Predatory invertebrates indirectly impact leaf-litter breakdown by different foragers in temporary wetlands

JARA, F G; PUETA M

JOURNAL OF ZOOLOGY (1987)

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2023 vol. 319 p. 274 - 284

0952-8369

Temporary wetlands constitute a reservoir of fauna, many of which are endemicspecies well adapted to the typical dry–flooded cycle. The degradation of organicmatter (both autochthonous and allochthonous) is an important process in temporarywetlands. Wetland animals like caddisfly and anuran larvae participate directlyand indirectly in litter breakdown. Both groups also experience predation by invertebratesand vertebrates, which could alter the dynamics of litter breakdown. Weused mesocosms to experimentally study the roles of caddisfly and tadpoles in leaflitter breakdown in the presence of a caged predator. We investigated how the presenceof different types of forager (larvae of the caddisfly Verger vespersus andBatrachyla taeniata tadpoles) impacts leaf litter breakdown and also whether thepresence of a caged belostomatid predator affected this process. Additionally, weinvestigated the behavioral response of B. taeniata tadpoles and V. vespersus larvaeto predation risk cues from belostomatids previously fed on tadpoles or caddisflies.Our results indicated that only caddisfly larvae have a significant impact on litterbreakdown. Predation risk did not influence the process, caddisfly larvae exposedto a caged predator reached the pupal stage more quickly than larvae that were notthus exposed, and tadpoles significantly reduced their activity in response to predationrisk cues. None of the life-history parameters of B. taeniata were affected bythe predator, but tadpoles accelerated their development in warmer water. Our studyis the first in South America to analyze the interactions between a common assemblageof tadpoles and caddisfly larvae and their impact on leaf litter breakdownwhen they experience predation risk. The model used here contributes to ourunderstanding of ecosystem processes such as leaf litter breakdown and the impactof different biotic and abiotic variables when foragers co-occur in the food webs oftemporary aquatic systems.