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Volume 47, Issue 1
Displaying 1-3 of 3 articles from this issue
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Tohru Ikeya, Kaori Ohki, Masayuki Takahashi, Yoshihiko Fujital1991 Volume 47 Issue 1 Pages 1-6
Published: February 25, 1991
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSPhotosynthetic pigment system of picophytoplankton of cyanophytes was examined with five strains isolated from the Kuroshio water at the depth of 70m. Examination was made for the absorption spectra of intact cells of each strain. Analysis of pigment composition was also made with Synechococcus NIBB 1059 and 1071, which were isolated from surface waters of the Gulf Stream and Kuroshio area, respectively. Results indicated that (1) all strains contain phycoerythrin with a very high concentration, and (2) the phycoerythrin in these strains contains two chromophores, phycoerythrobilin and phycourobilin, and (3) a large abundance of phycoerythrin and phycourobilin in the phycoerythrin enables Synechococcus picophytoplankton to absorb effectively the light in the blue-green region at the subsurface depth. These characteristics suggest that cyanophytes in the subsurface water can collectt the blue-green light and perform actively photosynthesis even at the bottom of euphotic layer.View full abstractDownload PDF (1166K) -
Tsutomu Ikeda1991 Volume 47 Issue 1 Pages 7-16
Published: February 25, 1991
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSUsing a growth model based on moult number, the assimilated carbon budget was constructed for Themisto japonica growing from the specimens just released from the marsupium to mature adults at 1-15°C. As budget parameters, growth (G), metabolism (Me), moult (Mo), and reproduction (Re) were measured and assimilation (A) was estimated as the sum of these four parameters (A=G+Me+Mo+Re). The results of the lifetime budget indicated that among these parameters the greatest allocation of A was to Me (70-83%). Lifetime expenditure of carbon for Me was the least at 7°C, and Me increased with either increase or decrease of the temperature from 7°C. A female grown to full adult size at 7°C invested 16.6% for G, 70.2% for Me, 2.1% for Mo, and 11.1% for Re 0f total A. General features seen in the partition of A to G, Me, Mo, and Re for T. japonica are similar to those of other planktonic crustaceans being reported. Considering the profound effect of temperature on the assimilated carbon budget, practical problems in defining the representative habitat temperature for diel vertical migrators like T. japonica in the field are discussed.View full abstractDownload PDF (1829K) -
Sei-ichi Kanari1991 Volume 47 Issue 1 Pages 17-25
Published: February 25, 1991
Released on J-STAGE: June 17, 2011
JOURNAL FREE ACCESSThis paper describes a free-fall micro-scale profiler (MSP) which can measure vertical profiles of microscale velocity shear, temperature gradient, and conductivity gradient of both fine and microscale ranges, together with the vertical profiles of temperature and conductivity. The measurable vertical scales of the microscale shear range from about 50cm to 2cm.
The MSP was designed to perform profiling to depths of 500m with a nominal fall speed of about 70cm sec-1. Retrieval of the instrument is accomplished by a 700m Kevlar string of 1.5mm in diameter wound on a portable winch, after ballast has been released at a preset depth by a mechanical rupture disk.
The results of sea trials show that the microscale shear spectrum nearly corresponds with the theoretical one derived on the assumption of homogeneous turbulence.View full abstractDownload PDF (1214K)
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