Growth rates of<i>Heterophrys marina</i>(heliozoa) on<i>Chrysochromulina polylepis</i>(prymnesiophyceae)

Tobiesen, August

doi:10.1080/00785326.1991.10429711

Cited by 21 publications

(16 citation statements)

References 9 publications

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“…Toxic effects on protist grazers have also been observed with the ichthyotoxic Chrysochromulin polylepis (Tobiesen 1991). Excreted toxins produced by P. parvum also decrease egg production in the copepod Acartia clausi, which does not feed on P. parvum (Nejstgaard & Solberg 1996).…”

Section: Discussionmentioning

confidence: 77%

Relative importance of the different negative effects of the toxic haptophyte Prymnesium parvum on Rhodomonas salina and Brachionus plicatilis

Barreiro¹,

Guisande²,

Maneiro³

et al. 2005

Aquat. Microb. Ecol.

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The aim of this study was to determine the relative importance of the different processes/mechanisms by which the toxic haptophyte Prymnesium parvum, cultured under different nutrient conditions, affects non-toxic phytoplankton competitors and microzooplankton grazers. P. parvum was cultured under steady-state growth in different nutrient conditions: nitrogen depleted (-N), phosphorus depleted (-P) and balanced nitrogen and phosphorus (+NP). Cells from each nutrient condition and culture cell-free filtrates, alone and combined with non-toxic prey (Rhodomonas salina), were used as food for the rotifer Brachionus plicatilis. An additional experiment was carried out to test the effect of P. parvum cells and culture cell-free filtrate on R. salina. The highest haemolytic activity values were achieved by -P P. parvum cultures, followed by -N. However, the negative effect of P. parvum on R. salina and rotifers did not correlate with haemolytic activity but with the number of P. parvum cells. -N-cultured P. parvum were the most toxic for both R. salina and rotifers, followed by +NP. Therefore, haemolytic activity is not a good indicator of the total potential toxicity of P. parvum. The growth rate of R. salina was negatively affected by cell-free filtrates but the effect of P. parvum predation was greater. Rotifers fed on both toxic and non-toxic algae, indicating that they did not select against the toxic alga. The P. parvum cell-free filtrate had an effect on B. plicatilis, although this was weak. B. plicatilis was also indirectly affected by P. parvum due to the negative effects of the toxic alga on their prey (R. salina). However, the greatest negative effect of P. parvum on the rotifers was due to ingestion of the toxic cells. Therefore, the phytoplankton competitor R. salina is more affected by P. parvum predation and the grazer B. plicatilis is more affected by ingestion of the toxic cells, the effects of excreted compounds being secondary.

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Section: Discussionmentioning

confidence: 77%

Relative importance of the different negative effects of the toxic haptophyte Prymnesium parvum on Rhodomonas salina and Brachionus plicatilis

Barreiro¹,

Guisande²,

Maneiro³

et al. 2005

Aquat. Microb. Ecol.

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“…Tobiesen (1991) desci-ibed growth rates bet:.ree~ 0.21 and 1 59 d-' for Heterophrys marina. In his laboratory experiments growth was impacted by prey species, prey concentration and temperature.…”

Section: Discussionmentioning

confidence: 99%

Seasonal and spatial variability of planktonic heliozoa in Lake Constance

Zimmermann¹,

Müller²,

Weisse

1996

Aquat. Microb. Ecol.

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Planktonic heliozoa were investigated at a mid-lake and an inshore station in Lake Constance (Germany) from April to November 1993. Integrated water samples were taken over 0 to 8 m and 8 to 20 m depth intervals at the deep mid-lake station and over 0 to 2 m depth at the shallow inshore station. Heliozoans were counted and identified to genus level in live samples. The following genera were identified: Actinophrys, Raphidocystis, Heterophrys, Chlarnydaster, Choanocystis, Raphidiophrys, and Pterocystis. Small heliozoans (10 to 20 pm, mainly Heterophrys and Choanocystis) generally dominated the con~n~unity in terms of abundance. Large genera (Actinophrys, Raphidocystis) were, however, the major contributors to total biovolume. Total cell concentrations remained below detection limits from April to mid-June. Maxima of up to 6.6 ind. ml-' were observed in summer; smaller peaks occurred in autumn. Heliozoan cell numbers were significantly positively correlated w t h chlorophyll a concentration close to the surface. Negative trends were found in relation to potential heliozoan competitors or predators such as rotifers and crustacea. Community biovolumes of u p to 60 mm3 m-3 were recorded in mid-summer The seasonal succession of the dominant genera was sirnilar at both stations. The vertical distribution of heliozoans, examined on 2 occasions in summer and autumn, was positively correlated with chlorophyll a and temperature. We further studied the horizontal distribution of heliozoans at 8 stations across the northwestern part of Lake Constance on one occasion in late summer. Cell numbers recorded varied by a factor of 2. In situ growth rates of heliozoans were measured in diffusion chambers after the exclusion of larger potential predators at the mid-lake station on 2 occasions. Growth rates of distinct genera ranged from 0.06 to 0.59 d-l, community growth rates from 0 3 to 0.5 d.' Based on growth rates and biomasses, we calculated the potential heliozoan production Results suggest that during periods of their maximum abundance heliozoan community production is similar to average production estimates of ciliates and heterotrophic nanoflagellates. The seasonal mean heliozoan production is, however, equ~valent to only about 1 % of the combined ciliate and flagellate production.

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“…The bloom of C. polylepis in 1988 was almost monospecific at its peak occurrence and the abundance of zooplankton (copepods, heterotrophic protists) was very low (Nielsen et al 1990). Field and laboratory experiments demonstrated that C. polylepis inhibited the activity of planktonic bacteria, heterotrophic protists, and copepods (Nielsen et al 1990, Tobisen 1991). Experiments were not carried out on the interaction between Chrysochromulina polylepis and co-occurring planktonic algae during the bloom.…”

Section: Introductionmentioning

confidence: 99%

Allelopathy in the prymnesiophyte Chrysochromulina polylepis: effect of cell concentration, growth phase and pH

Schmidt¹,

Hansen²

2001

Mar. Ecol. Prog. Ser.

162

145

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Seven species (8 isolates) of dinoflagellates were exposed to a dense Chrysochromulina polylepis suspension. All species (with 1 exception) lost their motility, indicating that C. polylepis produces toxins, allelochemicals which affect other algae. The role of cell concentration, growth phase, and pH in the ability of C. polylepis to immobilize the dinoflagellate Heterocapsa triquetra was studied in batch cultures. Loss of motility of H. triquetra cells could be detected at cell concentrations of C. polylepis above 3 × 10 4 cells ml -1 . Senescent cultures of C. polylepis did not immobilize H. triquetra cells. The ability of C. polylepis to immobilize H. triquetra cells was dependent on the pH of the growth medium. More non-motile H. triquetra cells were obtained in alkaline growth medium than in neutral or acidic media. Growth interactions between C. polylepis and 15 species (16 isolates) were also studied in mixed batch cultures using a nutrient replete growth medium. The algae selected for these experiments included diatoms, dinoflagellates, silicoflagellates, raphidophytes, euglenophytes, cryptophytes, and prasinophytes. C. polylepis had a harmful effect on all the tested algae, except the dinoflagellate Prorocentrum minimum. The harmful effect of C. polylepis was observed as an initial decrease in growth rate of the tested algae, followed by a decline in their population numbers. The harmful effect of C. polylepis on the tested algae could in a few cases be ascribed to the high pH in the culture medium. In most cases, however, the harmful effect was observed at a pH which did not affect the growth of these species when they were grown in monoculture. This indicates that toxins released by C. polylepis had a harmful effect on most of the tested algae in the mixed cultures. KEY WORDS: Allelopathy · Toxicity · Growth phase · pH · Chrysochromulina polylepisResale or republication not permitted without written consent of the publisher

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Growth rates ofHeterophrys marina(heliozoa) onChrysochromulina polylepis(prymnesiophyceae)

Cited by 21 publications

References 9 publications

Relative importance of the different negative effects of the toxic haptophyte Prymnesium parvum on Rhodomonas salina and Brachionus plicatilis

Relative importance of the different negative effects of the toxic haptophyte Prymnesium parvum on Rhodomonas salina and Brachionus plicatilis

Seasonal and spatial variability of planktonic heliozoa in Lake Constance

Allelopathy in the prymnesiophyte Chrysochromulina polylepis: effect of cell concentration, growth phase and pH

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