in the present study, we examined the ... | 2015 | 26003982 |
| a skeletochronological study of breeding females in a population of japanese clouded salamanders (hynobius nebulosus). | the age structure of breeding females of hynobius nebulosus has not been studied sufficiently. we estimated the ages of 76 individuals from a population in kyoto by using skeletochronology. the mean age and snout-vent length (svl) of this population were 4.6 years and 55.7 mm, respectively. it was estimated that the youngest females breed two years post hatching at a mean svl of 46.5 mm, but a larger number of individuals begins breeding at three years and a mean svl of 52.2 mm. because most mal ... | 2011 | 21385057 |
| immunocytochemical survey of the neuroepithelial endocrine system in the respiratory tract of the tokyo salamander, hynobius nebulosus tokyoensis tago. | the epithelial lining of the respiratory tract of urodeles has been shown to harbor an innervated system of neuroepithelial endocrine (nee) cells. even between phylogenetically closely related species, large differences have been reported in the appearance and chemical coding of the nee system. although urodeles are well suited for the purpose, none of the prior studies have provided an immunocytochemical survey of the nee system in all parts of the respiratory tract. in the present study, many ... | 1994 | 7698899 |
| differentiation of the brain stem structures in the salamander, hynobius nebulosus. | differentiation of the internal structure of the brain stem was analyzed in the salamander with special reference to neurons distributed in the marginal layer. it was found that the salamander brain stem was at first composed exclusively of the mantle layer. the marginal layer later differentiated peripherally. in these developmental stages, the mantle and marginal layers were clearly differentiated: the former was made up exclusively of the somata, while the latter was composed mainly of nerve ... | 1992 | 1449224 |
| electron microscopic studies of the lung of the salamander, hynobius nebulosus: iii. a scanning and transmission electron microscopic observation on neuroepithelial bodies. | | 1985 | 3831857 |
| ultrastructural changes in development and aging of the interrenal cell of the salamander, hynobius nebulosus. | the fine structure of interrenal cells in the salamander, hynobius nebulosus, from prometamorphic larvae to its adult stage, was observed with electron and light microscopes. in all the animals examined the interrenal cell clusters were located at the medial edge of the ventral surface along the total length of each kidney, suggestive of a primitive nature. in larval salamanders, the interrenal cells contained small to moderate numbers of lipid droplets, and their cytoplasm was filled with a tub ... | 1985 | 4038004 |
| electron microscopic studies on the lung of the salamander, hynobius nebulosus: ii. osmiophilic lamellar bodies and alveolar surfactant. | | 1984 | 6549479 |
| electron microscopic studies of the lung of the salamander, hynobius nebulosus: 1. a scanning and transmission electron microscopic observation. | | 1984 | 6483366 |
| electron microscopic studies on the thyroid gland of larval salamanders hynobius nebulosus during metamorphosis. | | 1973 | 4738028 |
| electron microscopic study on the thyroid gland of the salamander hynobius nebulosus in the breeding season. ii. observation under experimental conditions. | | 1973 | 4348239 |
| electron microscopic study on the thyroid gland of the salamander hynobius nebulosus in the breeding season. i. observation under normal conditions. | | 1973 | 4348238 |