Morphological characterization and molecular detection of potential harmful diatom, pseudo-nitzschia from Malaysian water
Bibliographic record
Abstract
The diatom, Pseudo-nitzschia is a genus that associated with harmful algal blooms \n(HABs) worldwide. One third of the species produce the neurotoxin, domoic acid (DA) \nwhich is a causative agent of amnesic shellfish poisoning (ASP). Research interest in \ntoxic Pseudo-nitzschia thrived after the outbreak of the first ASP case stroked Canada in \n1987. Following the incidence, numerous studies have been undertaken throughout the \nopen oceans. However, occurrences of Pseudo-nitzschia spp. were reported as species \ncomplex/complexes due to the taxonomic uncertainty in the genus. This has lead to \nenormous confusion in species identification) In this study, a thorough field survey \nfocused on Pseudo-nitzschia species were undertaken to investigate the spatial \ndistribution pattern and species composition in Malaysian waters. Samplings covered \nlocations in the Andaman Sea, the Straits of Malacca, the South China Sea, Sulu Sea \nand Celebes Sea. Plankton samples were collected from 17 locations using a 20 gmmesh \nplankton net haul. Samples were subjected to acid wash treatment before detailed \nmorphological observations under transmission electron microscope (TEM). \nIdentification of Pseudo-nitzschia species was based on the frustules morphology with \nmorphometric measurements. In total, 22 species were identified; in which 16 were new \nrecords in Malaysia, and a new morphotype discovered. Among the toxic species found, \nincluding P. brasiliana, P. caciantha, P. calliantha, P. cuspidata, P. delicatissima, P. \nmultistriata, P. pseudodelicatissima, P. pungens, and P. turgidula were previously \nreported to associate with ASP events worldwide. \nIn order to aid the species identification of this complex species, molecular \napproaches have been introduced in Pseudo-nitzschia taxonomy. Molecular \nphylogenetic analyses are applied based on a genetic marker to resolve the Pseudonitzschia \nspecies complex/complexes. In this study, whole cell fluorescence in situ \nhybridization (FISH), a rapid molecular detection tool was applied on both field and \ncultured samples. Two toxic species, P. pungens were used as model species in FISH \noptimization and on-field application. Species-specific probes were designed in silico. \nThe accessibilities of probes were tested in silico based on complete 28S rRNA \nsecondary structure information. The probes were successfully optimized on clonal \ncultures and natural spiked samples. Whole-cell FISH was proven as a potential rapid \ndetection tool for monitoring of toxic Pseudo-nitzschia species in Malaysia. This study \nhas provided further insight and better understanding on Pseudo-nitzschia taxonomy \nusing both the morphological and molecular approaches. The finding of a new \nmorphotype warrants further investigation to obtain genetic evidence. FISH method \nwith species specific probes on targeted Pseudo-nitzschia species are proposed as \nmonitoring tools for the related agency in Malaysia.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".