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Volume 46, Issue 2
Displaying 1-20 of 20 articles from this issue
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Daiju OKI, Osame TABETA1998 Volume 46 Issue 2 Pages 165-169
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSA total of 762 specimens of big eye, Priacanthus macracanthus caught by bull trawl in the East China Sea, were examined to obtain information about the validity of hard tissues as age indicators. Of the 12 hard tissues examined, including scale, otolith and vertebra, growth marks on the mesopterygoid were most clearly recognized. Mesopterygoid length was measured from the focus to the outer margin along a line perpendicular to the sagittal plane of the body. The percentage of specimens for which growth marks were able to be measured in the present study was higher than the percentage reported in a previous study in which scales were used. The relationship between the fork length and the mesopterygoid length was highly correlated, and it is clear that the growth increments corresponded to equal time intervals from the WALFORD's diagram. We conclude that mesopterygoids are valid age indicators.View full abstractDownload PDF (3301K) -
Tianxiang GAO, Seiichi WATANABE1998 Volume 46 Issue 2 Pages 171-176
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSHorizontal starch gel electrophoresis was used to analyze the genetic relationship between the Japanese mitten crab, Eyiocheir japonica and its congener Chinese mitten crab, E. sinensis. Twenty two putative enzyme-coding loci were examined using muscle of 1072 Japanese mitten crabs and 69 Chinese mitten crabs. Three loci were found polymorphic in Japanese mitten crab, i.e. AAT-1*, GPI*, and IDHP-1*, and four loci in Chinese Mitten crab, i.e. AAT-2*, G3PDH*, GPI*, and IDHP-1*. The proportion of polymorphic loci and heterozygosity were 0.136 and 0.020 for Japanese mitten crab, 0.182 and 0.034 for Chinese mitten crab. There were significant difference at allele *a of locus AAT-2*, allele *a, **c, **d of locus GPI* and locus IDHP-1*. The Nei's genetic distance between the two species was 0.051, which was much bigger than the average distance among the 22 Japanese mitten crab populations.View full abstractDownload PDF (781K) -
Kiyoshi YOSHIHARA, Sanae KURAKATA, Chinatsu FUJITA, Masako YANAGIHARA, ...1998 Volume 46 Issue 2 Pages 177-182
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSTagging experiment were carried out for a better understanding of the movement and growth of juvenile nibbler Girella punctata Gray at the Tanoura inlet and it's surrounding waters, Shimoda, Shizuoka Prefecture. A total of 6, 834 juvenile nibblers caught were tagged by binary coded wire tag and released in the period from March to September in 1996 and 1997. Of them, 78 and 51 fishes were recaptured and could discriminate each individual in 1996 and 1997, respectively. The majority of fishes were recaptured near the released point, except for point TC, over two years. This fact suggested that the juvenile fishes of less than 3 cm in body length could not move from the releasing point to the captured point, TC by traversing the inlet. A juvenile, which had been caught at P1, 650 m away from the released point, was recaptured again at the same point 5 days after the release. This indicated that the juvenile fish moves at the rate of 130 m/day. Moreover, other juvenile grew from 2.0 cm to 9.3 cm for 300 days. The regression equations between lapsed days (t) and body length (L) or body weight (W) can be expressed as Lt =19.227 {1-exp (-0.0018t-0.1036) } in body length, and Wt=0.0233 t 1.123 in body weight.View full abstractDownload PDF (806K) -
Kenji YOSHIMURA, Koji USUKI, Takao YOSHIMATSU, Kenji TANAKA, Ayaaki IS ...1998 Volume 46 Issue 2 Pages 183-192
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSFor the reliable process management of high density culture of marine rotifer Brachionus rotundiformis, it is very important to know the quantitative behavior of rotifer biomass, the concentrations of particulate organic matters including nutritional organic matters for rotifer, and total ammonia (NH4-N) . In this study, changes in dry weight, PV (packed volume) and population of rotifer, PV of particulate organic matters and concentrations of NH4-N in high density semicontinuous culture were investigated. High density culture was performed by supplying oxygen from a generator, controlling the pH at 6.7 and feeding condensed Chlorella regularis at a feed rate of 4.2 kg/day with a peristaltic pump. Filtration unit was also used to remove the excess amount of particulate organic matters (mainly bacterial flocs and films) from culture medium. Total amount of accumulated Chlorella (Rn, g) in the culture tank was expressed with the feed rate of Chlorella (S, g/day), culture day (n) and harvest rate (T) as follows.
Rn= {1- (1-T) n} / {1- (1-T) } ⋅S
The amount of NH4-N produced (Yn, g) and the concentration of NH4-N in culture medium (An, ppm) were estimated by following exprimental formulas. where a is the initial ammonia concentration (ppm) and V is working volume (kl) .
Yn= 0.0326 Rn (r=0.95, p<0.01)
An=a⋅ (1-T) n+Yn/V
The result of partial correlation analysis for the PVs of rotifer, wastes layer, and microbial layer and culture day indicated that the wastes layer was utilized by rotifer as feed but microbial layer was not utilized. As the result of multiple regression analysis, it was proved that the measurement of PV was more reliable among the methods for quantitative determination of rotifer biomass. The measurement of PV can be easily performed by the centrifugation of culture medium, therefore PV monitoring will be very useful for on-line management of high density culture of rotifer. In the semicontinuous high density culture of 20 days, the feed conversion rate of Chlorella to rotifer was found to be 23.5% (w/w) . Dry weight and PV per rotifer individual were estimated to be 1.6 × 10-7 g and 9.2 × 10-7 ml, respectively, and those per rotifer egg were 0.9 × 10-7 g and 4.9 × 10-7 ml, respectively.View full abstractDownload PDF (1605K) -
Koji USUKI, Kenji YOSHIMURA, Takao YOSHIMATSU1998 Volume 46 Issue 2 Pages 193-201
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSIn the high density culture process of rotifer Brachionus yotundiformis fed on fresh water Chlorella, the bacterial counts of the rotifer were 109 CFU/g on ZoBell's 2216E agar, 105-106 CFU/g on TCBS agar, and those in the culture media were 106-109 CFU/ml and 103-106 CFU/ml, respectively. These bacterial counts were always ten to one hundred times greater than those recorded from conventional rotifer culture method usingNannochloropsis as feed. Moreover, these counts showed no change in number during the secondary culture of rotifer for EFA-enrichment; 109 CFU/g on ZoBell's agar and 105-106 CFU/ml on TCBS agar. The effect of sodium nifurstyrenate (NS) bathing on controlling the bacterial bloom in the high density rotifer culture was investigated. As results, the bacterial counts of rotifer decreased to one tenth of that on the ZoBell agar and one tenth to one hundredth of that on the TCBS agar when 2-10 ppm NS was added to the secondary culture medium together with the enrichment. Nevertheless there were no differences in bacterial counts in rotifer when NS was added directly to the primary culture medium.View full abstractDownload PDF (1402K) -
Keitaro KATO, Osamu MURATA, Takashi NAKAARAI, Toshiro NASU, Shigeru MI ...1998 Volume 46 Issue 2 Pages 203-212
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSGenetic variability, external morphology, growth, and feed efficiency under different feeding conditions were compared between selected and non-selected strains of red sea bream. (1) Although the extinction of low frequency alleles in the selected strain was suggested, differences in the average heterozygosities observed (Ho) and the ratio of the average heterozygosity observed to the one expected (Ho/He) between the selected and non-selected strains were not recognized. In addition, the results of heterogeneity tests for allele frequencies at 5 polymorphic loci show the population genetic difference between the selected and non-selected strains. (2) The caudal and pectoral fins of the selected strain are smaller than those of the non-selected strain. Thus, the swimming ability of the selected strain may not be as good as that of the non-selected strain. (3) The feeding rate, weight gain, feed efficiency, protein efficiency ratio, and digestibility of the selected strain were higher than those of the non-selected strain in the case of satiation feeding, and the fish of the selected strain have a greater ability to utilize diet lipids and accumulate diet proteins during restricted feeding.View full abstractDownload PDF (1406K) -
Yasuhisa KAYANO, Ho Yung WAN, Takashi HARA, Taketo FUKUNAGA1998 Volume 46 Issue 2 Pages 213-218
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSIn order to obtain optimum Broodstock age for seed production of red spotted grouper, Epinephelus akaaya, quantity and quality of naturally spawned eggs were compared within two age-class groups. In the Broodstock of older (about 10-15 years) and younger (about 3-5 years) groups, the amount of eggs produced during the spawning period averaged 2, 480 × 103 and 1, 390 × 103 eggs per fish, respectively. The buoyancy egg of the older group was higher than the younger group. The average egg diameter decreased as spawning progressed in both groups. While, the average egg diameter of the younger group was larger than that of the older group. The hatching rate and the abnormality of hatched larvae varied with spawning days. The survival activity index of starved larvae of the younger group showed higher than that of the older group. Contents of amino acid and lipid of the eggs in the younger group were higher than that of the older group. While, the percentage of n-3HUFA in fatty acid content of the eggs in the older group was higher than that of the younger group, it may be associated with the difference of feed quality. The results demonstrated that the egg quality of red spotted grouper is affected by the Broodstock age and the larvae from a large egg will be a better survivor on account of having a lot of energy source.View full abstractDownload PDF (841K) -
Kyoko SHIMAMURA, Mikio NAKAMURA1998 Volume 46 Issue 2 Pages 219-224
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSSeaweed and seagrass communities were observed on the coast of Lake Nakaumi, Brakish water, Shimane, Japan. A total of 22 species of seaweeds and seagrasses were found on the coast. Their distribution and growing condition were influenced by the environmental factors of water, such as salinities (19.9-29.9 PSU) and illumination (0.4-24.0 klx at bottom) . Seaweed and seagrass communities were found only at depth of 0-3m in the study area, as the transparency was very lower. Particularly the transparency was lower at the southern part of Lake Nakaumi. The seaweed flora showed the species of a inlet type and the euryhaline species that tolerance to salt. The dominant species in the Lake Nakaumi were Sargassum thunbergii, Ulva pertusa, Gracilaria asiatica, and Zostera japonica.View full abstractDownload PDF (659K) -
Wazir Ali BALOCH, Hiroshi SUZUKI, Yoshio ONOUE1998 Volume 46 Issue 2 Pages 225-229
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSCyclomorphosis of Bosmina longirostris was monitored in Lake Ikeda, Southern Kyushu, Japan from July 1993 to June 1994 and in February and June of 1995 and 1996. B. longirostris showed a marked cyclomorphosis in the lake; an increase in body size and lengths of the antennule and mucro in winter and a decrease in these characters in summer. Cyclic changes in body size and protuberant structures were negatively correlated with water temperature of the lake except the density of a copepod Mesocyclops species. The body length, on the other hand, was positively correlated with the antennule and mucro lengths. The protuberant structures were found coupled and positively correlated with each other. Predation and/or food availability, however, were not correlated with the cyclomorphosis of Bosmina population in the lake.View full abstractDownload PDF (648K) -
Satoshi YAMAMOTO, Yoshihiro SAWAMOTO1998 Volume 46 Issue 2 Pages 231-236
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe physical environment of the microhabitat used by Japanese sculpin (river residence type), Cottus pollux, was examined through field observations in Chikuma River. Large individuals (>7 cm TL) were found in microhabitats at depth of 40-50 cm with a mild current velocity (20-40 cm/sec) . They used rubble (>20 cm diameter) as a hiding place, however size selection of the cover was not significance. Small individuals (<2cm TL) were found in microhabitats at less than 20 cm depth, with a slow current velocity (<20 cmisec) and fine sediments (<3.5cm diameter) in the river ground. The results indicate that Japanese sculpin varied its microhabitat as its body size increased.View full abstractDownload PDF (793K) -
Haruo SUGITA, Ryuji OKANO, Takayuki ISHIGAKI, Eiji AONO, Nobuhiko AKIY ...1998 Volume 46 Issue 2 Pages 237-241
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSMicroflora in seawater of glass aquaria (47 l in capacity) equipped with the recirculating water system, in which five to 10 juveniles of Japanese flounder, Paralichthys olivaceus, were stocked, were investigated. Flavobacterium, Moraxella and Pseudomonas were predominant in almost all samples with densities of 6.9×102 to 7.6×104 CFU/ml. In contrast, genus Vibrio appeared immediately after the fish were introduced. It became predominant at densities of 1.3×103 to 3.4×104 CFU/ml and decreased slightly after removal of fish. Both micro-bound and pelleted diets contained only Gram-positive bacteria at densities of 6.9×105 to 8.1×105 CFU/g. Intestinal contents of Japanese flounder were colonized only by Vibrio at densities ranging from 1.9×106 to 1.1×109 CFU/g. These results strongly suggested that genus Vibrio appeared in seawater of flounder-rearing aquaria was derived from fish intestines. Furthermore, the results demonstrated that microflora of seawater is significantly influenced by fish culture.View full abstractDownload PDF (739K) -
Jean B. TANANGONAN, Hiroshi NAKANO, Masaru TANAKA1998 Volume 46 Issue 2 Pages 243-252
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSEggs and larvae of Japanese flounder Paralichthys olivaceus reared at 22°C were analyzed for DNA, RNA, and protein content. At hatching, larvae contain more DNA and RNA than fertilized eggs, but protein content is lower. Protein/DNA and RNA/DNA ratios of eggs sharply decreased at hatching and continued to decrease until the first feeding. From hatching to early juvenile stage at age 41 days, mean DNA, RNA, and protein content of individual larvae increased with age and length. The protein/DNA ratio generally increased with age and length after the start of feeding (stage A), while the RNA/DNA ratio increased to a maximum at the early phase of metamorphosis (stage F), sharply dropped at the mid-metamorphosis (stage G), and increased again until the end of the experiment. From hatching to the end of experiment, the RNA/DNA ratio averaged 5.0. The fluctuations in RNA/DNA ratio at stages F and G may indicate changes in metabolic activity related to metamorphosis. Protein/DNA and RNA/DNA ratios slightly decreased when larvae became benthic juveniles at age 28 days (stage H) . Changes in nucleic acid and protein contents as well as in protein/DNA and RNA/DNA ratios indicate that transfer from endogenous to exogenous nutrition, metamorphosis and settlement are critical ontogenetic events during the early life history of the Japanese flounder.View full abstractDownload PDF (1309K) -
Masayuki YOSHIKAWA1998 Volume 46 Issue 2 Pages 253-259
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSDosage effect of L-ascorbic asid (AsA) and α-tocopherol (Toc) on their distribution and accumulation in Japanese eel, Anguilla japonica during the induced maturation were examined (n=1) . One group received AsA and Toc 5 mg/100 gBW /week (1st group) and another group received salmon pituitary 20mg/fish/week in addition to AsA and Toc (2nd group) . As for AsA, the result showed that in the 1st group AsA was distributed both in the ovary and the liver, but mainly in the ovary. In the 2nd group, however, AsA was distributed only in ovary. In addition, salmon pituitary did not improve eel's capacity for AsA absorption. The percentage of administrated AsA accumulated in eel's body was about 10%. As for Toc, although generally there was little Toc in liver, when eel received a lot of Toc the amount of Toc in liver increased very much. In both the 1st and the 2nd group administrated Toc was mostly distributed to muscle in eel's body. In the 2nd group more Toc was distributed to ovary than in the 1st group; however, the amount of Toc in the muscle and the liver in the 2nd group was not different from that in the 1st group, i.e., in the 2nd group the increased amount of the absorbed Toc was all distributed to the ovary. Salmon pituitary had an effect on improvement of eel's capacity for Toc absorption. The percentages of administrated Toc accumulated in eel's body were 40% in the 1st group and 50% in the 2nd group, respectivly. The reason of this high percentage was thought that administrated Toc dissolved in the fat that abundantly existed in eel's body.View full abstractDownload PDF (1186K) -
Masayuki YOSHIKAWA1998 Volume 46 Issue 2 Pages 261-267
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSDistribution and accumulation of L-ascorbic acid (AsA) and α-tocopherol (Toc) in Japanese eel, Anguilla japonica during the induced final maturation were examined. AsA and Toc (5 mg/100 gBW/week respectively) were administrated to the eel at the times when 20 mg/fish/week salmon pituitary glands were given to induce the final maturation. The result showed that with AsA administration the AsA level in the ovary at the final maturation was higher. During the final maturation, in the eel without AsA administration, most of AsA was distributed to the ovary and little was distributed to the liver and the muscle, but in the eel with AsA administration, certain amount of AsA was also found distributed to the muscle. As for the distribution of Toc at the final maturation, with Toc administration, Toc was mainly accumulated in the muscle, ovary and liver; The amount of Toc in the ovary increased and equaled that in the muscle. Without Toc administration, individually the Toc amount in the muscle was the same or slightly higher compare to that in the ovary. I concluded that the distributions of AsA and Toc in eel's body at the final maturation were different from each other and AsA was more concentrated in ovary than Toc.View full abstractDownload PDF (1053K) -
Stimulatory Effectiveness of Aqueous Extract of Shrimp Shell for Olfactory Response in Red Sea BreamHiroshi KOBAYASHI, Yoshinari ISHIDA, Sadashi SHIRAZAWA1998 Volume 46 Issue 2 Pages 269-272
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSElectro-olfactogram (EOG) of the red sea bream, Pagrus major, was recorded with calomel electrodes via Ringer-agar filled capillary pipettes. Using the EOG response, the effect of aqueous extract from the shell of the shrimp, Metapenaeopsis barbata, on the fish olfaction was investigated. The extract of shrimp shell showed equally well EOG responses as that of muscle, even at a low concentration of 10-2 gram percentage. The stimulus effectiveness of shell extract of the shrimp on fish olfaction suggests an possibility of utilizing the shrimp shell for feeding or attractant in aquaculture.View full abstractDownload PDF (554K) -
Katsuhiko HARADA, Taiko MIYASAKI, Hiroshi MAEDA, Kohji SATOH1998 Volume 46 Issue 2 Pages 273-277
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe multiple linear regression equations of attraction activity on the proximate components in the 12 fishing baits were estimated for seeking probable feeding attractive components for yellowtail, Seriola quinqueradiata. The attraction activity was expressed as the attraction index gr (apparent individual numbers entered at the time a), the product of coefficients g and r in a logistic curve y=g/ {1+exp [-r (x-a) ] } estimated by applying the time-course of the number of individuals entered into the test compartment to the curve. The proximate components determined were moisture, ash, protein, lipid, carbohydrate, and extractive. The multiple linear regression equation of the attraction index on the contents of ash, protein, lipid, carbohydrate and number of individuals used in the respective experiments revealed that the index increased with the contents of protein and the index might also be related to the contents of lipid.View full abstractDownload PDF (605K) -
Yasuyuki HASEGAWA, Toshio TAKEUCHI, Emiko ITAGAKI, Tatsuhiro FUKUNAGA1998 Volume 46 Issue 2 Pages 279-286
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThis experiment was conducted to clarify the relationship between fat soluble vitamins (vitamins A and D) in diet and the occurrence of colour abnormality on the blind side of juvenile Japanese flounder, Paralichthys olivaceus. Twenty days after hatching, fish were fed the experimental diets containing three different levels of vitamin A (0, 1, 500, and 9, 000 IU/100g) in addition to 20, 000 IU vitamin D, apart from two others commercial diets (X and Y), the basal ingredients and compositions of the experimental diets and the commercial diet X are the same. When the fish reached 30 mm of total length, the occurrence of colour abnormality on ocular and blind sides and bone deformity were assessed. Vitamin A was not effective in preventing the colour abnormality on the blind side. However, fish fed experimental diet containing 20, 000 IU vitamin D/100g diet showed a higher rate of colour abnormality on the blind side compared with the commercial diet X which contained 6, 440 IU vitamin D/100g diet. Furthermore, the rate of normal blind side in the fish fed commercial diet Y containing trace amount of vitamin D was higher than that in the fish fed experimental diets. Although there was no expansion of black spot on the blind side during the experiment when fish were fed the commercial diet Y, the occurrence of bone deformity was high in the fish fed commercial diet Y. These results suggest that the balance of vitamins A and D or other basal ingredients is necessary to avert abnormal bone formation in Japanese flounder.View full abstractDownload PDF (1063K) -
Hidemasa KAWAKAMI, Nobuyuki SHINOHARA, Masahiro SAKAI, Hideki KIHARA, ...1998 Volume 46 Issue 2 Pages 287-292
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe effectiveness of the LPS-CKC vaccine against psudotuberculosis was examined in yellowtail, Seriola quinqueradiata. The LPS-CKC vaccine compared with LPS or CKC vaccine provided excellent protection against an artificial challenge. The phagocytic activities and phagocytic index of blood and kidney leucocytes in fish vaccinated with LPS-CKC vaccine increased significantly compared to leucocytes from control fish. The production of superoxide anion of kidney leucocytes also increased in LPS-CKC vaccinated fish groups.View full abstractDownload PDF (777K) -
Daisuke TANAKA, Shinpei WADA, Kishio HATAI1998 Volume 46 Issue 2 Pages 293-299
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESS“Tenpuku disease”is an idiopathic disease characterized by an unusual swimming style, which occurs in goldfish with rounded body shapes after sudden declines in water temperature and/or during the winter time. The present study describes the results of gross, radiological and anatomical examinations of the diseased fish in comparison with healthy ones. This study revealed that the diseased fish showed a variety of unbalanced swimming styles, and also possessed higher swimming bladder angles and larger swim bladder cranial chambers than those in the healthy fish. In addition, lateral displacement of the swim bladder in the body cavity was observed in the diseased fish which displayed lateral turning in the water column. However, these factors were thought insufficient to explain the pathogenesis of the abnormal swimming styles found in the diseased fish. This paper is the first scientific description of this disease.View full abstractDownload PDF (5658K) -
Haruo SUGITA, Kae KAMATA, Hiroyuki OHTA, Yoshiaki DEGUCHI1998 Volume 46 Issue 2 Pages 301-302
Published: June 20, 1998
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSA total of 304 aeromonads were isolated from fish intestines, water and sediments of the Hikiji River, and examined for the protease-producing ability for each isolate. A. hydrophila and A. jandaei isolates were the first and second highest groups in the mean activity. Inhibitory effects of PMSF and OPA were found in 74 and 81% of all Aeromonas isolates, respectively. These results showed that different Aeromonas species produced different types of proteases.View full abstractDownload PDF (408K)
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