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Volume 63 (1997)
- Issue 6 Pages 877-
- Issue 5 Pages 665-
- Issue 4 Pages 522-
- Issue 3 Pages 317-
- Issue 2 Pages 145-
- Issue 1 Pages 3-
Volume 63, Issue 4
Displaying 1-17 of 17 articles from this issue
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Shoko Ishihara, Tadashi Kubota1997 Volume 63 Issue 4 Pages 522-530
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe stomach content of the lanternfish, Benthosema pterotum is analyzed based on 700 specimens caught during the daytime by an otter trawl in the East China Sea and the Yellow Sea in October 1989 and 1990.
The food items were mainly composed of zooplankton such as copepods, euphausiids, ostracods and chaetognaths. This composition of food items has changed with the area, year and body size range. The average stomach content index in weight was 0.91±0.9 and 0.88±0.7 in October 1989 and 1990, respectively.
Since B. pterotum is known to be a common prey organism of larger fishes of commercial value, this species is thought to play an important role as the third producer connecting second producers such as small crustaceans with much higher producers in the food web of the studied areas.View full abstractDownload PDF (645K) -
Yoichi Yoshida1997 Volume 63 Issue 4 Pages 531-536
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn the south basin of Lake Biwa, Microcystis aeruginosa dominantly occurred and the water blooms were formed at the limit area in late summer of 1983, 1987, 1988, 1990, and 1994. The relationship between the dominant occurrence of M. aeruginosa and water quality and the meteorological condition in the south basin of Lake Biwa was examined, referring to data from Shiga Prefecture and the meteorological Agency.
The changes of water quality in the south basin in early September of 1980-1994 showed a remarkable fluctuation of TP (total phosphorus), DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus), DIN:DIP, TN (total nitrogen):DIN, and TP:DIP ratios, and M. aeruginosa usually occurred in the water with comparatively low DIN:DIP ratio.
The comparison of each average water quality with the dominant species of phytoplanktons in early September of 1980-1994 showed that M. aeruginosa dominantly occurred in the waters with low DIN, DIP, and DIN:DIP ratio and high TN: DIN and TP:DIP ratios. The species occurred in the years with the meteorological conditions of high air temperature, long sunshine time, and comparatively low rainfall (precipitation) during August. These features of M. aeruginosa were contrasted remarkably with those of Rhodomonas sp.View full abstractDownload PDF (466K) -
Kouji Kooka, Tetsuya Takatsu, Yoshihiko Kamei, Toshikuni Nakatani, Toy ...1997 Volume 63 Issue 4 Pages 537-541
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe diet and feeding intensity of walleye pollock Theragra chalcogramma were investigated in April and October 1993, and in April 1994. Specimens ranging from 262 to 456mm in standard length were sampled with a mid-water trawl off Hiyama Subprefecture and Aomori Prefecture in the northern Japan Sea. The main food items were large-sized zooplankton. In April, pollock fed chiefly on euphausiids (Thysanoessa longipes), chaetognaths, and hyperiid amphipods (Themisto japonica). In October, the main food organisms were hyperiid amphipods (T. japonica). Stomach-content weight indices indicated that the feeding intensity of pollock was stronger in April (after spawning) than in October (before spawning). The numerical compositions of food categories in April differed among sampling stations. Such differences were not observed in October. It seems likely that the distinct variation of diets in April is ascribed to geographic differences in zooplankton composition in the mesopelagic zone.View full abstractDownload PDF (416K) -
Yongjun Tian, Makoto Shimizu1997 Volume 63 Issue 4 Pages 542-548
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSPopulation size and catchability coefficient of the cockle Fulvia mutica (Reeve) in Tokyo Bay were estimated using De Lury's method. Then, the present status of the stock was assessed based on the yield per recruitment theory of Beverton and Holt.
The population size (N0) and the catchability coefficient (q) were estimated as 39 to 788 (×104) in number and 0.58 to 2.85 (×10-3) per boat•day from 1978 to 1989, respectively. Annual fluctuations of N0 are corresponded with those of catches (C) and CPUE, and it shows that the stock is in a very unstable condition. Exploitation rate (C/N0) is between 0.4 to 0.9 and, in most years, it is over 0.6 and fishing effort is in a high level. Also the exploitation rate apparently increased with decrease of the catches, it has the inclination that the fishing effort gets stronger as the stock abundance is poorer. Isopleth diagram of catch yield per recruit (Y/R) shows that raising the age at first capture is more effective than increasing fishing effort to achieve the maximum yield per recruit and in keeping the stability of the stock.View full abstractDownload PDF (488K) -
Kangseok Hwang, Ichiro Aoki1997 Volume 63 Issue 4 Pages 549-556
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn this paper the supervised learning paradigm with three layered networks and backpropagation algorithm of artificial neural networks were used for forecasting catches of multiple species in set nets. Three-month means of CPUE of jack mackerel Trachurus japonicus, Japanese sardine Sardinops melanostictus, chub mackerel Scomberjaponicus and total catch for all species in set nets of the Seishyo region in Sagami Bay were collected as output vectors. The input vectors of oceanic conditions were the average temperature anomalies around the set nets and at the surface and 50m depth in Sagami Bay, the Kuroshio path type, and the distances of the Kuroshio current from Cape Irou-zaki and Cape Nojima-zaki. We examined four cases of networks considering fish species and fishing seasons. The CPUE of jack mackerel and total catch in the set nets can be predicted from those of the preceding period and oceanic conditions. Predictions using the same season data were more successful than those using the preceding seasons.View full abstractDownload PDF (590K) -
Yukio Agatsuma, Tadashi Kawai1997 Volume 63 Issue 4 Pages 557-562
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSSeasonal migration of the sea urchin Strongylocentrotus nudus between intertidal and subtidal zone were investigated from May 1994 through December 1995 in Oshoro Bay of southwestern Hokkaido, Japan. The over 1-year-old sea urchins over 20 min in test diameter remarkably showed seasonal migration in compliance with the request of algal foods. The sea urchins with the growing stage of gonads inhabit in crustose corallines dominated subtidal zone from April to July, because drift algae for foods were abundantly provided from intertidal zone where Laminaria religiosa dominated. The sea urchins migrated to search for algal foods to intertidal zone from July to October when their gonads were growing, pre-mature and/or mature stage, and to subtidal zone from November to March when their gonads were recovering stage due to run out of algal foods and to be affected by high wave action in an intertidal zone. The yearling sea urchins inhabited in subtidal zone throughout the year.View full abstractDownload PDF (494K) -
Minoru Takaba1997 Volume 63 Issue 4 Pages 563-569
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn order to examine the relationship between sea water temperature and annual growth of red sea bream caught in the waters around the Oosakikamishima Island in the middle of Seto Inland Sea, the body length was estimated when each annual ring was formed on a scale, then the calculated body length of each age group from 1980 to 1986 was compared. The calculated body length was obtained from the expression FLi=(FL-b)×ri/R+b. The total deviation of the water temperature was calculated using the average daily water temperature during the growing season from May to November. The annulus formation time was from May to July and differed with water temperature during winter. The annulus formation indicates the time when growth begins after winter. The equations estimated by the least squares method for annual growth at age I (years), say Δ1I(mm), and the total deviation of the water temperature (T: °C), were Δ10=118.8+0.6•T, Δ11=64.7+0.3•T, Δ12=46.2+0.3•T, and Δ13=36.5+0.2•T, which were statistically significant (p<0.01). The values of the regression coefficient decreased with age. Furthermore, a significant correlation was detected between temperature and the lengths at the annulus formation for ages 1 to 3 years old.View full abstractDownload PDF (421K) -
Chiharu Aoyama, Etuyuki Hamada, Masahiko Furusawa, Kiyotaka Saito1997 Volume 63 Issue 4 Pages 570-577
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn order to get reliable results from surveys by quantitative echo sounders, an accurate calibration of the sounder is necessary especially for the transmitting and receiving system. Therefore, we investigated a new method of simple and accurate calibration by utilizing the echoes from the water surface of an experimental water tank. We show that the method can easily calibrate the equivalent beam width of surface scattering by application of the property that the backscattering strength of the surface of water is 0dB. In case of a sharp beam, we show that the equivalent beam widths for surface scattering and volume scattering are nearly the same. Moreover, it is possible to perform an overall calibration of the transmitting and receiving system, including the equivalent beam width and the transmitting and receiving sensitivities, thus producing a more reliable result than the method in which each factor is measured separately.View full abstractDownload PDF (482K) -
Yuzo Iwata, Isao Sugahara, Toshio Kimura, Kom Silapajarn, Motohiro San ...1997 Volume 63 Issue 4 Pages 578-584
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSAlgal growth potential (AGP) of Gymnodinium mikimotoi was examined at a sampling station situated in Gokasho Bay during a red tide period from 1991 to 1994. In the year 1991, 1992 and 1994 when the bloom of G. mikimotoi occurred, the high AGP of seawater at the depth of 1.0m above bottom (B-1m) was observed at the order of 103 cells/ml before the peak of the algae. But the AGP didnot increase during the period from June to August in 1993, the year of no development of G. mikimotoi. These results indicate the possibility of predicting red tide by AGP of seawater at the depth of B-1m.
The growth limiting nutrients in Gokasho Bay were also studied using AGP assay. The growth yield of G. mikimotoi was enhanced by the addition of phosphorus to filtered seawater prior to development of the algae. When the bloom of G. mikimotoi occurred, the lack of phosphorus was not found. Therefore, it was suggested that the nutrient factor which control development of G. mikimotoi red tide was phosphorus.View full abstractDownload PDF (517K) -
Yongjun Tian, Makoto Shimizu1997 Volume 63 Issue 4 Pages 585-593
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSGrowth increment patterns of Fulvia mutica were examined, and were used in age determination.
Fine growth increments are visible both in the cross-sections of the shell and chondrophore. Growth increments in the shell run approximately parallel to the inner surface, while those in the chondrophore shows a concentric ring pattern like tree rings or fish otolith. It is easier to measure the latter than the former, because growth lines in the shell are too long to trace, and because the outer layer of the shell in which the growth increments are visible is too thin in the umbo. The growth increment in the chondrophore is considered more reliable in age determination.
Chondrophore growth is allometric with respect to shell height, and a high correlation between growth line number and chondrophore length has been confirmed. Given that one increment is formed daily, the growth of the cockle was estimated as a following formula,
SHt=110.33[1-exp{-1.86×10-3(t+43.87)}]
where SHt represents shell height in mm at age t in days. This result corresponded with the growth estimated from size frequency analysis. It is clear that growth increments in the chondrophore are useful in age determination of the cockle.View full abstractDownload PDF (2194K) -
Yoichi Yoshida1997 Volume 63 Issue 4 Pages 594-599
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn the north basin of Lake Biwa, harmful dinoflagellate Uroglena americana occurred dominantly, causing bad-smelling tap water in late spring for several years. The relationships between the abundance of U. americana and water quality in the north basin and the meteorological conditions of Lake Biwa were examined. The changes of water quality in the north basin (Station A) of Lake Biwa in early May of 1980-1993 showed that the fluctuation of WT (water temperature), DIP (dissolved inorganic phosphorus), TN: TP (total nitrogen: total phosphorus), DIN:DIP (dissolved inorganic nitrogen: dissolved inorganic phosphorus), and TP:DIP ratios were remarkable. The comparison of each average water quality with regard to the dominant phytoplankton in early May of 1980-1993 showed that U. americana occurred in the waters with water qualities near the mean values, excepting comparatively high WT. The species also occurred in the years with meteorological conditions from mid April to early May close to the mean. These features of water quality and meteorological conditions suggested that the alga was a common species in early May and the control of the dominant occurrences resulted from abnormal water quality and meteorological conditions.View full abstractDownload PDF (426K) -
Tomohiro Ueda, Ryuichi Kusaba, Syun-ichi Kamimura, Emiko Okazaki, Yuta ...1997 Volume 63 Issue 4 Pages 600-607
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSMince of chum salmon mixed with 4% sorbitol, 4% sucrose, and 0.3% polyphosphate salt was stored at -45°C. The frozen mince was thawed and ground with 2.5% NaCl and 150ppm chlorumphenicol. The salted mince was texturized under high pressure of 200-1, 000MPa at 0°C. The texturized gel under pressure (termed the pressure-induced gel) was subsequently kept at 5°C or heated at 30-90°C. The salted mince was also texturized under the pressure of 300 or 500MPa at 20-80°C. The quality of 4 types of these pressure-induced gels was assessed by measuring the breaking strength, breaking strain and the change in myosin heavy chains in the same gels. The results were as follows: (1) The breaking strength of the pressure-induced gel was only slightly reinforced with the following aging period at 5°C, although the breaking strength of the salted mince enhanced with increasing pressure. (2) When the salted mince was texturized with 500MPa at 0°C for 10 min and subsequently heated at 80°C for 30 min, the breaking strength of the gel largely increased and reached a higher value (ca. 650g), but the breaking strain remained at a low level (ca. 9.0mm). (3) The cross-linking of myosin heavy chains hardly occurred in all types of the pressure-induced gels.View full abstractDownload PDF (2729K) -
Shoichi Nambu, Hidekazu Kiuchi, Akemi Ohishi, Toru Kitajima, Ken-ichi ...1997 Volume 63 Issue 4 Pages 608-615
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSMeat blocks from walleye pollack were soaked in solutions containing 0 ?? 1.0M NaCl(N), 0 ?? 1.5M sorbitol(S), or their combinations with varied ratios for 24 hours at 4°C. The increase in N and S of the meat, the denaturation of myofibrillar protein as measured by the loss of Ca-ATPase activity, and the decrease in moisture content of the meat were investigated as a function of soaking time. The results were as follows: (1) During the soaking, N and S permeate into the meat with definite concentration ratio. The permeation ratio of N and S depends roughly on the composite ratio of N and S in the soaking solution. (2) The first-order rate constant for denaturation of myofibrillar Ca-ATPase during the soaking process was largely dependent on the concentrations and the ratio of N and S in meat. (3) There was good negative correlations between the rate of decrease in moisture content of soaked meat and the concentration of NaCl or sorbitol permeated into the same meat.
These findings may be useful to control the quality of meat block during soaking in NaCl and sorbitol mixture.View full abstractDownload PDF (549K) -
Byeung soo Cheun, Hideaki Endo, Tetsuhito Hayashi, Kui shik Kim, Etsuo ...1997 Volume 63 Issue 4 Pages 616-620
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSA simple biosensor for measuring sodium channel blockers, such as tetrodotoxin (TTX) and saxitoxin (STX), and paralytic shellfish poisoning (PSP) consisted of frog bladder membrane, and Na+ electrode. Effects of storage temperature, antiseptic and species of frog on the activity of Na+ channel on the membrane were investigated from the standpoint of practical use.
The results obtained were as follows:
1) The maximum output of the sensor was obtained at 30 to 33°C and pH 4.8 to 6.0.
These values were shown higher in the case of tropical frog than a temperate frog. This was assumed due to the effect of living the environment.
2) Frog bladder was able to keep at 5°C during 7 months, but at -30°C during only 80 days.
3) Antiseptic effect of NaN3 on the frog bladder membrane was recognized in the concentration of 0.003%.View full abstractDownload PDF (347K) -
Minoru Kimura, Masanao Narita, Hiroshi Nomata, Hiromi Kaneko, Hideaki ...1997 Volume 63 Issue 4 Pages 621-626
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSChanges in the frequency of rigor, breaking strength, and ATP related compounds were fol-lowed in the adductor muscle of scallop during storage at 5, 0 and -3°C. The rigor of adductor muscle occurred rapidly as the storage temperature was lowered. The frequency of rigor reached 100% after 6 days at 0 and 5°C, and after 4 days at -3°C, respectively. Therefore, storage of scallop adductor muscle at -3°C was impertinent. In the adductor muscle in rigor, breaking strength and pH were low and K value was high, compared with normal adductor muscle. It was observed that the rigor occurred, when K value increased over 20% and pH decreased below 6.5. From these results K value and pH are suitable indices to evaluate the quality of scallop adductor muscle.View full abstractDownload PDF (1406K) -
Mikio Kikuchi, Meiko Wakabayashi1997 Volume 63 Issue 4 Pages 627-633
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSA biomonitoring test was used to assess whether rivers and streams maintained sufficient water quality to support aquatic life. Daphnia magna were exposed to the water samples collected from 17 sites of 13 rivers and streams in Tokyo and its suburbs and the acute response of D. magna was monitored.
The mobility of the organism was acutely inhibited in the water of six rivers and streams tested. Discharge to these sites was from paddy field, and was a significant proportion of the total flow of the streams and rivers. Gas chromatography-mass spectroscopy of the samples revealed the presence of some pesticides in the water samples. Determination of the toxicity of organophosphate insecticides such as fenitrothion and diazinon to D. magna showed 50% inhibition concentration of mobility at 48-hr exposure (48 h-EC50) of 0.10 to 1.0 μg/l. The concentrations of these insecticides in the water samples correlated well with the toxicity measurements of each sample. These insecticide concentrations accounted for most of the toxicity.
This biomonitoring test using D. magna was highly sensitive and simple. The significance of detecting these insecticides at acutely toxic concentrations to D. magna in some waters of the streams and rivers indicates that they have an adverse effect on some aquatic lives such as crustacean and benthic insects.View full abstractDownload PDF (1283K) -
Hideyuki Kurihara, Tomoko Saiki, Mutsuo Hatano1997 Volume 63 Issue 4 Pages 634-635
Published: July 15, 1997
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSDownload PDF (134K)
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