The role of Spadefoot Toad tadpoles in wetland trophic structure as influenced by environmental and morphological factors
Citation
The role of Spadefoot Toad tadpoles in wetland trophic structure as influenced by environmental and morphological factors: Canadian Journal of ZoologyCan. J. Zool., v. 89, iss. 1, p. 47-59.
Summary
Larval amphibians reach high densities in playa wetlands in the Southern Great Plains (SGP), USA, and thus may influence the entire structure and function of these ecosystems. We investigated whether both carnivorous and omnivorous morphotypes of Spadefoot Toad tadpoles (New Mexico Spadefoot, Spea multiplicata (Cope, 1863), and Plains Spadefoot, Spea bombifrons (Cope, 1863)) would exhibit a macrophagous feeding behavior that would allow them to occupy several trophic levels in playas. We also compared tadpole diets and foregut widths as influenced by the land use surrounding playas (cultivated versus grassland watersheds), year (dry versus wet year), and body size (snout-to-vent length). Tadpole diets were dominated by detritus and [...]
Summary
Larval amphibians reach high densities in playa wetlands in the Southern Great Plains (SGP), USA, and thus may influence the entire structure and function of these ecosystems. We investigated whether both carnivorous and omnivorous morphotypes of Spadefoot Toad tadpoles (New Mexico Spadefoot, Spea multiplicata (Cope, 1863), and Plains Spadefoot, Spea bombifrons (Cope, 1863)) would exhibit a macrophagous feeding behavior that would allow them to occupy several trophic levels in playas. We also compared tadpole diets and foregut widths as influenced by the land use surrounding playas (cultivated versus grassland watersheds), year (dry versus wet year), and body size (snout-to-vent length). Tadpole diets were dominated by detritus and diatoms and tadpole foreguts increased with body size. Generally, more arthropods and less cyanobacteria were found in Spea tadpole diets as tadpoles grew larger, suggesting they influence different trophic levels with age. Foreguts were wider in carnivores than omnivores, sugg..., Les larves d’amphibiens atteignent de fortes densités dans les terres humides des playas du sud des Grandes Plaines (SGP), É.-U., et peuvent ainsi influencer l’ensemble de la structure et du fonctionnement de ces écosystèmes. Nous examinons si les morphotypes carnivores et omnivores des têtards des crapauds pieds-en-bêche (le crapaud du Nouveau-Mexique, Spea multiplicata (Cope, 1863), et le crapaud des plaines, Spea bombifrons (Cope, 1863)) possèdent tous deux un comportement alimentaire macrophage qui leur permettrait d’occuper plusieurs niveaux trophiques dans les playas. Nous avons aussi comparé les régimes alimentaires des têtards et les largeurs du tube digestif antérieur en fonction de l’utilisation des terres autour des playas (bassins versants cultivés par rapport aux bassins de prairie), de l’année (année sèche ou humide) et de la taille corporelle (longueur du museau à l’évent). Les régimes alimentaires des têtards sont dominés par le détritus et les diatomées et les tubes digestifs antérieurs d...
