Alkaloids in the skin glands of poison frogs serve as a chemical defense against predation, and almost all of these alkaloids appear to be sequestered from dietary arthropods. Certain alkaloid-containing ants have been considered the primary dietary source, but dietary sources for the majority of alkaloids remain unknown. Herein we report the presence of approximately 80 alkaloids from extracts...

Remnant populations of leopard frogs within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada either represent the reportedly extinct taxon Rana onca or northern, disjunct Rana yavapaiensis. To determine the evolutionary distinctiveness of these leopard frogs, we evaluated mitochondrial DNA (mtDNA) restriction site v...

Acidic environments are physiological stressors for amphibians. The objective of the present study was to document the effect of an acidic environment on innate immune system function under controlled experimental conditions in Rana pipiens. We developed an in vivo assay, by injecting a suspension of 1-microm fluorescent beads in fluid thioglycollate, to induce peritonitis. The number of perito...

Aims Frogs are well known for their use of sticky tongues to capture elusive prey items. The movements of the tongues are extremely fast and single feeding events usually happen within tenths of a second 1-3 . The forces acting on the tongues during feeding can be multiple times the body weight of the animals 4 . Tongue feeding in frogs is diverse, comprising species that only slightly protrude...

Hormones are a vital component of reproductive processes, intimately acting on both sexes through proteins of pituitary origin that affect the gonads, and steroids of gonadal origin that affect the accessory organs and secondary sexual characters. Reproductive behavioral success is the capability of an organism to outcompete other organisms for a mate and to achieve copulation. Aside from its c...

A third-stage (infective) larva of Dracunculus medinensis, the causative agent of Guinea worm disease, was recovered from a wild-caught Phrynobatrachus francisci frog in Chad. Although green frogs (Lithobates clamitans) have been experimentally infected with D. medinensis worms, our findings prove that frogs can serve as natural paratenic hosts.

The effect of 3 months exposure to short day length (L:D, 9:15) on spermatogenesis in R. cyanophlyctis was studied. There was no difference in the qualitative and quantitative aspect of spermatogenesis between control frogs exposed to ambient photoperiod (L:D, 12.16:11.44) and frogs exposed to short day light. The present findings indicate that light has no role in spermatogenesis in the frog.