title: MORPHOLOGY AND MOLECULAR CHARACTERIZATION OF PSEUDO-NITZSCHIA (BACILLARIOPHYCEAE) FROM MALAYSIAN BORNEO, INCLUDING THE NEW SPECIES PSEUDO-NITZSCHIA CIRCUMPORA SP. NOV.
abstract: Field sampling was undertaken to investigate the occurrence of Pseudo-nitzschia Peragallo species in eight locations along the coast of Malaysian Borneo. A total of 108 strains of Pseudo-nitzschia species were isolated, and their morphology examined with SEM and TEM. Additionally, molecular data from nuclear-encoded partial LSU rDNA, and ITS regions, were characterized. A total of five species were confidently identified based on a combination of distinct morphological characteristics and supporting molecular evidence: P. brasiliana Lundholm, Hasle & Fryxell, P. cuspidata (Hasle) Hasle, P. dolorosa Lundholm & Moestrup, P. micropora Priisholm, Moestrup & Lundholm, and P. pungens (Grunow) Hasle var. pungens. However, one morphotype from Sarawak, while somewhat similar to P. caciantha, showed significant morphological distinction from this and any other of the currently described species. Most notably this morphotype possessed a characteristic pore arrangement in the poroids, with the fine pores in each perforation sector arranged in circles. Pair-wise sequence comparison of the LSU rDNA between this unidentified morphotype and P. caciantha Lundholm, Moestrup & Hasle, revealed 2.7% genetic divergence. Phylogenetic analyses strongly supported the monophyly of the morphotype. Based upon these supporting data it is here described as a new species, Pseudo-nitzschia circumpora sp. nov. A key to the six species of Pseudo-nitzschia from Malaysian Borneo is presented. Molecular signatures for all species were established based on structural comparisons of ITS2 rRNA transcripts.
authors.affiliation: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, 94300, Malaysia.
authors.forename: Hong-Chang
authors.initials: HC
authors.lastname: Lim
authors.affiliation: Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, 94300, Malaysia.
authors.forename: Chui-Pin
authors.initials: CP
authors.lastname: Leaw
authors.affiliation: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, 94300, Malaysia.
authors.forename: Suriyanti Nyun-Pau
authors.initials: SN
authors.lastname: Su
authors.affiliation: Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, 94300, Malaysia.
authors.forename: Sing-Tung
authors.initials: ST
authors.lastname: Teng
authors.affiliation: Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, 43600, Malaysia.
authors.forename: Gires
authors.initials: G
authors.lastname: Usup
authors.affiliation: Kulliyyah of Science, International Islamic University Malaysia, Bandar Indera Mahkota, Kuantan, Pahang, 25200, Malaysia.
authors.forename: Normawaty
authors.initials: N
authors.lastname: Mohammad-Noor
authors.affiliation: Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, Copenhagen, 1307, Denmark.
authors.forename: Nina
authors.initials: N
authors.lastname: Lundholm
authors.affiliation: School of Marine Biosciences, Kitasato University, Kitasato 1-15-1, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kotaki
authors.affiliation: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, 94300, Malaysia.
authors.forename: Po-Teen
authors.initials: PT
authors.lastname: Lim
keywords: Malaysia; Pseudo-nitzschia; Pseudo-nitzschia circumpora; molecular signature; morphology