Skip to Main Content
Food Web Structure and Basal Resource Utilization along a Tropical Island Stream Continuum, Puerto Rico.Author(s): James G. March; Catherine M. Pringle
Source: BIOTROPICA 35(1): 84–93
Publication Series: Miscellaneous Publication
PDF: Download Publication (166 B)
DescriptionTropical stream food webs are thought to be based primarily on terrestrial resources (leaf litter) in small forested headwater streams and algal resources in larger, wider streams. In tropical island streams, the dominant consumers are often omnivorous freshwater shrimps that consume algae, leaf litter, insects, and other shrimps. We used stable isotope analysis to examine (1) the relative importance of terrestrial and algal-based food resources to shrimps and other consumers and determine (2) if the relative importance of these food resources changed along the stream continuum. We examined δ15N and δ13C signatures of leaves, algae, macrophytes, biofilm, insects, snails, fishes, and shrimps at three sites (300, 90, and 10 m elev.) along the Río Espíritu Santo, which drains the Caribbean National Forest, Puerto Rico. Isotope signatures of basal resources were distinct at all sites. Results of two-source δ13C mixing models suggest that shrimps relied more on algal-based carbon resources than terrestrially derived resources at all three sites along the continuum. This study supports other recent findings in tropical streams, demonstrating that algal-based resources are very important to stream consumers, even in small forested headwater streams. This study also demonstrates the importance of doing assimilation-based analysis (i.e., stable isotope or trophic basis of production) when studying food webs.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationMarch, James G.; Pringle, Catherine M. 2003. Food Web Structure and Basal Resource Utilization along a Tropical Island Stream Continuum, Puerto Rico. BIOTROPICA 35(1): 84–93
KeywordsCaribbean, Decapoda, Greater Antilles, lotic, prawn, Puerto Rico, rain forest, RCC, river, species interactions
- Effects of different types of conditioning on rates of leaf-litter shredding by Xiphocaris elongata, a Neotropical freshwater shrimp.
- Spatial and temporal variation in invertebrate consumer diets in forested and herbaceous wetlands
- Response of nutrients, biofilm, and benthic insects to salmon carcass addition.
XML: View XML