Fisheries science
Print ISSN : 0919-9268
Volume 65, Issue 3
Displaying 1-35 of 35 articles from this issue
  • Noritaka Hirazawa, Takashi Hara, Toru Mitsuboshi, Jiro Okazaki, Kazuhi ...
    1999 Volume 65 Issue 3 Pages 333-338
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The suitable egg developmental stage and effective iodophor (Povidon-iodide) concentration for disinfection of spotted halibut Verasper variegatus and red sea bream Pagrus major were investigated. In spotted halibut, the suitable egg stage was the beginning of heartbeat, a day before hatching. The eggs were disinfected successfully by treatment with seawater containing iodophor at 75 ppm activeiodide for 15 minutes. The hatching rate was decreased at higher concentrations. In red sea bream, the morula stage was most suitable for the treatment. The most successful concentration for disinfection was 100-200 ppm active iodide applied for five minutes. Furthermore, in spotted halibut, iodophortreatment did not have any harmful influence on survival, growth and occurrence of deformity. In thecase of red sea bream, when eggs were obtained from the early spawning period, iodophor treatmentseemed to reduce the survival rate of the larvae at an early stage, presumably due to egg quality. Growthand occurrence of deformity were not affected. The results suggest that the conditions for disinfection shown above are suitable for seed production. Moreover, the optimum conditions for iodophor disinfection of eggs differed between these two species. It is suggested that conditions for disinfection of eggs should be determined senaratelv for each fish species.
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  • Woo-Seok Gwak, Tadahisa Seikai, Masaru Tanaka
    1999 Volume 65 Issue 3 Pages 339-346
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Japanese flounder Paralichthys olivaceus larvae and early juveniles were reared for 43 days after hatching in order to observe the effects of starvation during development and metamorphosis. Morphological and histological measurements were made to assess the nutritional status during growth and starvation from prematamorphic through postmetamorphic phases. Two groups of fish were compared; one with sufficient food supply and one under continuous starvation until death. The activity changes of fish during starvation were also observed.
    Among morphometric analyses, both ratios of body height at anus/head height and pre-/postanal lengths appeared to be sensitive to starvation during which substantial reduction was observed within a day of food deprivation. Starved fish gradually decreased swimming speed as starvation proceeded and finally stayed motionlessly on the tank bottom. Histological variables as intestinal and rectal epithelial heights and gall bladder volume changed significantly with onset of starvation. The gut epithelial heights of starving fish decreased with advances in starvation, although they fluctuated during the mid-metamorphic phase. In contrast, gall bladder volume increased remarkably soon after starvation. Ontogenetic changes in both gut epithelial height and gall bladder volume were evident, those associated with settlement and/or completion of metamorphosis. These findings suggest that a combination of morphologically and histologically sensitive characteristics could be utilized as a reliable measures to evaluate the nutritional status related to starvation in wild Jaoanese flounder larvae.
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  • Yuki Tokuda, Haruhiko Toyohara, Tatsuo Kina, Morihiko Sakaguchi
    1999 Volume 65 Issue 3 Pages 347-352
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Monoclonal antibodies (rnAb) FB17 was produced against Japanese flounder Paralichthys olivaceus serum immunoglobulin. Western blotting analysis showed that FB17 rnAb recognized the H chain of Japanese flounder IgM. Furthermore, FB17 mAb was reacted with surface immunoglobulin (slg) expressed on lymphocytes. FB17 mAb was applied to characterize lymphocytes in peripheral blood and thymocytes of Japanese flounder according to the expression of slg. Flow cytometric analysis showed that about 40% of the lymphocyte-enriched fraction were slg-positive and that almost all thymocytes were slg-negative.
    Peripheral blood leucocytes (PBL) separated according to their adherence to a nylon fiber column were examined as to the expression of slg. As a result, 91% of the adherent cell population expressed slg, while only 3.2% of the non-adherent population did. The slg+ cells found in the non-adherent population were stained more dimly than those in the adherent population. These results suggest that Japanese flounder slg+ cell consists of at least two distinct subpopulations; one which expresses more slg molecules and adheres to nylon fiber and the other which expresses less slg molecules and does not adhere to nylon fiber. These characteristics of Japanese flounder slg+ cells were similar to those of murine B cells.
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  • Estu Nugroho, Nobuhiko Taniguchi
    1999 Volume 65 Issue 3 Pages 353-357
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Six primer sets were designed from the greater amberjack, Seriola dumerili, and tested to greater amberjack and three other species of genus Seriola. The primer sets tested have only scorable product in samples from the same genus and may not be available to amplify DNA from the other genera. Four of those loci were polymorphic for greater amberjack, and three loci were polymorphic for other species of genus Seriola, with number of alleles ranging from 2 to 16, and observed heterozygosities between 0.350 to 0.800. Species S. lalandi has the highest variability, while the lowest belongs to species S. rivoliana. Genetic distance, calculated over those loci for all species samples, shows a clear clarification of species according to the taxonomic arrangement. These loci show potential as genetic markers for assessment of genetic variability and population genetic study of species of genus Seriola.
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  • Yuji Tomaru, Zen'ichiro Kawabata, Ken'ichi Nakagawa, Shin-ichi Nakano
    1999 Volume 65 Issue 3 Pages 358-361
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    We conducted an experiment to see vertical distribution of the pearl oyster Pinctada fucata martensii spat, in Uchiumi Bay, east side of Bungo Channel, Japan. Since there is an intrusion of Kuroshio Front (Kyucho), the water quality of the bay is strongly affected by the Kyucho. Collectors of spat were placed from the 1 to 10m at 1m intervals, and the 15, 20 and 30m depths from June 18 to August 22, 1997. The spats were abundantly distributed from the 1 to 10m depth, and most abundant at 6m depth. Few spats were found from the 15 to 30m depth. Although some mechanisms such as water temperature and salinity have been reported in the literature as important environmental factors which determine vertical distribution of bivalve spat in experimental systems, we could not find significant relationships between vertical abundance of P. fucata martensii spat and vertical profiles of some environmental variables. The relationships between the vertical distribution of the spat and the environmental factors in natural environments are thus complicated. The result in the present study is an important information on the vertical distribution pattern of P. fucata martensii spat in natural environmets.
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  • Yoshihisa Fujio, Masamichi Nakajima, Anna Alexandrovna Barinova
    1999 Volume 65 Issue 3 Pages 362-366
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The change of gene frequencies at the AAT-1* and PGM-1* loci was examined in the two guppy strains, S and S3, which had been maintained as a closed colony for a period of 16 years. These strains had been separated from an original strain in 1981. In the S strain, the *α allele frequency at AAT-1* locus changed from 0.282 in 1981 to 0.602 in 1997, and the *α allele at the PGM-1* locus changed from 0.772 to 0.430. On the other hand, in the S3 strain, the *α allele frequency at the AAT-1* locus changed to 0.395 in 1997, and the *α allele at the PGM-1* locus changed to 0.528.
    The effective population size (Ne) during the maintenance period of the guppy strain was estimated based on the magnitude of the random drift in the gene frequency. The estimated Ne was initially 623 in the S strain and 413 in the S3 strain. The decrease of Ne over a period of 16 years was demonstrated to be 18 in the S strain and 24 in the S3 strain, and these phenomenon may be led by the sampling of mature fish.
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  • Mineo Yamaguchi, Shigeru Itakura
    1999 Volume 65 Issue 3 Pages 367-373
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The dinoflagellate, Gymnodinium mikimotoi, causes severe red tides which have been associated with mass mortality of marine fish and invertebrates in western Japan. To establish the background biological information to elucidate the mechanism of red tide outbreaks, nutrition and growth kinetics in nitrogen (N)- or phosphorus (P)-limited semi-continuous cultures were examined using an axenic strain. G. mikimotoi is able to grow using organic and inorganic N compounds as sole N sources. Nitrate, nitrite, and ammonium were found to be good nitrogen sources. Urea and uric acid were not so well utilized and none of the amino acids, except for glutamine and tryptophan, were utilized. G.mikimotoi was capable of using a wide variety of inorganic and organic phosphorus compounds of different molecular structure successfully as a sole P source. Under N-limited steady state conditions, dilution rate (=growth rate), as a function of cell nitrogen quota, followed the Droop equation. Similarly, dilution rate, as a function of cell P quota, followed the Droop equation under P-limited steady state culture. Kinetic parameters Dm and Kq obtained for N- and P-limited cultures were 0.54 day-1 and 3.13 pmol-cell-1, and 0.67 day-1 and 0.25 pmol-cell-1, respectively. The nutrient availability and kinetic parameters of G. mikimotoi were compared to other red tide organisms and the ecological implications of these characteristics were discussed.
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  • Ricardo Perez-Enriquez, Nobuhiko Taniguchi
    1999 Volume 65 Issue 3 Pages 374-379
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The feasibility of microsatellite DNA as genetic tags for the evaluation of stock enhancement programs was assessed. Five microsatellite DNA loci were used to obtain the microsatellite fingerprint of two samples of red sea bream Pagrus major, taken from the wild. The fingerprint of the broodstock used for the stock enhancement program carried out by the Kochi Prefecture Aquaculture Center was also obtained. The low probabilities of identity observed (5.7 × 10-9 and 3.3 × 10-10 for the two analyzed samples) indicated the potential of microsatellites for the identification of individual fish. A parentage test performed between the wild fish and the broodstock indicated that there were no released fish in the samples taken from the wild. Possible reasons for these findings are discussed in terms of a low abundance of released fish in the sampling area due to a low mixing ratio between the released fish and the wild population, combined with a probable high mortality rate of the fish after the release. The use of microsatellites as genetic tags is recommended for the evaluation of release programs of red sea bream.
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  • Sungchul C. Bai, Xiaojie Wang, Eunsun Cho
    1999 Volume 65 Issue 3 Pages 380-383
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Six isocaloric diets containing 30, 40, 45, 50, 55 and 60% crude protein (CP) were fed to juvenile yellow puffer Takifugu obscyrus to determine their optimum dietary level of protein. After a 12-week feeding trial, weight gain of fish fed 50% CP diet was not significantly different from that of fish fed 55% CP diet, but significantly higher (P<0.05) than that of fish fed 30, 40, 45 and 60% CP diet. Also, a broken-line model analysis for weight gain indicated that the optimum dietary protein level was 50±3.7% (mean±SD). Fish fed 50% CP also had the highest feed efficiency and hepatosomatic index. Condition factor increased with dietary protein level. No significant differences existed in haematocrit, hemoglobin and survival rate among the dietary treatments. Therefore, these findings suggest that the optimum protein level is approximately 50% of dry diet for maximum growth in juvenile yellow puffer.
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  • Cyril Glenn Satuito, Kazuyo Natoyama, Mizue Yamazaki, Katsuhiko Shimiz ...
    1999 Volume 65 Issue 3 Pages 384-389
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Effects of neuroactive compounds on the metamorphosis of pediveliger larvae of the mussel Mytilus galloprovincialis have been examined. Among the compounds tested, carbamylcholine and epinephrine both induced high percentage metamorphosis to post larvae. Norepinephrine, L-DOPA and serotonin were less active inducers of metamorphosis. These inducers were found effective at 10 μM, except for serotonin which significantly induced metamorphosis at 100 μM. By contrast, L-DOPA exhibited toxicity at 100 μM. Efficacy of the inducers varied with exposure time. Epinephrine was a fast acting inducer of metamorphosis; 3h exposure efficiently yielded maximum results. On the other hand, efficacy of carbamylcholine as inducer increased with longer exposure time.
    Among the 5 vertebrate adrenergic antagonists tested, phentolamine significantly blocked the metamorphosis inducing activity of epinephrine. However, WB4104, yohimbine and propranolol all exhibited agonist activity in the absence of epinephrine.
    These results suggest that use of neuroactive compounds may provide an effective and inexpensive
    method to control settlement and metamorphosis of mussels.
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  • Joebert D. Toledo, Ma. Salvacion Golez, Masanori Doi, Atsushi Ohno
    1999 Volume 65 Issue 3 Pages 390-397
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Newly-hatched Epinephelus coioides larvae were stocked in five 5-ton tanks at an initial density of 25, 000 ind/tank. Copepod nauplii were propagated in four of these tanks by inoculating various densities (20 to 80 ind/ι) of mixed copepodids of Acartia tsuensis, Pseudodiaptomus spp., and Oithona sp. three days before stocking larvae. Rotifers were added in these tanks on Day 7 at an initial density of 5, 000 ind/ι. Larvae in the remaining tank were fed rotifers (only) starting Day 2 at 5, 000 ind/ι. The feeding incidence, gut content, growth, and survival of larvae were better in tanks with higher density of copepodids (60-80 ind/ι). These indices were lowest in larvae given rotifers only. Total n-3 HUFA of copepods was 2 to 3 times higher than rotifers. High percentages of 22:6n-3 (DHA) were detected in the fatty acid composition of Pseudodiaptomus (13%) and Acartia (24%) with DHA/EPA (20:5n-3) values of 1.4 and 2.6, respectively. By providing nauplii of copepods at the early feeding stage, an average survival of 3.4% at harvest (Day 36) was obtained in a pilot scale grouper seed production trial in three 10-ton tanks.
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  • Frangky Erens Kaparang, Yasuhisa Matsuno, Yuichi Yamanaka, Shigeru Fuj ...
    1999 Volume 65 Issue 3 Pages 398-404
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The differences between swimming and feeding activity of recorded underwater sound in summer and winter produced by Japanese horse mackerel in a net pen were analyzed using the one-third octave band method. The small and big-sized fish show the same curve patterns under swimming and bait-eating activity in summer, but in the term of the maximum and minimum level frequencies, it seems slightly different. The swimming sound curve pattern in summer was same as in winter, but there were some different patterns in bait-eating sound. The two respective records obtained simultaneously on the inside and outside of net pen when swimming activity were same in regard to the pattern and sound level, but the records when bait-eating activity were different.
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  • Takashi Yada, Fuminari Ito
    1999 Volume 65 Issue 3 Pages 405-409
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    To investigate endocrine control of osmoregulation in the fish under acidic environment, sodiumretaining effects of cortisol, prolactin and estradiol-17β were examined in the acid-exposed medaka Oryzias latipes. Exposure from neutral fresh water (pH 7.0) to acidic fresh water (pH 3.8) for 24h caused a significant decrease in plasma sodium levels in both sexes of the medaka. Single injection of cortisol prior to the exposure retained plasma sodium levels and stimulated gill Na+, K+-ATPase activity in acid water. Ovine prolactin also prevented a decrease in plasma sodium levels after acid exposure, whereas gill Na+, K+-ATPase activity was unaffected. In male fish, estradiol-17β prevented a decrease in plasma sodium level without affecting gill Na+, K+-ATPase activity. On the other hand, estradiol17β had no effect on plasma sodium in female fish. There was no additive action of estradiol-17β on the prolactin-stimulated retention of plasma sodium levels in male fish. These findings showed that cortisol and prolactin have sodium-retaining activity in acid-exposed medaka of both sexes, and estrogen seems to involve in the sex difference in acid tolerance.
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  • Liu Xuezhen, Masahiko Furusawa, Etuyuki Hamada, Chiharu Aoyama
    1999 Volume 65 Issue 3 Pages 410-419
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    A basic designing method of the acoustic transmitting-receiving system for measuring or utilizing volume backscattering of zooplankton is developed, applying the method established for the quantitative echo sounder design. The primary principle is to make the signal-to-noise ratio in measuring volume backscattering strength of zooplankton as high as possible by selecting appropriate parameters such as frequency, beam width, etc. The scattering property of zooplankton applied is Johnson's highpass liquid sphere model. The frequency characteristics of the signal-to-noise ratio are derived combining the scattering model and several characteristics of sound transmission and reception. A universal diagram for basic design of transmitting-receiving system, which shows all relationships in the observation range, the plankton size, the signal-to-noise ratio, the frequency, the beam width and the diameter of transducer, is made. Suitable range of the frequency, maximum depth range, etc. can be easily found at a glance from this diagram. The method is experimentally examined using the field data obtained by a Doppler current meter. The results show that the experimentally observed signal strength is nearly equal to the predicted one. The signal-to-noise ratio is further discussed using the noise level observed during the experiment.
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  • Gen Kume, Atsuko Yamaguchi, Toru Taniuchi
    1999 Volume 65 Issue 3 Pages 420-423
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The feeding habits of Apogon lineatus in Tokyo Bay were examined based on 677 specimens. The vacuity index was relatively high (26.1%). The diet of the fish was composed primarily of shrimps (frequency of occurrence (%F), 76.2; weight percentage (%W), 73.9; ranking index (RI), 5631), especially Crangon affinis (%F, 59.2; %W, 56.2; RI, 3327). Fishes (%F, 5.9; %W, 4.2; RI, 25), including Chaeturichthys sciistius, were also found in the diet. Shrimps were found to be important throughout the year. However, conspeciflc egg masses with the surfaces digested were observed in the stomachs of many males during the breeding season. This finding suggests that this species engages in filial cannibalism.
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  • Yukio Ueta, Tadashi Tokai, Susumu Segawa
    1999 Volume 65 Issue 3 Pages 424-431
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Relationship between year-class abundance of the oval squid Sepioteuthis lessoniana and selected environmental factors are examined using multiple linear regression analysis to predict landings. Landings from April to August, an index of spawning stock size, had no relationship (r=-0.123) with the landings during the subsequent September to December as a recruitment index. This implies that no relationship between spawning-stock and recruitment occurs in this species. Landings from September in a given year to the next August were employed as an index of the year-class abundance in the year (criterion variable, Y). Average monthly values of four environmental factors during the period from April to September which includes the spawning and hatching season and the early life period of this species were examined as explanatory variables: water temperature (X1) and salinity (X2) at 10m depth; and atmospheric pressure (X3) and rainfall (X4) measured in Tokushima City. The year-class abundance were expressed as Y=-329 7.4+37.OX1+79.9X2. From the multiple regression equation with environmental data from April to September, year-class landings are predictable. The year-class landings is closely related to the water temperature with salinity during April to September. High water temperatures and high salinities during this period are associated with successful recruitment.
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  • Ryuji Kondo, Ichiro Imai, Kimio Fukami, Akiko Minami, Shingo Hiroishi
    1999 Volume 65 Issue 3 Pages 432-435
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Sequencing the 16S rDNA and phylogenetic analysis were performed on algicidal bacteria belonging to the family Flavobacteriaceae, Chattonella-killing Cytophaga sp. strain J18/M01, Heterocapsa-killing Cytophaga sp. strains AA8-2 and AA8-3, and Gymnodinium growth-inhibiting Flavobacterium sp. strain 5N-3. These algicidal strains were clustered phylogenetically within the marine Cytophaga/Flavobacter/Bacteroides (CFB) group. Flavobacterium sp. 5N-3 was phylogenetically clustered with Psychroserpens burtonensis but not with the algicidal gliding bacteria. The sequence similarity between strain 5N-3 and P. burtonensis was only 92%. The strains J18/M01 and AA8-2 (AA8-3) exhibited the high level of sequence similarity of 98.5%. Despite the differences of host algae and of locality and year of isolation, these algicidal bacteria were phylogenetically located on the same terminal branch.
    The PCR amplification of the 16S rDNA of the CFB strains using a single set of J18/M01-specifk primers resulted in specific detection of the J18/M01, indicating that the J18/M01-specific sequence in the 16S rDNA is useful for selective detection of the strain J18/M01.
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  • Daiju Oki, Osame Tabeta
    1999 Volume 65 Issue 3 Pages 436-440
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    A total of 2, 863 specimens of big eye Priacanthus macracanthus caught by bull trawl in the East China Sea and landed at the Nagasaki Fish Market from May 1995 to February 1998, were examined to obtain information on age structure and growth rate. Ages were determined using mesopterygoid readings. Mesopterygoid length was measured from the focus to the outer margin along a line perpendicular to the sagittal plane of the body. The fork length to mesopterygoid length relationship was significantly different between males and females. Based on evidence from monthly changes of marginal increments, marks on the mesopterygoids were formed twice a year in June and January. From the monthly changes of GSI, a spawning peak is estimated to occur in May and June. Growth equations are given for each sex. Females are larger than males, and differences in mean fork length between males and females increased with growth. The calculated fork lengths at age in the present study approximate a previous report based on total length frequency distributions from the East China Sea, and were larger than these reported from waters northeast and southwest of Taiwan and smaller than for the Indian Ocean.
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  • Maricar Prudente, Hideki Ichihashi, Supawat Kan-atireklap, Izumi Watan ...
    1999 Volume 65 Issue 3 Pages 441-447
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Contamination by butyltins (BTs), organochlorine compounds (OCs) and heavy metals was examined in green mussels collected along the coastal areas of the Philippines in 1994 and 1997. Significant BTs concentrations revealed widespread contamination along nearshore marine waters. Relatively high BTs concentrations were observed in samples collected from areas with high boating activities, suggestive that the source of TBT (tributyltin) is coming from antifouling paints. While TBT levels were found to be low in green mussels collected from aquaculture areas, implying minimal usage of BTs for aquaculture activities. The composition of BT derivatives in mussel was in the order of TBT>DBT>MBT, reflective of continuous input of TBT in the coastal waters. Considering the unregulated use of organotins in the country, BTs contamination in the aquatic environment of the Philippines may increase in the future. Concentrations of OCs in green mussels were less than BTs. Among OCs, PCBs concentrations were found to be relatively high particularly in mussels from Manila Bay. Moreover, metal concentrations found suggest that the anthropogenic loading of Hg, Pb and Cd to the coasts is relatively low, suggestive that the green mussels from these coastal waters are not adversely affected by these metal toxicants and pose no risk for human health. To our knowledge, this is the first comprehensive report on the concentrations of butyltins, organochlorine compounds and heavy metals in soft tissues of ereen mussels in the Philippines.
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  • Tadashi Tokai, Yukio Ueta
    1999 Volume 65 Issue 3 Pages 448-454
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    This paper examines size selectivity in the squid jigging fishery for the oval squid Sepioteuthis lessoniana in Tokushima Prefecture using an extended SELECT model for analyzing size frequency distributions of squid caught by the squid jigging and by set nets. The SELECT model is extended to utilize size frequency distributions constructed from repeat measurements of catch in the squid jig as the test gear and the set nets as the control gear where data on the fishing efforts is not available with variable fishing efficiencies. As a result, size selectivity r(ι) of squid jigs of a body size from 12 to 15cm is expressed as a logistic function of the mantle length ι, r-(ι)=exp(-10.0+0.485ι)/[1+exp (-10.0+0.485ι)]. This equation indicates that oval squid of a size smaller than the jig is not caught by the jig. As the squid attacks the jig as a prey, the size selectivity of the squid jig found here is a type of prey size selectivity.
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  • Yumiko Azuma, Kunihiko Konno
    1999 Volume 65 Issue 3 Pages 455-458
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Denaturation process of carp subfragment-1 (S-1) during frozen storage at -20°C was investigated by comparing with thermal denaturation. Frozen storage of S-1 inactivated the Ca2+-ATPase activity, while the S-1 solution exhibited no turbidity. Centrifugation of the frozen S-1 sedimented a very small amount of S-l demonstrating that inactivated S-1 was still soluble. Sepharose CL-4B gel filtration demonstrated that the inactivated S-1 by freezing was eluted at the ascending part of single peak of S-1 indicating that a very small structural change was brought about by inactivation. The inactivated S-1 by freezing still retained light chain binding ability. These were completely different from those observed with thermally denatured S-1. Thus, freeze denaturation of S-1 was characterized by the retained LC binding ability resulted in a prevention of aggregate formation. Tryptic digestion of frozen S-1 revealed that inactivated S-1 was unspecifically cleaved into short pieces.
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  • Takao Ojima, Tomoyuki Higuchi, Kiyoyoshi Nishita
    1999 Volume 65 Issue 3 Pages 459-465
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    Reversibility of unfolding of α-helix in walleye pollack light meromyosin (LMM) by heat-treatment was investigated by circular dichroism spectrometry and α-chymotryptic digestion. By increasing the temperature from 5 to 50°C, α-helix content of the LMM was decreased from 88% to 15% with a major and a minor transition at around 28°C and 40°C, respectively. On the other hand, α-helix content of the LMM was increased from 15% to 68% by decreasing the temperature from 50°C to 5°C, while it was not fully recovered to the original value, suggesting that some α-helical portions were irreversibly unfolded by heating. Therefore, the LMM was heated at 50°C for 5 min, cooled to 0°C, and then digested with α-chymotrypsin to assign the reversible and irreversible unfolding regions. As a result, the 42-kDa fragment and some smaller peptides which were hardly formed by the digestion of unheated LMM were newly formed. The 42-kDa fragment was identified as an N-terminal 2/3 region of the LMM by the amino acid sequencing of both N- and C-terminal regions, while most of the smaller peptides were derived from the C-terminal 1/3 region of the LMM. The 42-kDa fragment showed 90% α-helix content and its unfolding upon heating was almost reversible unlike the original LMM. From these results, we propose that the N-terminal 2/3 and C-terminal 1/3 regions of the pollack LMM are reversiblv and irreversibly unfolding regions, respectively, by the heat-treatment.
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  • Yuki Tokuda, Ken Touhata, Masato Kinoshita, Haruhiko Toyohara, Morihik ...
    1999 Volume 65 Issue 3 Pages 466-471
    Published: 1999
    Released on J-STAGE: June 30, 2008
    JOURNAL FREE ACCESS
    The cDNA of the glucocorticoid receptor (GR) has been isolated from Japanese flounder liver and sequenced. The cDNA contained a complete open reading frame encoding 807 amino acid residues. The structural homology indicated that the Japanese flounder GR (jfGR) was divided into six different regions, A to F. Comparison of these regions of jfGR to those of rainbow trout GR showed a homology of 37% for A/B region, 98% for C region, 53% for D region, 93% for E region, and 82% for F region. Especially, eight cysteines in two zinc-fingers and the P-box in C region (DNA binding domain) were completely conserved. However, it contained an additional 9 amino acids insertion (WRARQNTDG) between the two zinc fingers which was previously detected in rainbow trout and eel GRs. Such insertion reported here could be for only fish GRs among any of steroid hormone receptors, suggesting that this amino acid insertion was a specific feature of fish GRs.
    The trans-activation function of this clone was verified by transfection into COS-7 cell, whichlacks endogenous GR. A CMV-based expression vector consisting of jfGR cDNA was cotransfected with a reporter plasmid consisting of an glucocorticoid-responsive element fused to the chloramphenicol acetyl transferase (CAT) gene. As a result, the expression of CAT protein was stimulated by the addition of dexamethasone or cortisol. This evidence showed that this clone encoded the functional receptor.
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  • Abdul Jabarsyah, Mutsuyosi Tsuchimoto, Yasutoshi Kozuru, Tosio Misima, ...
    1999 Volume 65 Issue 3 Pages 472-477
    Published: 1999
    Released on J-STAGE: June 30, 2008
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    As a part of study programs on the rigor mortis progress in fishes, we tried to clarify the influence of pink muscle fiber in dorsal ordinary muscle on the rigor mortis progress. Muscle fiber types in dorsal ordinary muscle of several fishes were discriminated by inactivation of actomyosin ATPase after acid and alkaline preincubations, and rigor mortis with the lapse of time, was measured in the pillar form of dorsal muscle.
    The pink muscle fiber was found in the ordinary muscle of many sample fishes and it was recognized in mosaic pattern among white muscle fibers. The muscle fiber types were found as follows: pink muscle fiber (P) and white muscle fibers (W) of Ha and lib like subtypes {P+W(IIa+IIb)}, pink muscle fiber and white muscle fiber of IIa or lIb like subtype {P+W(IIa or lIb)}, white muscle fibers of Ha and lIb like subtypes {W(IIa+IIb)}, and white muscle fiber of Ila or lIb like subtype {W(IIa or lIb)}. The rigor mortis progress in fishes organized from P+W(IIa+lIb) or P+W(IIa or lIb) were considerably higher in response to the maximum level reached than that in the fishes from W(IIa+lIb) or W(IIa or lib). This phenomenon was consistent in fishes composed of pink and white muscle fibers. Therefore, it was considered that the presence of the pink muscle fiber in the dorsal ordinary muscle might influence the rigor mortis progress.
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  • Takafumi Shikata, Koji Shirata
    1999 Volume 65 Issue 3 Pages 478-481
    Published: 1999
    Released on J-STAGE: June 30, 2008
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    Changes in the mantle muscle acid protease activity and the thickness of the mantle with sexual maturation were investigated in female Japanese common squid Todarodes pacificus from the Sea of Japan. The thickness index of the mantle was significantly lower in mature squid than in immature squid, and it decreased with an increase in gonadosomatic index, indicating that the mantle became thinner with maturation. The mantle muscle acid protease activity was significantly higher in mature squid than in immature squid, and it increased with a thinning of the mantle. In contrast to the acid protease activity, the mantle muscle protein content showed a tendency to decrease with a thinning of the mantle. These results suggest that the thinning of female squid mantle during sexual maturation is ascribed to the enhanced protein breakdown in the mantle muscle.
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  • Tatsuya Kaji, Masaru Tanaka, Masatomo Tagawa
    1999 Volume 65 Issue 3 Pages 482-483
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Noritaka Hirazawa, Takashi Hara, Jiro Okazaki, Kazuhiko Hata
    1999 Volume 65 Issue 3 Pages 484-485
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Motohiro Takagi, Kazunori Yoshida, Nobuhiko Taniguchi
    1999 Volume 65 Issue 3 Pages 486-487
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • In-Seok Park, Chi-Hong Kim, Dong Soo Kim
    1999 Volume 65 Issue 3 Pages 488-489
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Takayuki Ashida, Eiji Okimasu, Akinori Amemura
    1999 Volume 65 Issue 3 Pages 490-491
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Toyoji Kaneko, Sanae Hasegawa
    1999 Volume 65 Issue 3 Pages 492-493
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Kentaro Agatsuma, Junichi Sugiyama, Satoru Nishinaka, Junji Kimura
    1999 Volume 65 Issue 3 Pages 494-495
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Masaharu Tokuda, Masaaki Takeuchi
    1999 Volume 65 Issue 3 Pages 496-497
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Hidehiro Kondo, Ichiro Kawazoe, Misako Nakaya, Kiyoshi Kikuchi, Katsum ...
    1999 Volume 65 Issue 3 Pages 498-499
    Published: 1999
    Released on J-STAGE: June 30, 2008
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  • Miyuki Tsushima, Takao Matsuno
    1999 Volume 65 Issue 3 Pages 500-501
    Published: 1999
    Released on J-STAGE: June 30, 2008
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