Trophic roles of tadpoles in tropical Australian streams
Journal Publication ResearchOnline@JCUAbstract
1. Tadpoles can be abundant consumers in stream ecosystems, and may influence the structure and function of streams through their feeding activities and interactions with other organisms. To understand the contribution of tadpoles to stream functioning, and the potential impact of their loss, it is necessary to determine their diets and how they might influence food-web structure. 2. Using gut-content analysis and stable-isotope analysis of N and C, we determined the main food sources and trophic positions of tadpoles of five native frog species, invertebrates, and fish in upland and lowland Australian Wet Tropics streams. 3. Omnivory was prevalent among the tadpoles and invertebrates. Tadpoles consumed different food according to availability and nutrient quality, but assimilated mainly biofilm and algae. Most tadpoles and invertebrates assimilated the same high-quality foods. 4. Food webs in upland riffles were simplified by local extinction of tadpoles, and were probably simplified in pools in the cooler months by seasonal decline in tadpole abundance. Food-web complexity was increased in some pools by the presence of predatory fish and a greater number of basal sources. 5. As tadpoles are important seasonal components in stream food webs, their local extinction can greatly alter food-web structure and complexity and, possibly, processes such as leaf litter breakdown and sediment accumulation.
Journal
Freshwater Biology
Publication Name
Freshwater Biology
Volume
62
ISBN/ISSN
1365-2427
Edition
N/A
Issue
11
Pages Count
13
Location
N/A
Publisher
Blackwell Publishing
Publisher Url
N/A
Publisher Location
N/A
Publish Date
N/A
Url
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Date
N/A
EISSN
N/A
DOI
10.1111/fwb.13036