1 research outputs found
A Non-Toxigenic But Morphologically And Phylogenetically Distinct New Species Of Pseudo-Nitzschia, P. Sabit Sp. Nov. Bacillariophyceae)
A new species of Pseudo-nitzschia (Bacillariophyceae)
is described from plankton samples collected from
Port Dickson (Malacca Strait, Malaysia) and
Manzanillo Bay (Colima, Mexico). The species
possesses a distinctive falcate cell valve, from which
they form sickle-like colonies in both environmental
samples and cultured strains. Detailed observation of
frustules under TEM revealed ultrastructure that
closely resembles P. decipiens, yet the new species
differs by the valve shape and greater ranges of
striae and poroid densities. The species is readily
distinguished from the curve-shaped P. subcurvata
by the presence of a central interspace. The
morphological distinction is further supported by
phylogenetic discrimination. We sequenced and
analyzed the nuclear ribosomal RNA genes in the LSU
and the second internal transcribed spacer, including
its secondary structure, to infer the phylogenetic
relationship of the new species with its closest
relatives. The results revealed a distinct lineage of the
new species, forming a sister cluster with its related
species, P. decipiens and P. galaxiae, but not with
P. subcurvata. We examined the domoic acid (DA)
production of five cultured strains from Malaysia by
Liquid chromatography-mass spectrometry (LC-MS),
but they showed no detectable DA. Here, we present
the taxonomic description of the vegetative cells,
document the sexual reproduction, and detail the
molecular phylogenetics of Pseudo-nitzschia sabit sp. nov