Detailed Information

Ecology of Gymnodinium aureolum. I. Feeding in western Korean waters

Cited 58 time in Web of Science Cited 64 time in Scopus

Jeong, Hae Jin; Yoo, Yeong Du; Kang, Nam Seon; Rho, Jung Rae; Seong, Kyeong Ah; Park, Jong Woo; Nam, Gui Sook; Yih, Wonho

Issue Date
Inter-Research Science Publishing
Aquatic Microbial Ecology, Vol.59 No.3, pp.239-255
A bloom-forming dinoflagellate was isolated from coastal waters in western Korea during a red tide event in March 2008 and clonal cultures were established. The dinoflagellate was identified as Gymnodinium aureolum based on morphological and genetic analyses (GenBank accession no. FN392226). We report here for the first time that the red-tide dinoflagellate G. aureolum, which has previously been thought to be exclusively autotrophic, is a mixotrophic species. G. aureolum fed on algal prey using a peduncle. Among the algal prey provided, G. aureolum ingested heterotrophic bacteria, the cyanobacterium Synechococcus sp., and small algal species that had equivalent spherical diameters (ESDs) of <= 11.5 mu m. However, it did not feed on larger algal species (ESD >= 12 mu m) or the small diatom Skeletonema costa turn. The specific growth rates for G. aureolum on the cryptophyte Teleaulax sp. increased continuously with increasing mean prey concentration before saturating at prey concentrations of ca. 190 ng C ml(-1) (11 050 cells ml(-1)). The maximum specific growth rate (mixotrophic growth) of G. aureolum on Teleaulax sp. was 0.169 d(-1), at 20 degrees C under a 14:10 h light:dark cycle of 20 mu E m(-2) S(-1), while its growth rate (phototrophic growth) under the same light conditions without added prey was 0.120 d(-1). The maximum ingestion and clearance rates of G. aureolum on Teleaulax sp. were 0.058 ng C grazer(-1) d(-1) (3.4 cells grazer(-1) d(-1)) and 0.003 mu l grazer(-1) h(-1), respectively. The calculated in situ grazing coefficient for G. aureolum on co-occurring cryptophytes ranged up to 0.498 d(-1). Bioassay results indicated that this strain of G. aureolum is not toxic. Results of the present study suggest that G. aureolum has a potentially considerable grazing impact on algal populations.
Files in This Item:
There are no files associated with this item.
Appears in Collections:

Related Researcher

  • College of Natural Sciences
  • Department of Earth and Environmental Sciences
Research Area Aquatic Microbial Ecology, Biological Oceanography, Plankton


Item View & Download Count

  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.