scholarly journals Active uptake of kleptoplastids by Dinophysis caudata from its ciliate prey Myrionecta rubra

2011 ◽  
Vol 62 (1) ◽  
pp. 99-108 ◽  
Author(s):  
S Minnhagen ◽  
M Kim ◽  
PS Salomon ◽  
W Yih ◽  
E Granéli ◽  
...  
Keyword(s):  
Active Uptake ◽  
Myrionecta Rubra

Active Uptake of Sodium by Softshell Turtles (Trionyx spinifer)

Science ◽  
1965 ◽  
Vol 149 (3679) ◽  
pp. 67-69 ◽  
Author(s):  
W. A. Dunson ◽  
R. D. Weymouth
Keyword(s):  
Active Uptake ◽  
Softshell Turtles

The Regulation of Calcium and Magnesium in the Brackish Water Polychaete Nereis Diversicolor O.F.M

1970 ◽  
Vol 53 (2) ◽  
pp. 425-443
Author(s):  
C. R. FLETCHER
Keyword(s):  
Brackish Water ◽  
Calcium Concentration ◽  
Sea Water ◽  
Calcium Influx ◽  
Coelomic Fluid ◽  
Nereis Diversicolor ◽  
Active Uptake ◽  
Calcium And Magnesium ◽  
Electrochemical Potentials

1. Nereis diversicolor tolerates changes in the concentration of calcium and magnesium in its coelomic fluid proportional to the concentrations in the medium between chlorosities of 100-1000 mM/kg of water. 2. In lower salinities both ions are maintained relatively constant providing that the ratios of these ions to chloride in the medium are similar to the ratios in sea water. 3. The ratio of the concentration of calcium in the coelomic fluid to the concentration in the medium is a function of the salinity of the medium but not of the calcium concentration. 4. Both calcium and magnesium are at lower electrochemical potentials in the coelomic fluid than in the medium, indicating that it is not necessary to invoke active uptake. 5. The rate of calcium influx is substantial. 6. In salinities below to mM of chloride/kg of water the urine must contain less calcium than the coelomic fluid. 7. The significance of these results is discussed.

scholarly journals A MULTI-SPECIES MICROALGAE BLOOM IN BAHIA DE LA PAZ, GULF OF CALIFORNIA, MEXICO (JUNE 2008)

2009 ◽  
Vol 24 (1) ◽  
pp. 15 ◽  
Author(s):  
I. Gárate-Lizárraga ◽  
C. J. Band-Schmidt ◽  
F. Aguirre-Bahena ◽  
T. Grayeb del Alamo
Keyword(s):  
Phytoplankton Biomass ◽  
Gulf Of California ◽  
Phytoplankton Community ◽  
Red Tide ◽  
Total Density ◽  
La Paz ◽  
Gyrodinium Instriatum ◽  
High Species Richness ◽  
Myrionecta Rubra ◽  
Ecological Importance

Red tide patches were observed in Bahía de La Paz in June 17 and 18 of 2008. According to temperature and wind data this bloom occurred under upwelling-like conditions. Examination of the red tide samples showed the ciliate Myrionecta rubra and the naked dinoflagellates Gyrodinium instriatum and Katodinium glaucum as the main species responsible for this bloom. Total density (microalgae and ciliate) at the sampling stations was similar on both days, varying from 4607 × 103 cells L-1 to 4976 × 103 cells L-1 on the first day, and from 4172 × 103 cells L-1 to 5024 × 103 cells L-1 on the second day. Phytoplankton biomass (chlorophyll a) observed during the first day of the bloom was 1.5 mg m-3. Dinoflagellates and diatoms were the most numerically important phytoplankton groups. The phytoplankton community showed a high species richness, particularly heterotrophic dinoflagellates and ebridians. The ecological importance of the heterotrophic component of naked dinoflagellates and the ebriids for this bay is discussed. Florecimiento multiespecífico de microalgas en la Bahía de La Paz, Golfo de California, México (Junio, 2008) Durante los días 17 y 18 de junio de 2008, se observó una marea roja en la Bahía de La Paz. De acuerdo con los datos de temperatura y de vientos, este florecimiento ocurrió bajo condiciones muy similares a las de una surgencia. El examen de las muestras de marea roja revelaron que el ciliado Myrionecta rubra y los dinoflagelados desnudos Gyrodinium instriatum y Katodinium glaucum fueron las principales especies responsables de esta proliferación. La densidad total (microalgas y ciliado) fue similar en ambos días, variando de 4607 × 103 céls L-1 a 4976 × 103 céls L-1 durante el primero y entre 4172 × 103 céls L-1 y 5024 × 103 céls L-1 el segundo día, respectivamente. La biomasa fitoplanctónica (clorofila a) medida durante el primer día del florecimiento fue de 1.5 mg m3. Los dinoflagelados y las diatomeas fueron los dos grupos del fitoplancton numéricamente más importantes. Se observó una comunidad fitoplanctónica con una alta riqueza de especies, particularmente de dinoflagelados y ebriidos heterotróficos. Se discute la importancia del componente heterotrófico de los dinoflagelados desnudos y ebriidos.

Highly Divergent SSU rRNA Genes Found in the Marine Ciliates Myrionecta rubra and Mesodinium pulex

Protist ◽  
2004 ◽  
Vol 155 (3) ◽  
pp. 347-359 ◽  
Author(s):  
Matthew D. Johnson ◽  
Torstein Tengs ◽  
David W. Oldach ◽  
Charles F. Delwiche ◽  
Diane K. Stoecker
Keyword(s):  
Rrna Genes ◽  
Ssu Rrna ◽  
Marine Ciliates ◽  
Myrionecta Rubra

Mesodinium rubrum (Myrionecta rubra) in an Antarctic brackish lake

1993 ◽  
Vol 128 (1) ◽  
pp. 57-64
Author(s):  
Stephen J. Perriss ◽  
Harvey J. Marchant
Keyword(s):  
Brackish Lake ◽  
Mesodinium Rubrum ◽  
Myrionecta Rubra

Ionic Regulation of the Baltic and Fresh-Water Races of the Isopod Mesidotea (Saduria) Entomon (L.)

1968 ◽  
Vol 48 (1) ◽  
pp. 141-158 ◽  
Author(s):  
P. C. CROGHAN ◽  
A. P. M. LOCKWOOD
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Concentration ◽  
Relative Volume ◽  
Ice Age ◽  
Ionic Regulation ◽  
Sodium Influx ◽  
Active Uptake ◽  
Concentrated Solution ◽  
The Baltic

1. The isopod Mesidotea entomon has colonized the Baltic and certain Swedish lakes since the end of the last Ice Age. 2. The ionic regulation of Baltic animals and fresh-water animals (L. Mälaren) has been compared. 3. It has been possible to adapt Baltic animals to very dilute media, but 5% Askö sea water (5.5 mM/l. Na) appears to be the limit of adaptation. The haemolymph sodium concentration of Baltic animals from the very dilute media was considerably lowered. 4. The haemolymph sodium concentration in Mälaren animals is high (250 mM/l. Na) and comparable with that in Baltic animals in much more concentrated solution. The haemolymph ionic ratios of the Baltic and freshwater animals are similar. The Cl:Na ratio rises slightly in the more concentrated haemolymph samples. 5. From the concentration of ions in the haemolymph and in the total body water, the relative volume of the haemolymph was calculated. Mälaren animals appear to have a much larger haemolymph volume. 6. The permeability of the animals was determined from the rate of loss of sodium into de-ionized water. The permeability of the Mälaren animals is considerably reduced compared to the Baltic animals. Permeability is not related to the medium to which the animals had been adapted. 7. The sodium influx was determined using 22Na. The rate of active uptake was calculated from this. The maximal rate of active uptake was similar in Baltic and Mälaren animals. The sodium concentration of the medium at which active uptake was half maximum (KM) was considerably lower in Malaren animals than in Baltic animals. 8. The evolution of Mesidotea as a fresh-water animal is interpreted as a result of a reduction in permeability of the external surfaces to NaCl and an increase in the affinity of the active transport mechanism enabling the animal to maintain the haemolymph NaCl concentration in a steady state in fresh water.

Sodium Balance in Eriocheir Sinensis (M. EDW.). The Adaptation of the Crustacea to Fresh Water

1961 ◽  
Vol 38 (1) ◽  
pp. 153-162
Author(s):  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Body Surface ◽  
Eriocheir Sinensis ◽  
Vital Role ◽  
The Body ◽  
Sodium Balance ◽  
Progressive Reduction ◽  
Uptake Mechanism ◽  
Active Uptake ◽  
Main Factors

1. In Eriocheir sinensis active uptake of sodium plays a vital role in the maintenance of sodium balance. At external concentrations down to about 6 mM./l. the active uptake mechanism is fully saturated and the uptake rate just balances the rate of loss, which occurs primarily through the body surface. At lower external concentrations balance may be achieved, at least in part, by the activation of the uptake mechanism. 2. A hypothesis is put forward to account for the mechanism of adaptation of the Crustacea to fresh water. Two main factors are involved: (a) a progressive reduction in the permeability of the body surface to salts and, (b) the acquisition of an active uptake mechanism with a high affinity for the ions which it transports. 3. This hypothesis is discussed in relation to previous theories on the adaptation of the Crustacea to fresh water.

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