새 논 문

본 연구팀이 Journal of Eukaryotic Microbiology(JEM)에 제출한 논문(아래)이 2011년 11월 16일자로 출판되었습니다.

본 논문은 새로운 속, 새로운 종인 Gyrodiniellum shiwhaense (자이로디니엘럼 시화엔스)의 포식에 관한 연구입니다. 이 종은 와폄모류에서는 드물게 nematocyst라는 독침을 가지고 있는 종입니다. 본 논문을 통하여 이 종이 다양한 먹이를 포식하는데, 먹이에 빨대(peduncle)을 꽂아 내용물을 흡수한다는 새로운 사실을 밝혔습니다. 이 종은 새로운 해양생태계 교란생물이므로, 앞으로 이들의 세계적 분포를 연구해야 할 것으로 판단됩니다. 본 논문이 나오기까지 도움을 주신 분들께 진심으로 감사드립니다.

Feeding by the Newly Described, Nematocyst-Bearing Heterotrophic Dinoflagellate Gyrodiniellum shiwhaense

HAE JIN JEONG, KYUNG HA LEE, YEONG DU YOO, NAM SEON KANG, KITACK LEE

ABSTRACT: We explored the feeding ecology of the newly-described, nematocyst-bearing heterotrophic dinoflagellate Gyrodiniellum shiwhaense (GenBank Accession number = FR720082). Using several different types of microscopes and high-resolution video-microscopy, we investigated feeding behavior and types of prey species that G. shiwhaense feeds upon. Additionally, we measured its growth and ingestion rates on its optimal algal prey – the cryptophyte Teleaulax sp. and the dinoflagellate Amphidinium carterae as a function of prey concentration. These rates were measured for other edible prey at single prey concentrations at which the growth and ingestion rates of G. shiwhaense were saturated. After anchoring the prey with a tow filament, G. shiwhaense fed using a peduncle, ingesting small algal species with equivalent spherical diameters (ESDs) of < 13 µm. However, it did not feed on larger algal species that had ESDs ≥ 13 µm or the small diatom Skeletonema costatum. The specific growth rates for G. shiwhaense feeding upon Teleaulax sp. and A. carterae increased rapidly with increasing mean prey concentration before saturating at concentrations of ca. 180--430 ng C/ml. The maximum specific growth rate of G. shiwhaense on Teleaulax sp. and A. carterae were 1.05/d and 0.82/d, respectively. However, Heterosigma akashiwo, an optimal or suboptimal prey for many peduncle-feeding dinoflagellates, did not support positive growth of G. shiwhaense. The maximum ingestion rates of G. shiwhaense on Teleaulax sp. and A. carterae were 0.35 ng C/grazer/d (i.e. 21 cells/grazer/d) and 0.54 ng C/grazer/d (i.e. 11 cells/grazer/d), respectively. The calculated grazing coefficients attributable to G. shiwhaense on co-occurring cryptophytes and Amphidinium spp. were 0.01--1.87/d and 0.08--2.60/d, respectively. Our results suggest that G. shiwhaense can have a considerable grazing impact on algal populations.

Key Words. Food web, Growth, Harmful Algal Bloom, Ingestion, Peduncle, Protist, Red tide