Morphology, ultrastructure and taxonomy of the raphidophycean algaHeterosigma akashiwo

Hara, Yoshiaki; Chihara, Mitsuo

doi:10.1007/bf02488320

Cited by 106 publications

(78 citation statements)

References 8 publications

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“…Discrimination of the mitochondrial from other multimembrane structures was difficult. Hara & Chihara (1987) reported similar results for the ultrastructural studies of H. akashiwo. Hence, it should be noted that morphological damage might be easily caused by chemical fixation (Plattnerr & Zingsheim 1983).…”

Section: Resultssupporting

confidence: 75%

Ultrastructural observation of natural field phytoplankton cells by using rapid freezing and freeze substitution

Kimura

Tomaru

Nagasaki

2012

Plankton Benthos Res

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Transmission electron microscopy (TEM) is a basic technique used to study the ultrastructures of phytoplankton. However, the use of chemical fixation to prepare phytoplankton samples for TEM is laborious and timeconsuming. Furthermore, chemical fixation often causes artificial structural changes (artifacts) in phytoplankton cells. In this study, we induced and optimized a rapid freezing and freeze substitution (RFS) method, accompanied by a filter dehydration system, to prepare TEM samples of marine microalgae, including Heterosigma akashiwo, Chattonella antiqua (Raphidophyceae), Heterocapsa circularisquama (Dinophyceae), Chaetoceros tenuissimus (Bacillariophyceae), and Teleaulax amphioxeia (Cryptophyceae). The whole procedure was much more efficient than the traditional method. In addition, the fine structure of each microalgal cell was well preserved. For example, the fine structures of the nuclear membrane, nuclear pores, and several vesicles were clearly observed, which were comparatively difficult to observe using the chemical fixation method. In addition, this new technique was applicable to the natural blooming cells of H. akashiwo, and high-resolution ultrastructural images were successfully observed. This is the first report on the application of the modified-RFS method for natural phytoplankton assemblages. This method can be used for diverse phytoplankters in natural waters, and the high-quality observations are expected to provide useful information toward understanding phytoplankter physiology and ecology.

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Section: Resultssupporting

confidence: 75%

Ultrastructural observation of natural field phytoplankton cells by using rapid freezing and freeze substitution

Kimura

Tomaru

Nagasaki

2012

Plankton Benthos Res

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“…Raphidophytes have a very high number of chloroplasts (e.g. Hara & Chihara 1987) and thus under light or epifluorescence microscopy, it is difficult to find openings on the raphidophyte cell body. Using a transmission electron microscope (TEM), raphidophytes have been observed to have 2 types of possible openings: (1) a funnel-shaped groove with 2 flagellae, and (2) mucocysts, which look like small openings when viewed from outside the cell surface (Vesk & Moestrup 1987).…”

Section: Open Pen Access Ccessmentioning

confidence: 99%

Feeding by raphidophytes on the cyanobacterium Synechococcus sp.

Jeong¹,

Seong²,

Kang³

et al. 2010

Aquat. Microb. Ecol.

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“…Olisthodiscus luteus and Heterosigma carterae; Hara & Chihara 1987, Throndsen 1996 have caused massive deaths of penned fish in numerous Pacific Rim countries, including the United States, Chile, Japan, Korea and New Zealand (Honjo 1993, Horner et al 1997, Khan et al 1997, and references therein). The mechanism of ichthyotoxicity is not well understood (see below), although toxicity level has been related to environmental conditions (salinity, irradiance, temperature) and growth stage (Ono et al 2000, Haque & Onoue 2002.…”

Section: Blooms Of H Akashiwo (Formerly Referred To Asmentioning

confidence: 99%

Effects of Heterosigma akashiwo (Raphidophyceae) on protist grazers: laboratory experiments with ciliates and heterotrophic dinoflagellates

Clough¹,

Strom²

2005

Aquat. Microb. Ecol.

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Morphology, ultrastructure and taxonomy of the raphidophycean algaHeterosigma akashiwo

Cited by 106 publications

References 8 publications

Ultrastructural observation of natural field phytoplankton cells by using rapid freezing and freeze substitution

Ultrastructural observation of natural field phytoplankton cells by using rapid freezing and freeze substitution

Feeding by raphidophytes on the cyanobacterium Synechococcus sp.

Effects of Heterosigma akashiwo (Raphidophyceae) on protist grazers: laboratory experiments with ciliates and heterotrophic dinoflagellates

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