NIPPON SUISAN GAKKAISHI
Online ISSN : 1349-998X
Print ISSN : 0021-5392
ISSN-L : 0021-5392
Volume 35, Issue 4
Displaying 1-12 of 12 articles from this issue
  • Michiko TANIGUCHI
    1969 Volume 35 Issue 4 Pages 333-335
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    In the study on the disease of conchocelis, it is necessary to use the thalli of conchocelis which has the same cultural age and the similar physiological condition at a desirable time in any season, because the appearance and development of disease is greatly influenced by the physiological condition which varies with the age of conchocelis.
    From the point of view, attempts were made to find the way of getting such conchocelis.
    The results obtained are as follows:
    1. The leafy thalli of Porphyra okamurai can be kept in living state, at least for half a year when they are stored at -12°C after drying in air.
    2. The thalli stored as above mentioned are steeped in sea water for two days, and then cultivate at 22°C under the radiation of continuous light in the enriched sea water, the carpospores are produced and liberated from them. The carpospores germinate into shells and grow as well as the case of the conchocelis obtained naturally.
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  • Development and Growth
    Kazuhisa NISHIMURA, Makoto MIKI, Shigeru ITO, Teruo SHIOYA
    1969 Volume 35 Issue 4 Pages 336-341
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    The writers succeded to get the fertilized eggs “fuku-tokobushi” Sulculus diversicolor diversicolor (REEVE) in August, 1967 and investigated their development and growth for 365 days after fertilization.
    The results obtained are summarized as follows:
    1) Spawning was artificially induced by the stimulation of fluctuations of water temperature, within the range 21.8-28.0°C and the fertilized eggs are taken at the time of lower temperature.
    2) The eggs are spherical in shape and the average diameter is 0.197mm (0.1846-0.2154) including egg membrane, and that of yolk is 0.168mm (0.1539-0.1846) in fertilized condition.
    3) There observed some differences in the development between Sulculus diversicolor diversicolor and S. diversicolor agvatilis as shown in Table 1.
    4) The veliger larvae settle to the bottom from 66 hours to 170 hours after fertilization.
    5) The growth curve of young shell during 330 days is shown in Fig. 3.
    6) It is presumed that Sulculus will reach the legal size (shell length 45mm) at 18 months after fertilization.
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  • Yukimasa KUWATANI, Tamotsu NISHII
    1969 Volume 35 Issue 4 Pages 342-350
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    The present study has been done to make clear the effects of pH of culture water on the growth of the Japanese pearl oyster, Pinctada fucata (GOULD). Thirty five one-year-old oysters were equally divided into 7 groups, which were reared in separate recirculating tanks (Fig. 1) for 40 days. All the groups were given rice powder as food at a rate of 40mg per oyster per day, and 15l out of 40l of culture water in each tank was replaced with fresh sea-water once a day. The pH of water of the experimental tanks was first adjusted to 6 different levels from 7.3 to 8.1 by adding necessary amounts of hydrocloric acid or sodium borate to them and to keep the pH values constant calculated amounts of either chemical was added after every partial change of water, Chemical analysis of culture water and measurement of under-water weight of the animals were made seven times at five or seven-day intervals during the rearing period.
    The results obtained are summarized as follows:
    1) Average pH values of culture water throughout the rearing period were 7.36, 7.48, 7.66, 7.78, 7.89 and 8.07 in the 6 experimental tanks and 8.04 in a control (Fig. 2). As to the alkalinity of culture water of the tanks was in the same order as pH (Fig. 4). No remarkable differences were observed on the other chemical conditions of culture water among the 7 tanks except for the two adjusted to pH 7.36 and 7.48 on the average (Figs. 5-7).
    2) The oyster in pH 8.07 on the average and control tanks showed a rapid growth represented with respective straight lines throughout the rearing period (Fig. 10). Among the other oyster groups such a relation was found that decrease in oyster weight was in a direct proportion to pH. The greater part of the animals reared in pH 7.36 and 7.48 on the average died during the first half of rearing period (Figs. 10 and 11). The relation between the weekly mean value for pH and the daily increase of under-water weight of oysters differed with the stage of rearing (Fig. 14). The weight increases in a certain degree at higher pH, about 7.8 or over, and decreases remarkably at lower pH during the first 19 days. While after 20 days the relation is linear, being represented with the following expression.
    G(mg) 29.589 pH-234.794
    Where G and pH show the weekly mean of daily increase of under-water weight and that of pH after 20 days. The limiting pH for growth is estimated from the expression to be pH 7.935.
    3) From the significance test of the differences among the oyster groups in the dry weight of shell and that of meat at the end of rearing (Fig. 12), and the relationships between the appearance rate of etching and dissolving features on the surface of nacreous layer of the shell and the pH (Fig. 13), it may be concluded that the decrease in under-water weight of the oysters reared in low pH is attributed mainly to the dissolving of the shell rather than the decrease of the meat weight.
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  • On the Source and Route of Infection
    Kenji NAKAJIMA, Syuzo EGUSA
    1969 Volume 35 Issue 4 Pages 351-357
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    Anchovies, Engraulis japonica (HOUTTUYN), in the Bungo Channel and the Sea of Suo and Iyo havour frequently a white worm of 14-48×1.6-4.0mm in size in their body cavities (Fig. 1). This anchovy worm resembles closely a nematode-shaped paratite which is occasionally found in the body cavities of yellowtails in farms in the Bungo Channel area and is suspected to be a immediately previous stage of the plerocercus of a new species of the genus Callotetrarhynchus1). Anchovy is a main feed for the yellowtail culture. These facts suggest that the yellowtail bladder worm may come from the anchovy.
    In order to study this problem three infection experiments were carried out in different seasons in somewhat different ways and yielded the following results.
    (1) The majority of the anchovy worms which were engulfed with feed by yellowtails or forced alone into the stomachs attacked fishes. The infectious rate was 53.8 to 71.5%.
    (2) The anchovy worms which had received into the stomach penetrated the stomach wall within a short period of time (Fig. 2 and 3) and moved to various parts of the body cavity. Inactive worms were thrown into the intestine and excreted sooner and later.
    (3) The worm settled at any parts of the body cavity were encysted with a tissue membrane from host and developed gradually into plerocercus.
    (4) The scolex of the plerocercus was exactly the same as that of Callotetrarhynchus sp. reported in the previous paper1) both in the arrangement and shape of the hooks on the tentacles and in the size and proportions of the bothridium, sheath and musclar bulb.
    (5) The activity and develepment of the anchovy worm in the body cavity of yellowtail were thought to be definitely affected by water temperature. The penetration of the worm through the stomach wall required over 4 hours in winter but less than 1 hour in summer, and the formation of the scolex was noticed 25 to 30 days after infection in summer, while not until 50th day in winter.
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  • Hisatsugu WAKABAYASHI, Syuzo EGUSA
    1969 Volume 35 Issue 4 Pages 358-361
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
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  • Investigation of the microclimate in the culture net of Porphyra tenera
    Osamu IMADA, Shin ANDO, Shigeru MAEKI
    1969 Volume 35 Issue 4 Pages 362-378
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    From October 7 to November 28 in 1966, we have examined the cultural conditions for the growth of Porphyra tenera in the Ariake-Sea (Fukuoka Pref.). Then, we have investigated the relationships among growth, injury of fronds and the microclimate of the culture net. The harvest of fronds have been very poor this year, because the injury “Shirogusare” has happend.
    Our measurements items are as follows:
    1) area of fronds, 2) growth rate of fronds, 3) injury percentage of fronds by colored cells, 4) temperatures of atmosphere, sea water, and culture net, 5) density, pH, desolved oxygen and nutrients (NH4-N, NO3-N, PO4-P) of the sea water, 6) speed of sea water by the tide, 7) the weather, 8) speed and course of the wind, 9) light intensity in the sea water by sun shining.
    These data have been obtained continuously, or at least one time per day. We have also obtained some original data about culture conditions, growth, and injury of Porphyra tenera. Some discussions about these relationships are made.
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  • Seasonal changes of Blood Elements, Electrophoretic Pattern of Serum Proteins and their Percentage Fractions
    Hideo YAMASHITA
    1969 Volume 35 Issue 4 Pages 379-385
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    From the results of preliminary experiments made during the preceding five years, using 177 specimens of rockfish, Sebastiscus marmoratus, it became evident that a few individual fish are enough for the analysis of the seasonal change of the blood elements of this species (Table 1, Fig. 1). Three rockfish were, therefore, kept in a concrete tank (0.7m3) of circulating sea water during the period of one year. The blood was drawn six times from each individual to compare the seasonal change of the blood elements (Table 2).
    Sampling of the blood, measurements of the specific gravity, serum protein and haematocrit, and electrophoresis were done following the same techniques used in the previous studies.
    In both male and female, the specific gravity of the blood, the amount of serum protein and haematocrit value were most high during October and November, the period when spermatozoa are discharged in the male. The lowest values were found in February, when the female of this species is usually liberating viviparous larvae (Fig. 2).
    Five fractions were observed in the electrophoretic pattern of serum protein. These components were separated clearly throughout the year in the female, while sometimes they were not separated distinctly in the male (Fig. 3).
    The percentage of serum protein fractions varied with the season. Component I showed the minimum and Component In the maximum during the period discharging spermatozoa, in both the male and the female (Fig. 4). It is of interest to note that the change in the amount of blood elements as well as its seasonal percentage occurrence seemed to coincide fairly well with some physiological characteristics, i.e. the development of sexual glands, of the rockfish.
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  • Teiji KARIYA, Masao TAKAHASHI
    1969 Volume 35 Issue 4 Pages 386-390
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    The food intake and its relation to the stomach contents at the time of feeding in the mackerel, Scomber japonicus were studied by using the fishes of about 31 ?? 26 gr body weight which had been well trained to eat pieces of anchovy meat to the full in net cages set up in the sea.
    Starvation in the strict sence of the word was thought to start in this species of fish after 3.5 days of fasting, when the total stomach weight reached the minimum (Fig. 2). The food intake in weight in starved fish was about 23% of the body weight at the highest and 16% in average when they were satiated with anchovy meat at about 20°C. The stomach contents decreased rapidly with time, reaching about 20% of the initial weight after 5 hours and 1.8% after 10 hours (Fig. 3). The digesive process was completed in 21 to 24 hours (Fig. 4). pH of stomach contents was about 6.7 before feeding and was reduced rapidly after feeding, reaching 4.1 after 7.5 hours.
    Fishes took food actively even though part of the foods which they had previously taken remained in their stomachs. The amount of the intake was inversely proportional to the amount of the residues (Table 1, and Fig. 5). This suggests that digestion curve may be determined from feeding curve in the mackerel.
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  • Decomposition Products Found in Several Fishes
    Harumi TOZAWA, Keishi AMANO
    1969 Volume 35 Issue 4 Pages 391-396
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    The flesh of fish rich in the content of trimethylamine oxide (TMAO), such as cod, Alaska pollack, shark and cuttle fish were subjected to gamma-irradiation at dosages from 0.6 to 5.6 Mrad, to observe how TMAO, a specific constituent in marine fishes, would break down and if it would result in causing undesirable effects on the quality of the irradiated fishes.
    Trimethylamine (TMA), dimethylamine (DMA), and formaldehyde (FA) were identified after irradiation in all the samples of the fish flesh and in TMAO solution as well. An increase in the amount of ammonia was detected in the same fish samples after irradiation, but very little amount in the irradiated TMAO solution (Table 3).
    The difference in the quantity of TMA produced by the irradiation was not so apparent among the fishes examined. But, the difference in the quantity of DMA was apparent, i.e., the amount of DMA formed in the flesh of gadoid fish was larger than that in shark or cuttle fish (Fig. 1, Table 2). And, a remarkable difference in DMA level was noted between two individuals of Alaska pollack irradiated at the same dosage. A significant fact was that the amount of DMA in one of the irradiated flesh of Alaska pollack was extremely larger than that produced from pure TMAO solution under the identical condition of irradiation.
    The precursor of FA formed by irradiation of fish flesh would not be limited to TMAO, however, a comparatively large amount of “free” FA recovered from the irradiated flesh of gadoid fishes was presumed to be derived from TMAO in the tissues (Table 4).
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  • Acceleration of DMA Formation by Addition of Gadoid Fish Viscera
    Harumi TOZAWA, Keishi AMANO
    1969 Volume 35 Issue 4 Pages 397-404
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    In the previous paper, it was reported that the amount of DMA produced during gammairradiation was higher in the flesh of gadoid fishes than that in shark or cuttle fish, and, in some case, it was even higher than the amount of DMA found in pure TMAO solution irradiated under the identical condition. A certain agency was supposed to be involved in this extraordinarily large quantity of DMA formation.
    The tissues of gadoid fishes, especially the viscera, have been known to bear an enzyme system able to convert TMAO into DMA and formaldehyde. In this context, the authors presumed that the enzyme might be concerned with DMA formation in gadoid fishes as a promoting factor during the irradiation. The presumption mentioned above was likely supported by the following findings of experiments mainly on cod flesh-cod viscera mixture (20:1) as samples subjected to irradiation at 3.0 Mrad.
    1. The formation of DMA during the irradiation in cod or Alaska pollack flesh revealed a marked acceleration by the addition of the viscera of these fishes, especially by cod pyloric coeca (Figs. 1 and 2). A similar acceleration effect was also observed in the samples which consisted of horse mackerel flesh or TMAO solution and cod pyloric coeca (Figs. 6, 7 and 8).
    2. The “acceleration effect” never occurred when the pyloric coeca was heat-processed before adding it to the flesh (Fig. 4).
    3. The “acceleration effect” was very weak or scarcely observed in a test when cod flesh was mixed with each pyloric coeca of horse mackerel, skipjack and gurnard or hepatopancreas of carp; these tissues were assumed to possess very low level or none of the enzyme activity concerned with DMA formation from TMAO (Fig. 5).
    No “acceleration effect” was observed when the irradiation on flesh or pyloric coeca was conducted separately, or either of these materials was irradiated alone, prior to the preparation of the mixture (Tables 2 and 3). In other words, the acceleration occurred during the irradiation only and not after the irradiation. This may suggest that the acceleration should be dependent on the active role of free radicals generated during the course of irradiation.
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  • Takeshi TAGUCHI, Kosaku SUZUKI, Isami OSAKABE
    1969 Volume 35 Issue 4 Pages 405-409
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
    (1) The content of magnesium and calcium in the various tissues of fish and squid were determined by the atomic absorption spectrophotometry. The results showed that the contents were 4-36mg % in calcium and 10-41mg % in magnesium. The highest content of magnesium was found in the dorsal muscle in all the species of fish examined.
    (2) On the liberation of magnesium and calcium from the muscle proteins, the chelating agency was postulated to become weaker immediately after the storage, as judged by the increment of the amount liberated.
    (3) Centrifugal fractionation of the carp muscle homogenate revealed that the cellular magnesium was present in all the particles fractionated.
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  • Shiro KONAGAYA, Kazuoki YAMABE, Keishi AMANO
    1969 Volume 35 Issue 4 Pages 410-416
    Published: April 25, 1969
    Released on J-STAGE: February 29, 2008
    JOURNAL FREE ACCESS
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