| distribution, abundance, and genetic diversity of clinostomum spp. metacercariae (trematoda: digenea) in a modified ozark stream system. | abstract land-use alterations can have profound influences on faunal distributions, including host-parasite relationships. yellow grub trematodes ( clinostomum spp.) have complex life cycles involving 3 hosts: a snail, a fish or amphibian, and a bird. here, we analyze the distribution, prevalence, intensity, abundance, and genetic diversity of encysting metacercariae of clinostomum spp. in salamanders and fishes throughout an aquatic system that includes a natural ozark stream and man-made ponds ... | 2011 | 21506775 |
| the structure and visual function of the eye of larval and adult cave salamanders typhlotriton spelaeus. | | 1964 | 14193846 |
| effects of continuous light and darkness on the eyes of the troglobitic salamander typhlotriton spelaeus. | larval typhlotriton spelaeus collected from five caves in pulaski co., missouri, were kept as larvae or induced to transform in darkness or continuous fluorescent illumination. larvae maintained in darkness for 215 and 279 days had smaller eyes, smaller rod inner and outer segments, and fewer metaphase figures in the germinative zone of the neural retina than comparable larvae maintained in light (258 lux). except for visual cell size, differences were small and for each characteristic exception ... | 1976 | 966284 |
| speciation, phylogeography and evolution of life history and morphology in plethodontid salamanders of the eurycea multiplicata complex. | understanding the complex interactions among environment, genotype and ontogeny in determining organismal phenotypes is cental to many biological disciplines. the eurycea multiplicata complex, endemic to the interior highlands (ozark plateau and ouachita mountains) of eastern north america, comprises a diverse radiation of paedomorphic surface-dwelling (e. tynerensis), metamorphic surface-dwelling (e. multiplicata multiplicata and e. m. griseogaster) and metamorphic subterranean (typhlotriton sp ... | 2004 | 15078455 |
| residual cornea and the degenerate eye of the cryptophthalmic typhlotriton spelaeus. | the cave-dwelling typhlotriton spelaeus larvas live in daylight. the larvas undergo a metamorphosis when the thyroxin level (t3 and t4) increases. they leave aquatic life for terrestrial and subterranean aphotic life. the larval eyes are normal and show good vision response to tests. on the contrary, in the oldest larva and the adult, the eyes are small with poor vision or no vision at all. the lens can disappear but in any case the eyelids grow over the eye. the retinal degeneration takes place ... | 1993 | 8306666 |
| postembryonic eye degeneration in the troglobitic salamander typhlotriton spelaeus. | comparative histological observations of the eyes of typhlotriton spelaeus and several epigean, plethodontid species indicate that the principal postembryonic degenerative changes in the eyes of t. spelaeus involve the eyelids and cornea, visual cells, outer plexiform layer, and the pigment epithelium. ordinarily these changes were initiated after metamorphosis, before attainment of sexual maturity, but a few larvae had degenerating retinae. the corneal epithelium becomes irregular and thin as e ... | 1974 | 30322217 |