Trophic position and growth stages of Caddisfly (Stenopsyche marmorata Navas) larvae in the Echi River, Japan
Abstract
We investigated the trophic position of the larval filter-feeding caddisfly species—Stenopsyche marmorata Navas in the Echi River (Japan) using δ13C and δ15N measurements by instar growth stage. We also analyzed δ13C and δ15N of food sources (periphyton and suspended and benthic POM) along the course of the river. The larvae showed some degree of spatial variation in δ13C and δ15N values with a downstream increase in δ13C and δ15N values. Our results demonstrate that the trophic structure of S. marmorata of different larval stages were spatially varying, depending on food sources. Small-sized instars displayed a higher trophic position than larger instars, confirming that their non-selective feeding behavior leads to consumption of items with high δ15N values according to the spatial distribution of food sources in the riverine system.
- Publication:
-
Limnology
- Pub Date:
- August 2013
- DOI:
- 10.1007/s10201-013-0406-z
- Bibcode:
- 2013Limno..14..283S
- Keywords:
-
- Stable isotopes;
- Filter feeding larval caddisfly;
- Food sources;
- Trophic level