A re-investigation of the bloom-forming unarmored dinoflagellate Karenia longicanalis (syn. Karenia umbella) from Chinese coastal waters

TY - JOUR

T1 - A re-investigation of the bloom-forming unarmored dinoflagellate Karenia longicanalis (syn. Karenia umbella) from Chinese coastal waters

AU - Wang, Jianyan

AU - Cen, Jingyi

AU - Li, Si

AU - Lü, Songhui

AU - Moestrup, Øjvind

AU - Chan, Kin Ka

AU - Jiang, Tao

AU - Lei, Xiangdong

PY - 2018

Y1 - 2018

N2 - The dinoflagellate genus Karenia is known for recurrent harmful blooms worldwide. However, species diversity of the genus is generally overlooked owing to the difficulty of identifying small unarmored dinoflagellates. We have established four clonal cultures of Karenia longicanalis isolated from the type locality, Hong Kong harbor (strain HK01) and other three locations along the Chinese coasts (strains YB01, DT01, and NJ01). The morphology of the strain was studied by light and scanning electron microscopy (LM and SEM) and the pigment composition analyzed by high-performance liquid chromatography. We provide the first molecular data of K. longicanalis based on the large subunit (LSU) rRNA gene sequence and internal transcribed spacer (ITS). The four strains showed identical LSU rDNA sequences with a similarity of 99.4% to the holotype of Karenia umbella (strain KUTN05) from Australia. In the ITS phylogeny, the sequence of K. umbella branched between the Chinese strains of K. longicanalis. A careful comparison of the morphology of K. longicanalis and K. umbella reveals the similarity in the diagnostic characters. Differences may appear due to the sample treatment for SEM. We conclude that K. umbella is a junior synonym of K. longicanalis.

AB - The dinoflagellate genus Karenia is known for recurrent harmful blooms worldwide. However, species diversity of the genus is generally overlooked owing to the difficulty of identifying small unarmored dinoflagellates. We have established four clonal cultures of Karenia longicanalis isolated from the type locality, Hong Kong harbor (strain HK01) and other three locations along the Chinese coasts (strains YB01, DT01, and NJ01). The morphology of the strain was studied by light and scanning electron microscopy (LM and SEM) and the pigment composition analyzed by high-performance liquid chromatography. We provide the first molecular data of K. longicanalis based on the large subunit (LSU) rRNA gene sequence and internal transcribed spacer (ITS). The four strains showed identical LSU rDNA sequences with a similarity of 99.4% to the holotype of Karenia umbella (strain KUTN05) from Australia. In the ITS phylogeny, the sequence of K. umbella branched between the Chinese strains of K. longicanalis. A careful comparison of the morphology of K. longicanalis and K. umbella reveals the similarity in the diagnostic characters. Differences may appear due to the sample treatment for SEM. We conclude that K. umbella is a junior synonym of K. longicanalis.

KW - harmful algal blooms (HABs)

KW - internal transcribed spacer (ITS)

KW - large subunit (LSU) rRNA

KW - morphology

KW - phylogeny

KW - phytoplankton

U2 - 10.1007/s00343-019-7191-4

DO - 10.1007/s00343-019-7191-4

M3 - Journal article

AN - SCOPUS:85058981498

SN - 2096-5508

VL - 36

SP - 2202

EP - 2215

JO - Journal of Oceanology and Limnology

JF - Journal of Oceanology and Limnology

IS - 6

ER -