Cochlodinium fulvescens sp. nov. (Gymnodiniales, Dinophyceae), a new chain‐forming unarmored dinoflagellate from Asian coasts

Abstract

Cellular morphology and the phylogenetic position of a new unarmored photosynthetic dinoflagellate Cochlodinium fulvescens Iwataki, Kawami et Matsuoka sp. nov. were examined by light microscopy and molecular phylogenetic analyses based on partial large subunit ribosomal DNA (LSU rDNA) and small subunit ribosomal DNA (SSU rDNA) sequences. The cells of C. fulvescens closely resemble C. polykrikoides, one of the most harmful red tide forming dinoflagellates, due to it possessing a cingulum encircling the cell approximately twice, a spherical nucleus positioned in the anterior part of the cell and an eyespot-like orange pigmented body located in the dorsal side of the epicone, as well as formation of cell-chains. However, this species is clearly distinguished from C. polykrikoides based on several morphological characteristics, namely, cell size, shape of chloroplasts and the position of narrow sulcus situated in the cell surface. The sulcus of C. fulvescens is located at the intermediate position of the cingulum in the dorsal side, whereas that of C. polykrikoides is situated immediately beneath the cingulum. LSU rDNA phylogenies indicated that C. fulvescens is clearly distinct from, but closely related to C. polykrikoides among dinoflagellates.

Occurrence of Cochlodinium fulvescens (Gymnodiniales: Dinophyceae) in the southwestern Gulf of California

“…2K-L) is similar to C. fulvescens as both species form cell chains and have a nucleus and an eyespot located in the anterior dorsal part of the cell (Iwataki et al 2007. The presence of an eyespot was demonstrated for C. polykrikoides by TEM in Iwataki et al (2010).…”

“…Cochlodinium fulvescens is a bloom-forming dinoflagellate first found in Tachibana Bay (west Japan), Hurun Bay (South Sumatra), Indonesia (Iwataki et al 2007), British Columbia , California , Curtiss et al 2008, Kudela & Gobler 2012 (Figs. 2K-L) is similar to C. fulvescens as both species form cell chains and have a nucleus and an eyespot located in the anterior dorsal part of the cell (Iwataki et al 2007.…”

“…According to the recent worldwide review of marine dinoflagellates (Gómez 2011), there are 35 species of Cochlodinium. Cochlodinium fulvescens Iwataki, Kawami & Matsuoka, 2007 was recently described as a new species (Iwataki et al 2007). Taxonomy and distribution of Cochlodinium species have occasionally been studied in Mexico.…”

The outbreak of Chochlodinium sp.: the red tide maker in the coastal of Lampung Bay

“…However, no Cochlodinium bloom was ever observed in Indonesia. Previous research had identified C. fulvescens phytoplankton in December 2003 in Lampung Hurun Bay which was an area for mariculture in floating net cages; however, this species was found not to induce red tides as that occurred in 2012 [6].…”

“…Figure 3 Morphological comparison among Cochlodinium sp. occurred in Lampung Bay, C. fulvescens [6,17] and C. polykrikoides [6] is described below (table 3). Furthermore, it is evident that Choclodinium sp.…”