Prorocentrum micans

Jin Q, Dong SL, Wang CY (2005) Allelopathic growth inhibition of Prorocentrum micans (Dinophyta) by Ulva pertusa and Ulva linza (Chlorophyta) in laboratory cultures. Eur J Phycol 40 31-37... 

Figure 2. Release of DMS by Prorocentrum micans in culture. Experiments were conducted in 1-liter glass bottles with silicone rubber stoppers and with a phytoplankton cell density of 500 cells/mL. The bottles were placed on a rotator (2 rev/min) in low light (2-30 peinstein/m2 sec). DMS increase in the headspace was measured by gas chromatograpny/flame photometric detector. A linear regression of the data yields a DMS production rate of 2.1 x 10 10 pmol/cell day, corresponding to a DMSP turnover of 026%/day.

DMS production by another dinoflagellate, Prorocentrum micans, also occurs at a rate of 0.3% of DMSP per day. 

SQ, , ,) Centrophages hamatus grazing on Prorocentrum micans X and A) P. micans alone. Experimental conditions as for Figure 2 phytoplankon 500 cells/mL) except zooplankton (40/L) added. DMS production is accelerated when the phytoplankton are ingested by zooplankton. However, when experiments are run for extended time intervals, DMS disappears from solution, presumably by microbial oxidation. At the end of this experiment, zooplankton had grazed the phytoplankton to veiy low levels, and oxidation of DMS that had been created in the process has resulted in a net accumulation of less DMS than in the phytoplankton-alone treatments. 

Lesser, M. P, Acclimation of phytoplankton to UV-B radiation — oxidative stress and photoinhibition of photosynthesis are not prevented by UV-absorbing compounds in the dinoflagellate Prorocentrum micans, Mar. Ecol. Prog. Ser., 132, 287, 1996. 

Uchida T (1977) Excretion of a diatom inhibitory substance by Prorocentrum micans Ehrenberg. Jap J Ecol 27 1-4... 

Uchida, T. (1976). Extretion of ammonium by Prorocentrum micans Ehrenberg in urea-grown cultures. Jpn.J. Ecol. 26, 43—44. 

Alternatively, zooplankton may increase N and protein ingestion rates to compensate for lower quality food (Darchambeau and Thys, 2005 Harris et al., 1986 Kleppel, 1983 Mayzaud et al., 1998 Plath and Boersma, 2001 Sterner and Hessen, 1994). Mayzaud et al. (1998) found A. tonsa copepod protein ingestion rates ranged from 4.2 tg protein ind h for live diatom prey (T. weissjlogii) and 4.5 tg protein ind h for hve dinoflageUate prey Prorocentrum micans), to 12.0 tg protein ind h ... 

M. Vernet, A. Neori, F.T. Haxo (1989). Spectral properties and photosynthetic action in red-tide populations of Prorocentrum micans and Gonyaulax polyedra. Mar. Biol., 103, 365-371. 

In a different connection, Aubert et al. (1967) have observed that, at some periods of the year and especially during spring, diatoms cease to synthesise antibacterial substances, a phenomenon which corresponds with the peak density of dinoflagellate populations. In vitro it has been shown that the proximity of Prorocentrum micans inhibits production of one of the antibacterial substances in Asterionella japonica (Aubert et al., 1970b). The substance released by the dinoflagellate which accounted for that effect was found to be proteinaceous with a very low threshold of activity 10 M (Aubert and Pesando, 1971 Aubert et al., 1972a). 

The multi-component biological system is more complex. Prorocentrum micans produces two antagonistic mediators (Fig. 5) one enhances the synthesis of carotenoid pigments in A. japonica and Chaetoceros lauderi, thus protecting their antibiotic fatty acids from in vivo photo-activation, and the second acts more probably on the bacterial cell, increasing the lethal effect of these antibiotics (Gauthier et al., 1978a). 

Fig. 5. Interactions between three marine microorganisms a dinoflagellate Prorocentrum micans), a diatom Asterionella japonica) and a bacterium (marine or terrestrial), involving four chemical telemediators TMC) TMCI and TMC2 are secondary mediators, the antibiotics of A. japonica being primary mediators.

Gauthier, M.J., Bernard, P. and Aubert, M., 1978a. Modification de la fonction antibio-tique de deux Diatomees marines, Astrionella japonica Cleve et Chaetoceros lauderi Ralfs par un dinoflagelle, Prorocentrum micans (Ehrenberg). J. Exp. Mar. Biol. Ecol., 33 37—50. 

The only report of such activity relates to halymecins (5-9). The microalgae concerned were Skeletonema costatum (at 10 Xg/ml), Oscillatoria amphibia (at 500 pg/ml), Brachiomonas submarina (at 67 Xg/ml) and Prorocentrum micans (at 67 pg/ml) [103]. This suggests that the toxins producted by marine fungi could, in particular, disturb aquacultural production when microalgae are used for feeding. 

Uchida, T. (1992) Alkaline phosphatase and nitrate reductase activities in Prorocentrum micans Ehrenberg. Bulletin of the Plankton Society of Japan 38, 85-92. 

Pinto, J.S. and SUva, E.S., The toxity of Cardium edule L. and its possible relation to the dinoflagellate Prorocentrum micans, Ehr. Notas Estud. Inst. Biol. Marit, 12, 1, 1956. 

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