THE EFFECT OF THE ULTRA-VIOLET COMPONENT OF THE SUN'S RADIATION UPON SOME AQUATIC ORGANISMS

Specimens of three species of fresh-water entomostracans—Daphnia pulex, Daphnia magna and Cypris reticulate—were each exposed to sunlight which had passed through filters which transmitted different regions of the solar spectrum. One filter ("Total") transmitted both visible and ultra-violet radiation, a second ("Novial") transmitted the visible only and a third ("U.V.") transmitted only the ultra-violet. By prolonged exposure the animals were killed under the Total and U.V. filters, while under the Novial they lived indefinitely. The chief point of interest lies in the comparison of the results obtained with these entomostracans which live in shallow pools with the results of previous experiments (2) on three marine entomostracans which remain at a considerable depth in the sea when the illumination is at all intense; the comparison shows that the former have a far greater resistance to the lethal effects of the sun's ultraviolet radiation. Developing embryos of the squid, Loligo pealii, were experimented upon in a similar manner; these embryos, which are enclosed in a gelatinous matrix attached to large algae in the intertidal zone, and, at low tide, are exposed to full sunlight, were extremely resistant to ultra-violet radiation.

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THE EFFECT OF THE ULTRA-VIOLET COMPONENT OF SUNLIGHT ON CERTAIN AQUATIC ORGANISMS

Canadian Journal of Research ◽

10.1139/cjr30-046 ◽

1930 ◽

Vol 3 (2) ◽

pp. 104-106 ◽

Cited By ~ 5

Author(s):

A. Brooker Klugh

Keyword(s):

Solar Spectrum ◽

Ultra Violet ◽

Aquatic Organisms ◽

Anguilla Rostrata ◽

Marked Contrast ◽

The Third ◽

Ultra Violet Radiation ◽

Short Time ◽

Considerable Depth ◽

Violet Radiation

In these experiments, which are a continuation of work carried out in 1927 and 1928, certain aquatic animals were exposed to sunlight behind filters which transmitted different regions of the solar spectrum. The first filter transmitted both the visible and ultra-violet regions, the second the visible only and the third the ultra-violet only. Young eels, Anguilla rostrata, which are in shallow water when ascending the streams, an Amphipod, Gammarus locusta, which was taken from shallow tide-pools, and a Ctenophore, Bolinopsis infundibulum, which floats about at the surface of the sea, all proved to be very resistant to ultra-violet radiation, thus showing a marked contrast to those animals which remain at some considerable depth in the sea or which come to the surface only when the illumination is very weak, as the latter are killed in a short time by exposure to ultra-violet radiation.

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Measurements of the sun’s ultra-violet radiation and its absorption in the earth’s atmosphere

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1923.0107 ◽

1923 ◽

Vol 104 (725) ◽

pp. 252-271 ◽

Cited By ~ 2

Keyword(s):

Wave Length ◽

Solar Spectrum ◽

Ultra Violet ◽

Upper Atmosphere ◽

Stray Light ◽

Solar Constant ◽

Absorption Bands ◽

Ultra Violet Radiation ◽

Short Period ◽

Violet Radiation

1. It is now well known that a connection exists between the variations in solar phenomena and changes in terrestrial weather. Thus the occurrence of an eleven-year cycle in the earth’s temperature, rainfall, etc., which is coincident with the eleven-year period of sunspots has long been recognised. More recently a marked connection has been found between the irregular short -period variations also. In this connection the work of H. H. Clayton, of the Argentine Meteorological Service, may be particularly mentioned. He has found that a very definite connection exists between the variations of the “solar constant,” as measured by the Smithsonian Astrophysical Department, and the temperature and rainfall some few days later in South America. The causes which lead to this connection are at present not known, though various theories have been proposed. For example, it has been suggested that the short wave-length radiation from the sun will produce ozone from oxygen in the upper atmosphere, and owing to the absorption bands of ozone both in the infra-red and ultra-violet, a change in the amount of this gas might change the radiation equilibrium temperature of the upper atmosphere, and so affect the pressure and temperature of the air below. The measurements of ultra-violet radiation made during “solar constant” determinations by the Smithsonian Institute are very uncertain, owing to the relatively small energy in this part of the solar spectrum, and the large errors due to stray light in the spectrometer. Since the measurements here described were started, Fabry and Buisson have published measurements of the amount of ozone in the atmosphere—measured spectroscopically—but only for about a dozen days.

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THE EFFECT OF THE ULTRA-VIOLET COMPONENT OF SUNLIGHT ON CERTAIN AQUATIC ORGANISMS III

Canadian Journal of Research ◽

10.1139/cjr31-032 ◽

1931 ◽

Vol 4 (5) ◽

pp. 483-486

Author(s):

A. Brooker Klugh

Keyword(s):

Ultra Violet ◽

Aquatic Organisms ◽

Aurelia Aurita ◽

Visible Radiation ◽

Biological Station ◽

The Third ◽

Ultra Violet Radiation ◽

Asterias Vulgaris ◽

Violet Radiation ◽

Quartz Tubes

The work reported in this paper is a continuation of the experiments carried out in 1927, 1928 and 1929 at the Atlantic Biological Station. The animals experimented upon were placed in three quartz tubes which were placed in a three-compartment box, each compartment receiving only the light which passed through the filter in the front of the compartment. The animals in the first compartment received only visible radiation, those in the second compartment received both visible and ultra-violet radiation, and those in the third compartment received only ultra-violet radiation and a little of the extreme violet. Young starfishes, Asterias vulgaris, were found not to be affected by ultra-violet radiation. The nudibranch, Eolis gymnota, which occurs at depths from seven to ten metres, proved sensitive to ultra-violet. The little thin-shelled mollusc, Yoldia sapotilla, was found to be affected injuriously by ultra-violet, while the amphipod Hyperia galba which has the peculiar habit of living in the cavity of the jellyfish, Aurelia aurita flavidula, proved to be resistant to ultra-violet radiation.

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