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Volume 39, Issue 4
Displaying 1-19 of 19 articles from this issue
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Chia-Ren CHIU, Kiyoshi SAKAI, Fumio TAKASHIMA1991 Volume 39 Issue 4 Pages 343-351
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSOogenesis, spermatogenesis and spawning season were histologically investigated, and moreover ovulation was accelerated with LHRH-a and triploidy was induced by cold shock in largemouth bass, Micropterus salmoides collected at Inbanuma. Oogenesis of this species is classified to asynchronous oocyte development type: oocytes at almost all developmental stages were present during the spawning season. The spawning season was April to June, estimated by the presence of empty follicle cells. On the other hand, spermatogenesis actively preceeded twice a year. April to June and Octorber to November.
Injection of 15-80μg/kg in body weight of LHRH-a induced the acceleration of ovulation: ovulation was checked in 31.5-55 hours after LHRH-a cholesterol pellete was implanted at 17-25°C.
Triploidy was induced by putting eggs in 3-7 minutes after insemination into cold water (0°C) for 20-30 minutes.View full abstractDownload PDF (7179K) -
Katsutoshi KIDO, Yasunori WATANABE, Yukio NAKAMURA, Takeshi OKAMURA1991 Volume 39 Issue 4 Pages 353-362
Published: December 15, 1991
Released on J-STAGE: December 10, 2010
JOURNAL FREE ACCESSStudies were conducted on critical levels of ammonia in sea water for eggs and larvae of the red sea bream, Pagrus major (TEMMINCK et SCHLEGEL) . Values of the median hatching concentration (HC50) for eggs and the median lethal concentration (LC50) for larvae were determined using bioassay techniques by the normal survival rate as criteria. Under experimental conditions of water temperature 20°C, pH 8.03-9.35 and salinity 34.26-34.46‰, HC50 for eggs were 6.6-7.0 ppm-NH4-N. Corresponding un-ionized ammonia values obtained by calculation ranged from 0.79 to 0.88 ppm-NH3-N. Under conditions of 21°C, pH 8.11-8.97 and salinity 33.81-34.39‰, 21-168hr-LC50 values for three sizes of larvae, 7.5, 15.9 and 52.7mg in mean body weight, were evaluated. The 96hr-LC50 values for 15.9 and 52.7mg size were 3.0 and 4.9 ppm-NH4-N (equivalent to 0.26 and 0.58 ppm-NH3-N), respectively. LC50 values for the smallest size decreased as exposure time elongated, showing 5.0, 2.9, 2.6 ppm-NH4-N at 21, 44, 68hrs, respectively, while for the larger two sizes, the values were sustained almost constant during exposure of 25-96hrs for 15.9mg group or of 26-168hrs for 52.7mg group.View full abstractDownload PDF (1151K) -
Haruo SUGITA, Ken-ichi MASE, Masaru IWATA, Shuji KATO, Chie SUGIURA, R ...1991 Volume 39 Issue 4 Pages 363-369
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe vitamin B12-producing ability of the gut microflora in four marine gastropods, including giant abalone Nordotis gigantea, Japanese abalone Sulculus diversicolor aquatilis, turban shell Batillus cornutus and “Bateria” shell Omphalius pfeifferi, was examined. Vibrio groups 4, 5, 6, 7, 8 and 9, along with Pseudomonas, were widely distributed in the gut of the marine gastropods examined. Any obligate anaerobes were not isolated from both the seawater samples and gut specimens. A total of 270 strains of bacteria (including yeasts) isolated from the seawater samples and gut specimens were examined for the vitamin B12-producing ability by measuring the increased amount of vitamin B12 in a culture medium. Mean producing ability of the strains from marine shells ranged from 1.2 to 2.5 ng/ml/OD630, and is comparable with that from seawater (1.7 ng/ml/OD630) . Generally, the bacteria isolated from both the seawater samples and gut specimens performed poorly in producing vitamin B12, except for four strains of Vibrio group 9 (12% of cultures of each bacterial component), three of Vibrio group 8 (9%) and Moraxella (30%), two of Staphylococcus (14%), and one of Vibrio group 7 (5%), coryneforms (20%) and Bacillus (17%), which produced the vitamin at levels greater than 5 ng/ml/OD630. These results suggest that the bacterial productivity of vitamin B12 in the gut of marine gastropods is lower than that of freshwater fishes such as tilapia Oreochromis niloticus and carp Cyprinus carpio.View full abstractDownload PDF (854K) -
Masami HAMAGUCHI, Riichi KUSUDA1991 Volume 39 Issue 4 Pages 371-374
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSTo control pseudotuberculosis in yellowtail, Seriola quingeradiata, the effect of hen egg lysozyme in yellowtail administrated by oral and immersion methods was investigated. After administration by oral route of hen egg lysozyme, the percent survival of the fish to experimental challenge was not increased significantly. The quantity of lysozyme contained in serum and skin mucus extract was not increased. After administration by immersion, the percent survival of the fish was increased significantly in the group treated at the 0.1 mg/ml hen egg lysozyme, and the lysozyme activity in skin mucus extract was increased.View full abstractDownload PDF (521K) -
Osamu ISHIDA, Yukimitu SAKAMOTO, Hiroyoshi TAKAHASI1991 Volume 39 Issue 4 Pages 375-379
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSWhen ultraviolet irradiation stimulus was given to induce spawning in abalon Haliotis discus, , synchronism were observed in the separate spawning tanks.
The percentage of animals spawned within ten minutes of the mode time was in the range 35.7 to 55.6 percent except for the experiment 9. The time to spawning from the start of the UV treatment was fluctuated often by water temperature of spawning tank. The time was short in higher temperature long in lower temperature.View full abstractDownload PDF (452K) -
Tougo MIYAZAKI1991 Volume 39 Issue 4 Pages 381-385
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe smoltification rate of female triploid masu salmon, Oncorhynchus mason, which were 17 month old, was examined. And sodium concentrations in serum of the fish after transfer from freshwater to 2/3 sea water were measured for 3 days.
Though the smoltification rate in the diploid group which is yielded with normal mating (control group) was 53.8%, it was 100% for the triploid group. Average sodium concentration in serum of parrs in the control group was higher than 5, 000 ppm after transfer from freshwater to sea water. However, sodium concentration of triploid fish ranged from 3, 990 ppm to 4, 100 ppm, and significantly lower than the measurement of parrs in the control group. No difference in serum sodium concentration between smolts in the triploid group and smolts in the control group was observed.
These results suggest that almost all female triploid masu salmon are transformed to smolt, and that they are able to adapt to sea water environment as well as diploid smolts.View full abstractDownload PDF (496K) -
Kazuhiro KUROSAWA1991 Volume 39 Issue 4 Pages 387-391
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSIn the oyster farming areas in Luzon, Philippines, C. iredalei is the dominant and commercially important species. However, some other species in the genus Saccostrtea also occur in the same areas and are usually regarded as the foulings. Among the population of the genus Saccostrea, S. tuberculata is the most abundant species, but its larval shape has not been reported. In this study, features of larval shell morphology of these two species were compared so that they could be discriminated each other from the plankton sample upon the larval distribution / abundance survey. The observation on artificially reared larvae showed that the larval shell of C. iredalei could be differenciated from that of S. tuberculata on the basis of following charecteristics: 1) C. iredalei had a larger umbo which extended postero-dorsally (opisthogyral umbo), while S. tuberculata had a smaller umbo extending straight dorsally (orthogyral umbo) . 2) valve margin of C. iredalei was projected antero-ventrally, forming asymmetrical shape, and its right valve was oval. S. tuberculata had rather symmetrical shape, and its right valve was nearly round. 3) Shell length of C. iredalei equaled height when it measured 80-90 μm, then height exceeded length in later development stages. The relationship between shell height (H) and shell length (L) was shown by the equation, H=1.1246L-6.1109 (r=0.993, n=145) . On the other hand, these dimensions of S. tuberculata became equal at 90 μm and above, but the equality was maintained even in larger-sized larvae. The length: height relationship was shown by the equation, H=1.0023L-9.8844 (r=0.994, n=124) .View full abstractDownload PDF (549K) -
Kazuhiro KUROSAWA, Susan CAOILE, Annabelle CARIAGA1991 Volume 39 Issue 4 Pages 393-398
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSEffect of ozone on depuration of tropical and temperate oysters was studied. In the preliminary experiment conducted in Japan, 25kg of oysters (C. gigas) were successfully depurated within 24 hours in a laboratory-scale recirculating system by intermittent ozone injection at the rate of 0.015 and 0.021mg per hour per 1 l seawater in the entire system. At lower dose (0.008mg/h/l) or higher doses (0.031-0.309mg/h/l), the oysters were not depurated to acceptable level (<230 fecal coliform MPN) .
Under the tropical conditions, 66-125kg of oysters (C. iredalei) were effectively depurated in a pilot-scale recirculating system by ozonation in wide range of dose rate (0.058-0.392mg/h/l) . Dissolved ozone concentration in the seawater during these traials was under the minimum detectable level (0.02mg/l) of an ozone detector. Nitrite and dissolved oxygen concentrations were mostly maintained at acceptable levels to the oysters by the effect of ozonation, but accumulation of ammonium was not appreciably controled.View full abstractDownload PDF (696K) -
Ken-ichi YAMAMOTO1991 Volume 39 Issue 4 Pages 399-402
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSIn the jack mackerel, oxygen consumption and minute ventilation volume under the resting condition were kept the similar level to that under normoxic condition in over 21.9±1.6% in oxygen saturation and in over 43.6±1.1%, respectively. The largest level of oxygen consumption under the recovery condition from the severe exercise of 15 min was kept the similar level to that under normoxic condition in over 75.3±2.2%.
From the above, it is considered that the fish is effected the change on the respiratory movement by hypoxia in below 75% in oxygen saturation, but the survival of one must be possible in over 44% under severe physical disturbance.View full abstractDownload PDF (455K) -
Xiao-tao LIN, Naonori ISHIWATA1991 Volume 39 Issue 4 Pages 403-406
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe zoeal larvae of Macrobrachium rosenbergii were fed with Artemia nauplii at densities of 0.5, 1, 3, 5 and 10 individuals per ml in aquaria with circulating water at 28°C and 10.5‰ S, and the effect of food density on the survival and metamorphosis was examined. The survival rate and metamorphosis ratio of zoeae fed at densities of 5 and 10 individuals per ml were markedly higher than those fed at densities of 0.5, 1 and 3 individuals per ml. The number of days required to metamorphose prolonged as food density was lowered. The results of the study indicate that it is desirable for the optimal development of the zoeae to be fed with Artemia nauplii at a density of 5 individuals per ml.View full abstractDownload PDF (389K) -
Xiao-tao LIN, Naonori ISHIWATA1991 Volume 39 Issue 4 Pages 407-411
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe zoeal larvae of Macrobrachium rosenbergii were fed with A) Artemia nauplii, B) Artemia nauplii supplemented after 10 days with short-necked clam meat and C) supplemented after 15 days, D) Artemia nauplii were replaced after 10 days with short-necked clam meat and E) replaced after 15 days in aquaria with circulating water at 28°C and 10.5‰ S, and the effect of food type on the survival and metamorphosis was examined. The survival rate and metamorphosis ratio of the zoeae fed A, B and C were markedly higher than those fed D and E. The number of days required to metamorphose showed no difference in all the groups. The results of the study indicate that for the optimal development of the zoeae they require to be fed with Artemia nauplii or Artemia nauplii supplemented with short-necked clam meat after 10-15 days.View full abstractDownload PDF (454K) -
Fumio KATO1991 Volume 39 Issue 4 Pages 413-421
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe Biwa salmon, Oncorhynchus sp. transforms from parr to smolt in July in Lake Biwa when it comes about 80 mm in standard length. The body color of the smolt is silvery and the parr marks are not present anymore. The fish have red spots on the lateral sides and do not show intense blackening at the tip of dorsal fin. Changes of body color and body shape associated with parrsmolt transformation are less obvious than those of the Amago or Masu salmon. After descending into the lake, they inhabit the offshore waters of the lake deeper than 10-20m, feeding mainly on Anisogammarus annandalei. They grow to a standard length of about 150 mm in March at one year of age. Near the scale's focus of the smolt, ridges are formed in close order. This zone is called“fry zone”in the Biwa salmon studied in the present paper and also in the Pink salmon, O. gorbsca. After descending into the lake, the fry zone of the Biwa salmon is formed in June at about 70 mm in standard length, and the number of ridges is 6-11 (mean 7.1) . The rate of apperance of the fry zone is very high. It is thought that the fry zone is formed as a result of physical changes in the environment.View full abstractDownload PDF (1012K) -
Tadahide NORO, Takao NEMOTO1991 Volume 39 Issue 4 Pages 423-427
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSDevelopment of the gametophyte and sporophyte of edible green alga, Monostroma, cultured by fishermen in Azuma-cho, Kagoshima, Japan, was observed to clarify the taxonomy of this species.
Thallus (gametophyte) of the Monostroma released biflagellate male and female gametes in April. The male gamete was not clearly marked off from the female in size (4.7±0.8μm long, 3.0±0.4μm wide) . These gametes conjugated to form zygotes (sporophyte) which survive the hot summer season. The zygotes were grown 60-70 μm by August. In September, quadriflagellate zoospores were released from these zygotes. After settlement on substrate, these zoospores grew to be filaments at first stage then uni-membranaous thalli but never passed through the tubular shape even in the early stage of development. This morphological development, especially in the early stage of gametophyte, was the same as observed in M. latissimum that naturally distributed in the central part of Japan.View full abstractDownload PDF (4635K) -
Tadahide NORO, Takao NEMOTO1991 Volume 39 Issue 4 Pages 429-434
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSSeasonal growth of an edible green alga, Monostroma latissimum cultured on a net was studied in Kagoshima, Japan.
Zygotes of M. latissimum, which had survived hot summer on gravels in shallow sea bottom, started releasing zoospores when the water temperature decreased less than 25°C in September. The maximum peak of releasing zoospores occured in the middle of October. These zoospores attached and grew actively in the tidal level between 120 to 180 cm. However, the culture net was recommended to be set between 120 to 140 cm tidal level to prevent the growth of other algae, e. g. Enteromorpha spp. Thallus (gametophyte) of M. latissimum on the net started growing in October and reached to be the harvestable size (40-50cm2/frond) by March. Then withering thallus was drifted off from the net in April.View full abstractDownload PDF (572K) -
Hisaki NAKAGAWA, Shinya ISHIO1991 Volume 39 Issue 4 Pages 435-440
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSIn order to compare the sensitivity of the medaka Oryzias latipes at specific stages in its life history the 48-hr LC50s for Cd2+, Cu2+, Ag+ and Cr2O72- were measured at three growing stages of egg, newly hatched larva and adult. The eggs at nine embryonic stages were also tested to determine the changes in sensitivity during the development. The embryos shortly before and after hatching were significantly more sensitive to all four heavy metal ions than any other embryonic stages. The susceptibility of eggs to Cr2O72- and Ag+ was particularly not uniform throughout the embryonic development. Results of the 48-hr LC50s verified that the eggs were more resistant than the newly hatched larvae and adults though comparative sensitivity of the eggs and adults to Cd2+ could not be confirmed. The newly hatched larvae were more sensitive to Cd2+ and Cu2+, but were slightly more sensitive to Cr2O72- and Ag+ than the adults.View full abstractDownload PDF (692K) -
Shigenobu OKUMURA, Keiji HIROSE1991 Volume 39 Issue 4 Pages 441-445
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSFor artificial fertilization in red tilefish, cryopreserved spermatozoa were prepared from the dead fish which were caught in Wakasa bay. Minced testes were homogenized, diluted with the extender solution, packed in polyethylene tubes and preserved in liquid nitrogen for 740 days. The motility of spermatozoa was reduced to 60-40% from over 80% after the preservation period. Six female fish were injected with human chorionic gonadotropin (HCG) . Four females were induced to ovulate following the treatment. Cryopreserved spermatozoa were used for artificial fertilization. Fertilized eggs were obtained from three HCG-treated females. The number and ratio of fertilized eggs were 7, 950 and 31%.View full abstractDownload PDF (2774K) -
MUSTAHAL, Hachiro HIRATA1991 Volume 39 Issue 4 Pages 447-453
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSIn order to know environmental adaptation of the rotifer, salinity adaptability of five strains of the rotifer originated from different areas were investigated. The five strains used in this study were: what is called as L-type strain, Brachionus plicatilis typicus from Yashima (YL) and Israel (IL), and S-type strain Brachionus plicatilis rotundiformis from Yashima (YS), Malaysia (MS), and Java, Indonesia (JS) .
The rotifers which have previously been cultured at 20 ‰ salinity were isolated individually into microplate chambers in which contained the medium salinities of 5, 15, 25, 35, and 45 ‰. The rotifers were acclimated in these salinities for 0, 15, 35, 55, 75 days, respectively. The alga, Nannochloropsis sp. was used as food at density of 2-3 × 106 cells/ml. The medium was renewed every day until all individuals died. The parameters observed in this study were emphasized on the life span of the rotifer, their offspring number and growth rate, which were calculated by the method of Birch. The slopes of regression line of each parameter and its acclimation periods were used to estimate the initial and final values, and the increment rate of their adaptability to the various salinities.
The results summerized as follows: the average life span in all salinities were shown by YL strain at 10.3 days, the longest among the strain tested in this experiment, followed by MS strain at 9.0 days, YS and IL strains at 8.5 days, JS strain at 7.8 days, respectively. For average of total offspring number in all salinities, MS strain shows the highest at 14.9 ind/gen., followed by JS strain at 12.3 ind/gen., YS strain at 12 ind/gen, and YL strain at 11.0 ind/gen. For the growth rate in all salinities, JS strain showed the average of 0.6, followed by MS strain at 0.59, IL strain at 0.5, YL and YS at 0.47, respectively. As the conclusion, it is assumed that the YL strain is most likely to show the highest adaptability in all salinities compared to the other strains.View full abstractDownload PDF (712K) -
Yasuhiro NISHIUCHI1991 Volume 39 Issue 4 Pages 455-458
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSDecreasing effect of charcoal, almina and soil on fish-toxicity of pesticides was experimentally examined, using himedaka, Oryztias latipes.
Results were as follows:
1. Powder charcoal has higher decreasing effect than granule charcoal.
2. The effect of charcoal was found to appear immediately after addition to water.
3. Neither almina nor soil was found to have the fish-toxicity decreasing effect.View full abstractDownload PDF (304K) -
1991 Volume 39 Issue 4 Pages 459-467
Published: December 15, 1991
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSDownload PDF (2375K)
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