Effects of temperature and light on growth of the Antarctic algae Geminocarpus geminatus (Ectocarpales: Phaeophyceae) and Cladophora repens (Cladophorales: Cladophorophyceae) in culture

Phycologia ◽  
2006 ◽  
Vol 45 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Katherine A. McKamey ◽  
Charles D. Amsler
Keyword(s):  
Effects Of Temperature ◽  
The Antarctic ◽  
Antarctic Algae

scholarly journals PHYSIOLOGICAL AND BIOCHEMICAL CHANGES IN ALGAL CULTURES OF CHLORELLA VULGARIS AND SYNECHOCYSTIS SALINA (MESOPHILIC AND ANTARCTIC ISOLATES) OCCURING AFTER TREATMENT WITH UV-B RADIATION

2017 ◽  
pp. 73-82
Author(s):  
Dilyana Doneva ◽  
Juliana Ivanova ◽  
Lyudmila Kabaivanova
Keyword(s):  
Oxidative Stress ◽  
Chlorophyll A ◽  
Chlorella Vulgaris ◽  
Markers Of Oxidative Stress ◽  
Protective Strategies ◽  
The Antarctic ◽  
Antarctic Algae ◽  
Β Carotene ◽  
Stimulation Of

Determination of biomass production and viability of algal cells of Chlorella vulgaris and Synechocystis salina exposed to UV-B radiation were carried out in this study together with comparison of the mesophilic and antarctic isolates of both investigated strains. Estimation of the content of the pigments: chlorophyll a, chlorophyll b, β-carotene, C-phycocyanin and allo-phycocyanin in algal cells exposed to UV-B radiation was also accomplished. The obtained results showed that the antarctic algae are more resistant to oxidative stress than their mesophilic counterparts. The antarctic isolates of Ch. vulgaris and S. salina compared with the mesophilic ones - up to 72 h showed tolerance to low exposures of radiation, expressed in a slight stimulation of growth and viability of the cells. Antarctic isolates also showed greater resistance to low doses of UV-B radiation manifested by stimulation of the synthesis of chlorophyll a and β-carotene. The registered increase in the amount of C- and allo-phycocyanin in antarctic isolates of S. salina showed that they had developed protective strategies against UV-B radiation by increasing the concentration of the phycobiliproteins. As a result of increased UV-B background, in antarctic isolates, stronger antioxidant defence mechanisms are triggered, which proved the possibility of using them as markers of oxidative stress.

scholarly journals Polar gigantism and the oxygen–temperature hypothesis: a test of upper thermal limits to body size in Antarctic pycnogonids

2019 ◽  
Vol 286 (1900) ◽  
pp. 20190124 ◽  
Author(s):  
Caitlin M. Shishido ◽  
H. Arthur Woods ◽  
Steven J. Lane ◽  
Ming Wei A. Toh ◽  
Bret W. Tobalske ◽  
...  
Keyword(s):  
Body Size ◽  
Oxygen Supply ◽  
Elevated Temperatures ◽  
Metabolic Rates ◽  
Metabolic Demand ◽  
Thermal Limits ◽  
Highly Sensitive ◽  
Body Sizes ◽  
Effects Of Temperature ◽  
The Antarctic

The extreme and constant cold of the Southern Ocean has led to many unusual features of the Antarctic fauna. One of these, polar gigantism, is thought to have arisen from a combination of cold-driven low metabolic rates and high oxygen availability in the polar oceans (the ‘oxygen–temperature hypothesis'). If the oxygen–temperature hypothesis indeed underlies polar gigantism, then polar giants may be particularly susceptible to warming temperatures. We tested the effects of temperature on performance using two genera of giant Antarctic sea spiders (Pycnogonida), Colossendeis and Ammothea , across a range of body sizes. We tested performance at four temperatures spanning ambient (−1.8°C) to 9°C. Individuals from both genera were highly sensitive to elevated temperature, but we found no evidence that large-bodied pycnogonids were more affected by elevated temperatures than small individuals; thus, these results do not support the predictions of the oxygen–temperature hypothesis. When we compared two species, Colossendeis megalonyx and Ammothea glacialis , C. megalonyx maintained performance at considerably higher temperatures. Analysis of the cuticle showed that as body size increases, porosity increases as well, especially in C. megalonyx , which may compensate for the increasing metabolic demand and longer diffusion distances of larger animals by facilitating diffusive oxygen supply.

Aquatic primary production in the Antarctic

1977 ◽  
Vol 279 (963) ◽  
pp. 27-38 ◽  
Keyword(s):  
Southern Ocean ◽  
Primary Production ◽  
Freezing Point ◽  
Marine Phytoplankton ◽  
Nutrient Concentrations ◽  
Light Intensities ◽  
Ocean Productivity ◽  
Freshwater Habitats ◽  
The Antarctic ◽  
Antarctic Algae

A review is presented of studies, including recent work by members of the British Antarctic Survey, on the primary productivity of plankton, ice-flora and benthos in both marine and freshwater habitats in the Antarctic. Those members of the flora so far studied have low compensation points enabling slow growth in low light intensities but otherwise show no apparent adaptation to temperatures around freezing point. Certain sea areas, mostly inshore, have dense standing crops with daily and annual productivities as high as those of productive areas elsewhere in the oceans but in the open Southern Ocean productivity seems generally low even although nutrient concentrations are high, probably because of excessive turbulence carrying plankton out of the photic zone. There is as yet insufficient data to show whether, as a whole, the photosynthetic efficiency of the Southern Ocean is greater or less than that of other sea areas. Antarctic algae liberate extracellular products of photosynthesis but there is no definite evidence that these are reassimilated to support growth when light intensities are low and it may be that this material, carried by currents, supports heterotrophic production in other parts of the ocean. Comparison of data for adjacent marine and freshwater systems shows that their rates of primary production are much the same but the marine phytoplankton shows characteristics of shade-adapted cells consistent with the greater turbulence to which it is exposed.

scholarly journals The effects of temperature on the behaviour of the Antarctic sea star Odontaster validus

2010 ◽  
Vol 31 (3) ◽  
pp. 273-284 ◽  
Author(s):  
Anna Kidawa ◽  
Marta Potocka ◽  
Tomasz Janecki
Keyword(s):  
Motor Coordination ◽  
Keystone Species ◽  
Effect Of Temperature ◽  
Locomotory Activity ◽  
Measured Temperature ◽  
Sea Star ◽  
Sea Stars ◽  
Odontaster Validus ◽  
Effects Of Temperature ◽  
The Antarctic

The effects of temperature on the behaviour of the Antarctic sea starOdontaster validusMany Antarctic marine benthic invertebrates are adapted to specific environmental conditions (e.g.low stable temperatures, high salinity and oxygen content). Changes caused by global climatic shifts can be expected to have significant impact on their physiology and distribution.Odontaster validus, an ubiquitous, omnivorous sea star is one of the "keystone species" in the Antarctic benthic communities. Laboratory experiments were carried out to study the effect of temperature rise (from 0 to 5°C) on some vital biological functions that sea stars must perform in order to survive in their environment. Parameters such as behavioural reaction of sea stars to food and food odour, locomotory performance and ability to right were measured. Temperature increase significantly impaired the ability ofO. validusto perform these functions (e.g.lowering the number of sea stars able to right, increasing time-to-right, reducing locomotory activity, weakening chemosensory reaction to food and food odour). At temperatures of 4 and 5°C a loss of motor coordination was observed, although at all tested temperatures up to 5°C there were single individuals performing successfully.

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