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Volume 34, Issue 1
Displaying 1-6 of 6 articles from this issue
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Kyoko SHIOKAWA, Masayuki TAKAHASHI, Shun-ei ICHIMURA1973 Volume 34 Issue 1 Pages 1-11
Published: January 30, 1973
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSPhysiological adaptability of photosynthetic sulfur bacterium to low light environment and its ecological meaning were examined by using sulfur bacterium, Chromatium strain D. When Chromatium was cultured under 1 klux and 20 klux of continuous light, the high light culture showed a growth rate twice as high as that of the low light culture. The amount of bacteriochlorophyll in cells was also remarkably changed. The BChl content per unit cellular carbon or nitrogen was 2-3 times higher in the low light culture than in the high light culture. The carotenoid content per unit cellular nitrogen also showed the higher values in the higher light cultures. The light absorption of intact cells was influenced by the light conditions. The low light culture indicated a higher photosynthetic rate at low light intensities compared with the high light culture, and the photosynthetic rate based on cellular carbon was noticeably high for the low light culture. This may be due to the high content of BChl in a cell. By using the mathematical model, the depth-profiles of daily photosynthesis of both the low and high light cultures were estimated. The low light culture showed higher photosynthetic rates compared with the high light culture in the deeper layers where the light intensity is less than 10% of the surface illumination. The intensive growth of photosynthetic sulfur bacteria at the depth of dim light near the upper boundary of reductive zone may be supported by their photosynthetic adaptability to low light environment coupling with the occurrence of hydrogen donors such as H2S.View full abstractDownload PDF (1064K) -
Norizumi KITAGAWA1973 Volume 34 Issue 1 Pages 12-23
Published: January 30, 1973
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESS1. Five lakes, Kizaki-ko, Aoki-ko, Nakatsuna-ko, Nojiri-ko and Suwako, in Nagano Prefecture were investigated in 1972, in regard to their bottom fauna. The results obtained were compared with the data by MIYADI during the years from 1927 to 1930.
2. Lake Kizaki-ko : On the deep bottom Chironomus plumosus-b larva occurred abundantly, while Calopsectra sp. J occurred on the bottom shallower than 10m. Chaoborus larva was found on almost all over the bottom. According to MIYADI, Lake Kizaki-ko belongs to a “mesotrophic Sergentia lake”. At present, however, Sergentia (Endochironomus) larva which seems to be identical with Phaenopsectra is few in numbers, and Chironomus plumosus-b not recorded by MIYADI are found abundantly. Now-a-days, this lake seems to belong to a “eutrophic Plumosus lake”.
3. Lake Aoki-ko : Calopsectra sp. J larva, though not abundant, is distributed widely in this lake. MIYADI has pointed out this lake belongs to an “oligotrophic Tanytarsus lake”. At present Calopsectra sp. J is found only in winter and not in summer. Now Phaenopsectra sp. B-5 occurs not only in winter but also in summer, especially very abundant in the latter season.
4. Lake Nakatsuna-ko : Chironomus plumosus-b and Spaniotoma akamusi larvae were found all over the bottom, though not abundant, except the deepest zone. Some other kinds of Chironomidae larvae are distributed on the shallow bottom. MIYADI (1937) has designated this lake as a “Corethra lake” (=Chaoborus lake).
5. Lake Nojiri-ko : Chironomus plumosus-b-2 is the dominant species in this lake. Calopsectra sp. J, which occurred abundantly in MIYADI's paper, occurred scarcely. This lake has been pointed out by MIYADI in 1937 as a “mesotrophic Plumosus lake, ” but is a “eutrophic Plumosus lake” at present.
6. Lake Suwa-ko : Chironomus plumosus-b and Spaniotoma akamusi are the dominant species in this lake. Now Lake Suwa-ko may belong to a “polytrophic Plumosus-Akamusi lake”.
7. The types of bottom fauna of five Japanese lakes compared with MIYADI's data Are shown in Table 12.View full abstractDownload PDF (1344K) -
Yoshiyasu KANETSUNA1973 Volume 34 Issue 1 Pages 24-34
Published: January 30, 1973
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSThe writer has made a limnological investigation of five lakes and the rivers connecting with them in the Hokuriku district, with special reference to the relation between the salinity of the waters and the plankton species found there. The results obtained are as follows :
1. Forms of the waters
A. Lakes
1) Kahoku-gata…Mesohaline water
2) Kita-gata…Fresh water-polyhaline water
3) Imae-gata…Oligohaline water
4) Kiba-gata (south-west) Shibayama-gata…Fresh water
B. Rivers a. Kakehashi-gawa
1) at Sumiyoshi-bashi…α Mesohaline water
2) at Shiodome-bashi at Mukaimotoori-shinbashi…Oligohaline water b. Kushi-gawa
3) Muramatsu-cho…Fresh water-oligohaline water c. Shinhori-kawa
4) at Genpei-bashi at Shiodome-suimon…Fresh water
2. Plankton
The plankton consist of 151 species, 20 Rotifera, 2 Cladocera, 6 Copepoda, 1 Bryozoa, 13 Protozoa, 31 Chlorophyceae, 3 Chyanophyceae and 75 Diatomaceae.
The dominant and subdominant species occurring in this district are Sinocalanus tenellus, Paracyclopina nana, Pseudodiaptomus inopinus, Diaphanosoma brachyurum, Thermocyclops taihokuensis, Bosminopsis deitersi, Keratella valga, Brachionus calyciflorus var. dorcas and Ceratium hirundinella.
Generally speaking, the plankton fauna in these waters, are divided into two groups according to the main representatives. One consists of Paracyclopina nana and Sinocalanus tenellus in L. Kahoku-gata and L. Kita-gata, both of which have the water of high salinity, and the other is represented by Diaphanosoma brachyurum, Bosminopsis deitersi and Thermocyclops taihokuensis in the water of low salinity, such as, L. Kiba-gata, L. Imae-gata and L. Shibayama-gata.
As seen from the tables the zooplankton in the waters in question are richer in quantity than the scanty, phytoplankton, thongh the latter is rich in the number of species.
Among the phytoplankton, Merismopedia sp., Anabaena sp., Pediastrum tetras, Ankistrodesmus falcatus var. mirabilis, Schroederia setigera, Scenedesmus dimorphus, S. denticulatus, S. longispina, S. maximus, Actinastrum sp., and Coelastrum sphaericum seem to adapt to brackish water.
The diatoms are widely distributed in this district. The representative species found at Yoshizaki of L. Kita-gata is Melosira octogona and that at the Shiodome-bashi of the Kakehashi-gawa River is Nitzschia obtusa and N. obtusa var. scalpelliformis; that at Katayamazu by L. Shibayam-agata is Melosira varians. None of representative species is found in the other stations.View full abstractDownload PDF (1169K) -
Shoji CHIBA1973 Volume 34 Issue 1 Pages 35-40
Published: January 30, 1973
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSSucceeding to the investigations in 1962 and 1963, the author has carried on the limnological investigations of the Ono Reservoir nine times in 1964. This report deals with vertical distributions of water temperature, the pH values, the amounts of dissolved oxygen and the plankton in the water. The results are as follows :
No epilimnion developed in summer, a slight metalimnion being recognized just below the water surface. In September, however, a thin epilimnion developed down to the depth of two meters.
In autumn and winter, the dissolved oxygen was measured in about equal amount from the surface to the bottom, but it was especially rich in February. In summer, the oxygen in the deeper layers decreased remarkably. In 1964 this phenomenon occurred already in June, earlier than in the preceding years (1962, 1963). On September 27, oxygen was found as much in the deeper layers as in the epilimnion. Both on June 21 and September 6 the oxygen a little increased in the layer shallower than 20 meter deep. This phenomenon seems to be due to the density current of cold inflowing river water after rain.
In 1964, the low pH value was measured in the hypolimnion in summer, as it was recognized in the two previous years, but it slightly increased on the bottom of the water as in 1962. The difference of pH was scarcely seen throughout the layers, except in summer. In winter it remained unchanged.
The zooplankton decreased, compared with the results of the previous years, in the number of species and in individual numbers. Their occurrence shows a tendency similar to that in the former years. Synchaeta pectinata occurred in a few numbers in the seasons other than in summer. Keratella cochlearis, Ploesoma truncatum, Polyarthra sp. were also fewer in individual numbers than in the previous two years, and the time of their appearance was somewhat different. In 1964 there was found Chonochiloides dossuarius, which appeared also in 1962 and not in 1963.
Only two species, of Cladocera, Bosmina longirostris and Bosminopsis deitersi were found. The time of appearance of the former differed from that in the previous two years. The individual numbers of Cyclops sp. decreased, the time of appearance being the same as in 1963.
Some species of phytoplankton regarding the time of their appearance and in the number of species as well as in individual numbers showed the same tendency as in 1962, 1963 and 1964, but others showed a different tendency in the time of their appearance.
In 1964 the following four species appeared for the first time : Pediastrum tetras, two species belonging to Scenedesmus and Staurastrum sp. The occurrence of three species of algae, Oscillatoria tenuis, Synedra ulna and Eudorina elegans suggest that the water of this artificial lake is rich in nutrient salts.View full abstractDownload PDF (527K) -
Kenji NAKA1973 Volume 34 Issue 1 Pages 41-43
Published: January 30, 1973
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSLake Biwa in Shiga Prefecture is, as is known, of an oligotrophic condition. The results of limnological observations made by the Shiga Pref. Fisheries Exp. Station for forty years since 1931 have shown that the amounts of oxygen dissolved in the deep water before the season of whole circulation have been changing as follows : 6.64cc/l in 1931, 5.26cc/l on the average from 1950-1959, 4.39cc/l on the average for nine years since 1931, and in 1969 the amount became the smallest value of 3.25cc/l. Such results suggest that there is a tendency to a progressed eutrophication of Lake Biwa during the past forty years.View full abstractDownload PDF (302K) -
1973 Volume 34 Issue 1 Pages 48
Published: 1973
Released on J-STAGE: October 21, 2009
JOURNAL FREE ACCESSDownload PDF (130K)
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