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Pyramidodinium spinulosum sp. nov. ( D inophyceae), a sand‐dwelling non‐motile dinoflagellate from the seafloor (36 m deep) off M ageshima I sland, K agoshima, J apan
Author(s) -
Horiguchi Takeo,
Moriya Rui,
Pinto Sohail K.,
Terada Ryuta
Publication year - 2017
Publication title -
phycological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.438
H-Index - 44
eISSN - 1440-1835
pISSN - 1322-0829
DOI - 10.1111/pre.12183
Subject(s) - dinoflagellate , biology , benthic zone , dinophyceae , genus , botany , algae , tide pool , ecology , intertidal zone , phytoplankton , nutrient
SUMMARY A new species of benthic marine dinoflagellate, Pyramidodinium spinulosum H origuchi, M oriya, P into & T erada is described from the deep (36 m) seafloor off M ageshima I sland, K agoshima P refecture, J apan in the subtropical region of the northwest P acific. The life cycle of the dinoflagellate consists of a dominant, attached, dome‐shaped, vegetative form and short‐lasting, motile cell. Asexual reproduction takes place by the formation of two motile cells within each non‐motile cell. The released motile cells swim only for a short period and transform directly into the dome‐shaped vegetative form. The duration of the cell cycle varies and can be extremely long, ranging 5–38 days under culture conditions. The non‐motile cell is enclosed by a cell wall and its surface is covered with many (80 – 130) spines of various length. The dinoflagellate is photosynthetic and contains many (more than 50) discoidal chloroplasts. Phylogenetic analysis reveals that the dinoflagellate is closely related to the type species of the genus Pyramidodinium , P. atrofuscum which also possesses a dominant, attached, non‐motile form. However, P. spinulosum can be clearly distinguished from P. atrofuscum by the cell shape (dome‐shaped vs. pyramid‐shaped) and surface ornamentation (spines vs. wart‐like processes) of the non‐motile form. Based on these morphological differences together with molecular evidence, it was concluded that this organism from a deep water sand sample should be described as a second species of the genus Pyramidodinium , P. spinulosum .