• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.2
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• pp.95-101
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• 2007

We investigated the growth and phosphate uptake of a toxic dinoflagellate, Gymnodinium catenatum, isolated from Yeosuhae Bay, South Korea. A short-term phosphate uptake experiment revealed that its maximum uptake and the half-saturation constant were 1.39 pmol/cell/hr and $2.65{\mu}M$, respectively. In a semicontinuous culture, the maximum specific growth rate and minimum phosphorus cell quota of G. catenatum were 0.39/day and 1.27 pmol/cell, respectively. Thus, G. catenatum is a poor competitor in terms of inorganic nutrient use and is unlikely to form blooms in Yeosuhae Bay.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.66-77
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• 1999

The sequences coding for the 5.8S rDNA and the internal transcribed spacers (ITS1 and ITS 2) from the isolates of nine isolates of Gyrodinium impudicum and two isolates of Gymnodinium sanguineum species were amplified, sequenced and compared with the previously known Alexandrium species and Gymnodinium catenatum. The genetic distance analyses based on the sequence alignment indicated that Gymnodinium catenatum and Gyrodinium impudicum species were some related, Alexandrium species was distant. G. catenatum and G. sanguineum were quite separate, but these two species belonged to the same genus. G. impudicum and G. catenatum forming the closet cluster showed some variation in the alignment of ITS regions. The length of ITS1 varied more than that of ITS2 and the length of ITS1 and ITS2 was different for each G. impudicum, Gymnodinium and Alexandrium species. Also, the length of ITS1 was shorter than that of ITS2. However, on the sequences of G. sanguineum, the length of ITS1 was longer about 23 nucleotides than that of ITS2. The phylogenetic analysis and rDNA similarity of G. impudicum and G. catenatum $(59\%)$ is higher than the that of G. catenatum and G. sanguineum $(55\%)$. It was thought that the phylogenetic analysis and the genetic distance revealed that G. impudicum and G. catenatum were clearly different species and G. impudicum may belong to the genus of Gymnodinium.

• Korean Journal of Environmental Biology
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• v.37 no.1
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• pp.31-41
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• 2019

The toxic dinoflagellate Gymnodinium catenatum isolated from the southern coast of Korea was described under light and scanning electron microscopy, and its large subunit (LSU) rDNA was sequenced. In addition, the effects of temperature and salinity on its growth were investigated. The cells of G. catenatum, as viewed under the electronic microscope, were green-brown color, $38.1-77.4{\mu}m$ in length and $26.1-40.8{\mu}m$ in width. The epicone was conical, while the hypocone was trapezoidal. The nucleus was located at the central part of the cell. The apical groove was horseshoe-shaped and small pores were irregularly distributed on the cell surface. Molecular phylogeny based on LSU rDNA gene sequences showed that the Korean G. catenatum and previously reported species formed a monophyletic clade within Gymnodinium sensu stricto clade. The maximum growth rate of $0.37day^{-1}$, was obtained at $25^{\circ}C$ and 35 psu, and the maximum cell density of $1,073cells\;mL^{-1}$, was observed at $20^{\circ}C$ and 25 psu. However, G. catenatum did not grow at temperature < $15^{\circ}C$ and < $30^{\circ}C$. These results suggest that environmental conditions of summer and autumn in the southern coast of Korea may be favorable for the growth of G. catenatum.

• Journal of Life Science
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• v.13 no.5
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• pp.651-657
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• 2003

Randomly amplified polymorphic DNA (RAPD) analysis was used to study genetic relationships among C. polykrikoides, G. impudicum and G. catenatum, which possess similar morphological features. Four of 12 primers were selected and 59 amplification products ranged from 0.2 kb to 3.0 kb. The number of polymorphic products in C. polykrikoides, G. impudicum and G. catenatum was 16 (27.1%), 8 (13.5%), and 16 (27.1%), respectively, while 17 were monomorphic. Number of species-specific bounds was 26 (44.0%), 34 (57.6%), 26 (44.0%) in C. polykrikoides, G. impudicum and G. catenatum, respectively. The genetic similarity between C. polykrikoides and G. impudicum/G. catenatum was 0.83, whereas G. impudicum and G. catenatum was 0.78. Our results suggest that C. polykrikoides, G. impudicum and G. catenatum are extremely different on the basis of RAPD analysis, despite similarity based on their morphology. The RAPD technique appears to be efficient in detecting genetic variation in these dinoflagellates.

• ALGAE
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• v.19 no.4
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• pp.293-301
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• 2004

A chain-forming toxic din flagellate, Gymnodinium catenatum (Graham) was known as a paralytic toxin-producer among Gymnodinoid group. In the study, the effects of water temperature, salinity and irradiance on the growth of G. catenatum isolated from Yeosuhae Bay, Korea were investigated. Water temperature range in which G. catenatum showed specific growth rate higher than 0.3 day$^{-1}$ were above about 18${^{\circ}C}$. However, salinity did not have such an effect on growth of G. catenatum. The maximum growth rate (0.5 day$^{-1}$) was obtained at 25${^{\circ}C}$ and 30 psu. The specific growth rate (u) expressed as a polynomial equation as functions of temperature (T; ${^{\circ}C}$) and salinity (S; psu) was $\mu$ = 0.005·T$^2$ - 0.0001164 T$^3$ - 0.063-S + 0.005-S$^2$ - 0.00007608-S$^3$ - 0.003-T-S + 0.00005308-T$^2$-S. Thus, in aspects of water temperature and salinity, the species may be expected to survive in most Korean coastal waters from early summer to autumn. The irradiance-growth curve was described as = 0.16 (I - 10.4)/(1 + 21.8) at 18${^{\circ}C}$ and 30 psu, indicating a half-saturation (Ks) photon flux density (PFD) of 42.6$\mu$mol m$^{-2}s^{-1}$ and compensation PFD (I$_0$) of 10.4$\mu$mol m$^{-2}s^{-1}$. These characteristic responses to irradiance suggest that G. catenatum can reside at the sub-surface.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.1
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• pp.39-49
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• 2007

Species competition among the toxic dinoflagellates Alexandrium tamarense and Gymnodinium catenatum and the diatom Skeletonema costatum was simulated using a mathematical model. Prior to the model simulation competition experiments using the three species were conducted to obtain data for validation by the simulation model. S. costatum dominated at a density of ${\sim}10^{4}\;cells/mL$ compared to the other species in the medium with dissolved inorganic phosphorus (DIP). The growth of S. costatum was also stimulated by the addition of dissolved organic phosphorus (DOP), such as uridine-5-monophosphate (UMP) or glycerophosphate (Glycero-P), although this species is unable to take up DOP. This implies that the growth of S. costatum may be supported by DIP, which is hydrolyzed by alkaline phosphatase produced from A. tamarense and G. catenatum. The species competition model was run assuming the environmental conditions of northern Hiroshima Bay, Japan, during spring and summer. G. catenatum increased in cell density and neared the level of S. costatum at the end of the calculation. In the sensitivity analyses by means of doubling and halving parameters, depleted DIP had little effect on the cell density of G. catenatum. However the growth of A. tamarense and S. costatum was significantly affected by changes in the parameter values. These results indicate that if DIP depletion is ongoing, species that have a large phosphate pool in their cells, such as G. catenatum, will predominate in the community.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.837-842
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• 1996

The resting cyst of Gymnodinium catenatum was found in the surface sediments collected from Chinhae Bay in October, 1991. This is the first record of the species in the Korean waters. The relative abundance was low with the maximum of $1.7\%$. The colonial motile form consisting of four cells was observed in 1992 from the excystment of the cyst collected from the Wonmun Bay in Chinhae Bay. No blooms caused by G. catenatum has been observed in Chinhae Bay during the survey.

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.30-37
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• 2006

We performed experiments on the uptake and excretion of dissolved organic phosphorus (DOP) using two toxic dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham, isolated from Hiroshima Bay, Japan. ATP (adenosine triphosphate), UMP (uridine-5-monophosphate), G-6-P (glucose-6-phosphate) and Glycero-P (glycerophosphate) were used as DOP sources in preliminary uptake experiments. ATP was selected as the DOP species for the short-tenn uptake experiment because preliminary experiments showed it to be the DOP source used by both species. Although the $K_s$ values of A. tamarense and G. catenatum (5.63 and $7.61{\mu}M$, respectively) obtained from the short-term experiments for ATP were only slightly higher than those reported for dissolved inorganic phosphorus (DIP), the ${\rho}_{max}$ values (5.04 pmol/cell/h and 13.4 pmol/cell/h, respectively) were much higher. The DOP excretion rate in batch-culture experiments was estimated at 0.084 pmol/cell/h for A. tamarense and 0.012 pmol/cell/h for G. catenatum, accounting for about 30% and 25%, respectively, of the assimilated phosphorus. Our results suggest that the DIP-depleted conditions of Hiroshima Bay favor these two species by supporting their ability to use DOP.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.198-199
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• 2000

유독 와편모조 Gymnodinium catenatum Graham은 인간과 해양동물에 마비성패독(PSP) 발생의 원인이 되는 신경독을 생산한다. 1976년에 스페인 북서쪽 해안에서 G. catenatum에 의한 PSP 발생이 처음으로 알려졌고(Estrada et al. 1984) 특히 호주와 스페인 등지에서 문제가 되고 있다. 한국에서도 1991년 10월 진해만에서 채집된 저질로부터 처음 휴면포자가 발견되었고, 휴면포자량은 전체 와편모조류 중 0.9~l.7%를 차지하였다(Kim et al., 1996). 1996년 9월에는 영양세포가 7,250 cells/$\ell$로 진해만의 수정리에서 출현하였고, 1997년 5월에는 550 cells/$\ell$로 출현하였다(김과 신, 1997). 이는 Alexandrium속이 주로 봄철에 대량발생을 하여 패류 독화가 문제되는 것에 반해 C. catenatum은 봄, 가을에 출현함으로써 봄철에 이어 가을철에도 패류독화가 문제될 수 있다는 것을 의미한다. 따라서 본 연구에서는 서해안 및 남해안에서 분리된 지역분리주의 PSP 생산성을 검증하고, 지역 개체군의 독조성을 비교하여 지역 독화의 가능성을 예측하고자 한다. (중략)

• Journal of fish pathology
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• v.16 no.3
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• pp.193-201
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• 2003

Mastoparan B (MPB), an antimicrobial cationic peptide isolated from the venom of the hornet Vespa basalis, is a basic amphipathic α-helical peptide composed of fourteen amino acid residues. In this study, we have investigated the algicidal effect of MPB against harmful algae blooms (HABs) casative Alexandrium tamarense, Chattonella marina, Cochlodinium polykrikoides and Gymnodinium catenatum. The algicidal effect of MPB showed in the concentration of 31.3 $\mu{g}$/mL to 500 $\mu{g}$/mL against 4 HAB species and observed cell lysis or cell ecdysis by microscopy. MPB reacted more sensitive to C. marina and C. polykrikoides than A. tamarense and G. catenatum. The algicidal study of MPB against HABs will provides much insight into development of new algicidal substances.