Dinophysis acuta is a marine unicellular protist, and is the largest among Dinophysis. It is an armoured species with a distinct body covering called theca or test. The body is laterally compressed with a small, cap-like epitheca and a much larger hypotheca. It has the double collars (known as cingulum) around the top of the cell, and a further wing (known as the sulcus) running vertically down the cell. It is oblong in shape with almost entirely rounded posterior end, but the tip of the end is slightly pointed. The size ranges from 54 to 94 µm in length and 43 to 60 µm in dorso-ventral width, with the widest region below the middle. The small epitheca is composed of four plates. It is low, flat or weakly convex, and is invisible in lateral view, which is a good identifying feature. The sulcus consists of several irregularly-shaped plates, and it contains the
flagellar pore. The hypotheca has four large plates that constitute the majority of the cell. The anterior two-thirds of the hypotheca has convex margins, while the posterior third forms a broad asymmetrical triangle with a straight dorsal edge, and occasionally a slightly concave ventral edge. Reproduction is by simple
binary fission. The most unusual cellular structure is the presence of numerous reddish-yellow
chloroplasts, which are derived from its prey, which in turn had acquired from algae.[5][6][7]
Diarrhetic shellfish poisoning
The first cases of diarrhetic shellfish poisoning (DSP) due to D. acuta were recorded in 1972 in
Peru, but were reported to the scientific community only in 1991.[8] It is a mildest form of seafood poisoning, indicated by severe diarrhoea.[1] The first toxins isolated from the species were pectenotoxins (PTX-2 and PTX-11) in 2003 from specimens collected from the west coast of
South Island,
New Zealand,[9] and PTX-12 independently at Skjer,
Sognefjorden in
Norway.[10] In 2004, the presence of
okadaic acidesters was reported.[11] Further identification and the importance of these compounds as causal factors of DSP were discovered in 2006.[2][3][4]
^
abMiles, Christopher O.; Wilkins, Alistair L.; Hawkes, Allan D.; Jensen, Dwayne J.; Cooney, Janine M.; Larsen, Kristofer; Petersen, Dirk; Rise, Frode; Beuzenberg, Veronica; Lincoln MacKenzie, A. (2006). "Isolation and identification of a cis-C8-diol-ester of okadaic acid from Dinophysis acuta in New Zealand". Toxicon. 48 (2): 195–203.
doi:
10.1016/j.toxicon.2006.04.018.
PMID16784765.
^
abMiles, Christopher Owen; Wilkins, Alistair L.; Hawkes, Allan D.; Jensen, Dwayne J.; Selwood, Andrew I.; Beuzenberg, Veronica; Lincoln MacKenzie, A.; Cooney, Janine M.; Holland, Patrick T. (Aug 2006). "Isolation and identification of pectenotoxins-13 and -14 from Dinophysis acuta in New Zealand". Toxicon. 48 (2): 152–159.
doi:
10.1016/j.toxicon.2006.04.005.
PMID16828828.
^
abSuzuki, Toshiyuki; Walter, John A.; LeBlanc, Patricia; MacKinnon, Shawna; Miles, Christopher O.; Wilkins, Alistair L.; Munday, Rex; Beuzenberg, Veronica; MacKenzie, A. Lincoln; Jensen, Dwayne J.; Cooney, Janine M.; Quilliam, Michael A. (2006). "Identification of pectenotoxin-11 as 34S-hydroxypectenotoxin-2, a new pectenotoxin analogue in the toxic dinoflagellate Dinophysis acuta from New Zealand". Chemical Research in Toxicology. 19 (2): 310–318.
doi:
10.1021/tx050240y.
PMID16485908.
^Lassus, P.; Seguel, M.; Truquet, P. (1998). "Morphological study of atypical Dinophysis acuta Ehrenberg from Chilean coastal waters by a digital pattern-recognition system". Botanica Marina. 41 (1–6): 435–441.
doi:
10.1515/botm.1998.41.1-6.435.
S2CID85769394.
^Lembeye, G; Yasumoto, T; Zhao, J; Fernandez, R (1993).
"DSP outbreak in Chilean Fiords". In Smayda, Theodore J; Shimizu, Yuzuru (eds.). Toxic phytoplankton blooms in the sea. Amsterdam: Elsevier Science Publishers. pp. 525–529.
ISBN9780444897190.
^Suzuki, T; Beuzenberg, V; Mackenzie, L; Quilliam, MA (2003). "Liquid chromatography-mass spectrometry of spiroketal stereoisomers of pectenotoxins and the analysis of novel pectenotoxin isomers in the toxic dinoflagellate Dinophysis acuta from New Zealand". Journal of Chromatography A. 992 (1–2): 141–50.
doi:
10.1016/s0021-9673(03)00324-8.
PMID12735470.
^Miles, Christopher O.; Wilkins, Alistair L.; Samdal, Ingunn A.; Sandvik, Morten; Petersen, Dirk; Quilliam, Michael A.; Naustvoll, Lars J.; Rundberget, Thomas; Torgersen, Trine; Hovgaard, Peter; Jensen, Dwayne J.; Cooney, Janine M. (2003). "A novel pectenotoxin, PTX-12, in Dinophysis spp. and shellfish from Norway". Chemical Research in Toxicology. 17 (11): 1423–1433.
doi:
10.1021/tx049870a.
PMID15540940.
^Suzuki, T.; Beuzenberg, V.; Mackenzie, L.; Quilliam, M. A. (2004). "Discovery of okadaic acid esters in the toxic dinoflagellate Dinophysis acuta from New Zealand using liquid chromatography/tandem mass spectrometry". Rapid Communications in Mass Spectrometry. 18 (10): 1131–1138.
Bibcode:
2004RCMS...18.1131S.
doi:
10.1002/rcm.1455.
PMID15150838.