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RESEARCH ARTICLE
Contents Vol 59(11)

Experimental dietary manipulations and concurrent use of assimilation-based analyses for elucidation of consumer–resource relationships in tropical streams

Danny C. P. Lau A , Kenneth M. Y. Leung A B and David Dudgeon A C
+ Author Affiliations
- Author Affiliations

A Division of Ecology and Biodiversity, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.

B The Swire Institute of Marine Science, Faculty of Science, The University of Hong Kong, Cape D’Aguilar, Shek O, Hong Kong, P. R. China.

C Corresponding author. Email: ddudgeon@hkucc.hku.hk

Marine and Freshwater Research 59(11) 963-970 https://doi.org/10.1071/MF07213
Submitted: 7 November 2007  Accepted: 25 July 2008   Published: 27 November 2008

Abstract

The relative contribution of autochthonous foods to consumer biomass in small tropical streams is unknown, but extrapolation of findings from temperate forest streams, where food webs are based on allochthonous resources, might be misleading. Experimental dietary manipulations were conducted to investigate the food used by the snail Brotia hainanensis (Pachychilidae), a generalist primary consumer common in Hong Kong streams, through the concurrent use of stoichiometry, stable isotope analysis (SIA) and fatty acid (FA) profiling. Juvenile B. hainanensis collected from the field were cultured under laboratory conditions and fed with conditioned leaf litter, periphyton or commercial fish-food flakes for 6 months and then compared with field-collected snails at the end of the trial. The results of the SIA and FA profiling showed that snails depended primarily on algal food. Prolonged feeding with leaf litter put B. hainanensis under elemental constraints and litter-fed snails deviated from strict stoichiometric homeostasis. Periphyton-fed, flake-fed and field-collected snails contained more total lipids and autochthonous FA biomarkers than litter-fed snails. The concurrent application of assimilation-based analyses allowed effective and accurate elucidation of consumer–resource relationships and, in the present study, confirmed the importance of autochthonous energy in a tropical stream food web. This approach will be useful for investigating complex trophic interactions.

Additional keywords: carbon : nitrogen ratio, cyanobacteria, diatoms, gastropod, Hong Kong.


Acknowledgements

We sincerely thank Ms Lily Ng, Ms Jessie Lai and Ms Alice Chan for their technical support on the chemical analyses. The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. (HKU) 7619/05M) and by a postgraduate studentship awarded to D. C. P. Lau. We thank Dr Timothy Moulton and an anonymous referee for suggestions that helped to improve an earlier version of this manuscript.


References

Adams, T. S. , and Sterner, R. W. (2000). The effect of dietary nitrogen content on trophic level 15N enrichment. Limnology and Oceanography 45, 601–607.
|  CAS | Alexander M. (1961). ‘Introduction to Soil Microbiology.’ (John Wiley & Sons: New York.)

Bligh, E. G. , and Dyer, W. J. (1959). A rapid method of total lipid extraction and purification. Canadian Journal of Biochemistry and Physiology 37, 911–917.
|  CAS | PubMed | Dudgeon D., and Corlett R. (2004). ‘The Ecology and Biodiversity of Hong Kong.’ (Joint Publishing: Hong Kong.)

Dunstan, G. A. , Volkman, J. K. , Barrett, S. M. , Leroi, J. M. , and Jeffrey, S. W. (1993). Essential polyunsaturated fatty acids from 14 species of diatom (Bacillariophyceae). Phytochemistry 35, 155–161.
| Crossref | GoogleScholarGoogle Scholar | Lamberti G. A. (1996). The role of periphyton in benthic food webs. In ‘Algal Ecology: Freshwater Benthic Ecosystems’. (Eds R. J. Stevenson, M. L. Bothwell and R. L. Lowe.) pp. 533–572. (Academic Press: London.)

Lau, D. C. P. , Leung, K. M. Y. , and Dudgeon, D. (2008a). Experimental dietary manipulations for determining the relative importance of allochthonous and autochthonous food resources in tropical streams. Freshwater Biology 53, 139–147.
|  CAS | Lau D. C. P., Leung K. M. Y., and Dudgeon D. (2008b). Autochthonous resources are more important to aquatic consumers than allochthonous sources in tropical headwater streams. Journal of the North American Benthological Society, in press.

Li, A. O. Y. , and Dudgeon, D. (2008). Food resources of shredders and other benthic macroinvertebrates in relation to shading conditions in tropical Hong Kong streams. Freshwater Biology 53, 2011–2025.
| Crossref | GoogleScholarGoogle Scholar | Napolitano G. E. (1999). Fatty acids as trophic and chemical markers in freshwater ecosystems. In ‘Lipids in Freshwater Ecosystems’. (Eds M. T. Arts and B. C. Wainman.) pp. 21–44. (Springer-Verlag: New York.)

Napolitano, G. E. , Hill, G. R. , Guckert, J. B. , Stewart, A. J. , Nold, S. C. , and White, D. C. (1994). Changes in periphyton fatty acid composition in chlorine polluted streams. Journal of the North American Benthological Society 13, 237–249.
| Crossref | GoogleScholarGoogle Scholar | Sterner R. W., and Elser J. J. (2002). ‘Ecological Stoichiometry: the Biology of Elements from Molecules to the Biosphere.’ (Princeton University Press: New Jersey.)

Thorp, J. H. , and Delong, M. D. (1994). The riverine productivity model: an heuristic view of carbon sources and organic processing in large river ecosystems. Oikos 70, 305–308.
| Crossref | GoogleScholarGoogle Scholar |

Thorp, J. H. , and Delong, M. D. (2002). Dominance of autochthonous autotrophic carbon in food webs of heterotrophic rivers. Oikos 96, 543–550.
| Crossref | GoogleScholarGoogle Scholar |

Tomanova, S. , Goitia, E. , and Helešic, J. (2006). Trophic levels and functional feeding groups of macroinvertebrates in neotropical streams. Hydrobiologia 556, 251–264.
| Crossref | GoogleScholarGoogle Scholar |

Torres-Ruiz, M. , Wehr, J. D. , and Perrone, A. A. (2007). Trophic relationships in a stream food web: importance of fatty acids for macroinvertebrate consumers. Journal of the North American Benthological Society 26, 509–522.
| Crossref | GoogleScholarGoogle Scholar |

Vander Zanden, M. J. , and Rasmussen, J. B. (2001). Variation in δ15N and δ13C trophic fractionation: implications for aquatic food web studies. Limnology and Oceanography 46, 2061–2066.
|  CAS |

Vannote, R. L. , Minshall, G. W. , Cummins, K. W. , Sedell, J. P. , and Cushing, C. E. (1980). The River Continuum Concept. Canadian Journal of Fisheries and Aquatic Sciences 37, 130–137.
| Crossref | GoogleScholarGoogle Scholar |

Yam, S. W. R. , and Dudgeon, D. (2005). Stable isotopes investigation of food use by Caridina spp. (Decapoda : Atyidae) in Hong Kong streams. Journal of the North American Benthological Society 24, 68–81.
| Crossref | GoogleScholarGoogle Scholar |