Seasonal and diel abundance and feeding patterns ofChaoborus flavicansin Sang-Chun reservoir

Abstract

To document the basic ecological aspects of Chaoborus species, which has never been reported in Korea, we attempted to identify the species, to monitor seasonal and vertical dynamics, and to elucidate trophic relations of the species in Sang-Chun reservoir. Using morphological characteristics, we identified the collected samples as C. flavicans. Also, we compared the distribution of C. flavicans, Daphnia rosea and chlorophyll a to observed seasonal dynamics. The increase of C. flavicans was observed 1Á2 weeks after the increase of D. rosea. Survey of diel vertical migration patterns in the summer season showed that C. flavicans were in hypolimnion at daytime, but moved to the epilimnion at night. Finally, to determine trophic relationships in Sang-Chun reservoir, additional studies on the food web were undertaken by stable isotope analysis. Chaoborus flavicans IÁII instars appear to be filter feeders based on carbon isotope values. Trophic levels of C. flavicans IIIÁIV instars were shown to be higher than other zooplankton based on nitrogen isotope values.

Impact of Chaoborus flavicans ‐Predation on the Zooplankton in a Mesotrophic Lake – a Three Year Study

“…The two older stages were reported to be on a higher trophic level than other zooplankton, as shown by stable isotopes of nitrogen (JEONG and PARK, 2010). In Lake Großer Vätersee the most important impact on the zooplankton community occurred when the larvae had reached the IVth instar which accounted for 90-95% of the yearly consumption.…”

“…Instars I and II fed primarily on phytoplankton, especially on Ceratium species. A stable isotope study of carbon showed these instars to be filter-feeders (JEONG and PARK, 2010). During the instar II stage, composition of the ingested food items slowly changed and started to include small zooplankton species (e.g., rotifers).…”

Molecular Taxonomy of a Phantom Midge Species (Chaoborus flavicans) in Korea

“…Species in Chaoboridae have never known to inhabit Korea until recently, and even the family name did not appear in the Checklist of Insects from Korea (The Entomological Society of Korea and Korean Society of Applied Entomology, 1994). Recently, Jeong (2010) reported Chaoborus flavicans from the Sangchun reservoir in Gyeonggi-do, based mainly on mandible morphology and partial COI sequences. Therefore, their taxonomy and distribution are very poorly understood in Korea.…”

Food web structure in aSalix subfragilisdominated wetland in Hangang estuary using stable isotopes and fatty acid biomarkers

“…In addition, the traditional trophic level concept has limitations with regard to locating omnivorous species such as S. dehaani in food webs (Vander Zanden and Rasmussen 1996). Recently, stable isotopes and fatty acid biomarkers have become popular tools for studying food web structure (Jeong and Park 2010). Stable isotope monitoring can provide an objective and quantitative food web structure when ratios of stable isotopes such as carbon and nitrogen are measured from tissues of biological components in food webs (Vander Zanden et al 1999).…”