What do tadpoles really eat? Assessing the trophic status of an understudied and imperiled group of consumers in freshwater habitats

Abstract

1. Understanding the trophic status of consumers in freshwater habitats is central to understanding their ecological roles and significance. Tadpoles are a diverse and abundant component of many freshwater habitats, yet we know relatively little about their feeding ecology and true trophic status compared with many other consumer groups. While many tadpole species are labelled herbivores or detritivores, there is surprisingly little evidence to support these trophic assignments. 2. Here we discuss shortcomings in our knowledge of the feeding ecology and trophic status of tadpoles and provide suggestions and examples of how we can more accurately quantify their trophic status and ecological significance. 3. Given the catastrophic amphibian declines that are ongoing in many regions of the planet, there is a sense of urgency regarding this information. Understanding the varied ecological roles of tadpoles will allow for more effective conservation of remaining populations, benefit captive breeding programmes, and allow for more accurate predictions of the ecological consequences of their losses.

Diet and food resource partition among benthic tadpoles of three anuran species in Atlantic Forest tropical streams

“…The presence of fungi in the diet of tadpoles is also rarely reported in literature even though it is an important component in oligotrophic habitats (Altig et al 2007). Studies that address the importance of fungi in the diet of tadpoles were not found, however, Rossa-Feres et al Pfennig et al 2006;Sousa Filho et al 2007;Wickramasinghe et al 2007), and were usually associated with the diet of tadpoles in the later stages of development, unlike the three species of this study, which were in the early stages of development.…”

“…Studies of the composition of the diet of tadpoles are especially important in the tropics, where despite taxonomic diversity being severely threatened by factors that can cause irreparable declines; little is known of the trophic importance of tadpoles in many aquatic environments (Altig et al 2007). This study investigated the allocation of food resources among benthic tadpoles of three hylid species (Aplastodiscus cavicola, Aplastodiscus sibilatus and Bokermannohyla capra) from lotic communities based on the hypotheses that similar ecomorphotypes use similar food resources and that species that coexist in the same micro-habitat must share food sources.…”

Ranavirus Ecology and Evolution: From Epidemiology to Extinction

“…Cannibalism is common in amphibians and reptiles (Crump 1983 ;Polis and Myers 1985 ). Even anuran tadpoles engage in cannibalism and scavenging (Altig et al 2007 ). Two studies found that wood frog and Italian agile frog ( Rana latastei ) tadpoles had greater mortality rates when allowed to scavenge dead FV3-infected conspecifi cs (Pearman et al 2004 ;Harp and Petranka 2006 ).…”

Stress hormones and the fitness consequences associated with the transition to a novel diet in larval amphibians

“…Most species within the Pelobatoidea clade feed on detritus, which is likely the ancestral diet of anuran larvae (Altig et al, 2007). According to character state reconstruction analysis, Spea is the only genus within the Pelobatoidea that has evolved the ability to exploit macroscopic prey (Ledón-Rettig et al, 2008).…”