EXPERIMENTAL OBSERVATIONS ON THE FLOTATION OF MARINE DIATOMS. II. SKELETONEMA COSTATUM AND RHIZOSOLENIA SETIGERA

1966 ◽  
Vol 11 (1) ◽  
pp. 18-34 ◽  
Author(s):  
Theodore J. Smayda ◽  
Brenda J. Boleyn
Keyword(s):  
Skeletonema Costatum ◽  
Marine Diatoms ◽  
Rhizosolenia Setigera

Influence of the Insecticide Diflubenzuron (Dimilin) on the Growth of Marine Diatoms and a Harpacticoid Copepod in Culture

1985 ◽  
Vol 42 (7) ◽  
pp. 1272-1277 ◽  
Author(s):  
N. J. Antia ◽  
P. J. Harrison ◽  
D. S. Sullivan ◽  
T. Bisalputra
Keyword(s):  
Skeletonema Costatum ◽  
Harpacticoid Copepod ◽  
Adult Survival ◽  
Thalassiosira Weissflogii ◽  
Marine Diatoms ◽  
Tigriopus Californicus ◽  
Per Se ◽  
Juvenile Development ◽  
Cyclotella Cryptica ◽  
Injurious Effects

Diflubenzuron (Dimilin) was tested, in the concentration range 0.1–5000 μg∙L−1, for possible injurious effects on the growth and photosynthesis of three chitin-producing (Thalassiosira weissflogii, T. norden-skioldii, Cyclotella cryptica) and one nonchitinaceous (Skeletonema costatum) diatoms. For comparison, the effects of the pesticide were also examined on adult survival and juvenile development of the harpacticoid copepod Tigriopus californicus. While the development of the copepod was hindered at concentrations of the order of 1–10 μg∙L−1, the diatoms were barely affected by Dimilin even at the highest concentration tested (5 mg∙L−1). We conclude that Dimilin acts specifically on insects and crustaceans as a larvicide by interfering with chitin deposition into cuticles during juvenile development through ecdysis. The lack of effect from Dimilin on the chitin-producing diatoms has suggested that the insecticide may not inhibit chitin biosynthesis per se as was previously believed, but that it presumably deregulates one or more of the larval postsynthetic processes responsible for chitin integration into cuticles.

Use of a Self-Cleaning, In-line Filter to Continuously Monitor Phytoplankton Nutrient Uptake Rates

1984 ◽  
Vol 41 (3) ◽  
pp. 540-544 ◽  
Author(s):  
J. S. Parslow ◽  
P. J. Harrison ◽  
P. A. Thompson
Keyword(s):  
Nutrient Uptake ◽  
Uptake Rate ◽  
Skeletonema Costatum ◽  
Thalassiosira Pseudonana ◽  
Ammonium Concentration ◽  
Marine Diatoms ◽  
Response Characteristics ◽  
Uptake Rates ◽  
Laboratory Cultures ◽  
Self Cleaning

Our new technique allows the decline in ambient ammonium concentration to be followed continuously during phytoplankton uptake experiments. A self-cleaning, in-line filter permits the continuous separation of cells from the medium for nutrient determination by an autoanalyzer. The technique works well with laboratory cultures of the marine diatoms Thalassiosira pseudonana and Skeletonema costatum. Changes in uptake rate on time scales of 1 min or longer can be resolved, the resolution being limited by the response characteristics of the autoanalyzer.

Photosynthetic Assimilation of 15N-Ammonia and 15N-Nitrate in the Marine Diatoms Bellerochea yucatanensis (von Stosch) and Skeletonema costatum

1981 ◽  
Vol 36 (9-10) ◽  
pp. 834-839 ◽  
Author(s):  
Günter Döhler ◽  
Hans-Jürgen Roßlenbroich
Keyword(s):  
Amino Acids ◽  
Growth Phase ◽  
Exponential Growth ◽  
Skeletonema Costatum ◽  
Exponential Growth Phase ◽  
Marine Diatoms ◽  
14Co2 Fixation ◽  
Photosynthetic Assimilation ◽  
Very High ◽  
Nitrogen Conditions

Abstract 14C-and 15N-Assimilation, 15N-Labelled Amino Acids, M arine D iatom s The marine diatoms Bellerochea yucatanensis and Skeletonema costatum were grown at +20 °C in 0.03 vol.% CO2 with nitrate or ammonia. The 15N -am m onia and 15N -nitrate assim ila­ tion and 15N -incorporation into various amino acids were studied of both diatom s during exponential growth phase in dependence of different nitrogen conditions. In all experiments the 15N -am m onia uptake was lower than the 15N -nitrate assim ilation rate up to 20-40 min photo­ synthesis. N itrate lim itation -cells grown in nitrate followed by growth in nitrogen-free m edium for 24 h — caused a strong 15N-label into aspartate after adding 15NH 4C1 (1 m M). In cells grown in nitrate highest enrichment of 15N was found in glutamine. Results were discussed with reference to the operating of the GS/GOGAT system and glutam ic acid dehydrogenase pathway. Photosynthetic 14CO2 fixation experiments showed a very high labelling of aspartate which was interpreted with a phosphoenolpyruvate carboxylation catalysed by phosphoenolpyruvate carb-oxykinase.

Pulsed laser irradiation impact on two marine diatoms Skeletonema costatum and Chaetoceros gracilis

2003 ◽  
Vol 37 (10) ◽  
pp. 2311-2316 ◽  
Author(s):  
Kanavillil Nandakumar ◽  
Hideki Obika ◽  
Tatsuya Shinozaki ◽  
Toshihiko Ooie ◽  
Akihiro Utsumi ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Skeletonema Costatum ◽  
Pulsed Laser ◽  
Marine Diatoms ◽  
Chaetoceros Gracilis ◽  
Pulsed Laser Irradiation
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