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Volume 53, Issue 4
Displaying 1-17 of 17 articles from this issue
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Katsutoshi KAWABE2005 Volume 53 Issue 4 Pages 333-342
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSEmbryonic development of the blacktip grouper, Epinephelus fasciatus, eggs and the effect of water temperature on their developmental speed, time required from spawning to hatching, and hatching rate were studied. The eggs were pelagic and spherical in shape, measuring 0.74-0.84 mm in diameter, with a single oil globule and a narrow perivitelline space. No pigmentation was discernible in the embryos. Their developmental patterns were similar to those of many other Epinephelus species. Newly-hatched larvae measured 1.67-1.71 mm in total length with 28 (12+16) myotomes and an oil globule in the posterior part of the yolk. High viable hatching rates were obtained at a range of temperatures from around the spawning temperatures and higher. The time between spawning and each developmental stage, including hatching, decreased exponentially with increasing temperature. The relationship between incubation temperature and the time to reach any developmental stage shows an inflection point at 27°C. The temperature characteristics μ and α as well as the Q10 values were higher at temperatures between 18 and 26°C than those at temperatures between 28 and 32°C.View full abstractDownload PDF (1604K) -
Masahiro NAKAGAWA, Hiroyuki OKOUCHI2005 Volume 53 Issue 4 Pages 343-348
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSBlack rockfish is viviparous and one of the important target fish species for aquaculture and stock enhancement in Japan and Korea. Because size differences in black rockfish larvae lead to increased cannibalism, preparation of a sufficient number of larvae with the same or similar daily age is necessary for efficient aquaculture. We developed a method to concentrate the parturition period of female broodstock by examining the developmental stage of embryos using cannulation and selecting females, which are predicted to have similar parturition dates. We set up two groups examined over a 3-year period: one for selected broodstock with cannulation of embryos and the other as unselected control groups. The parturition period of the selected group was significantly shorter than that of the control group and greater numbers of larvae with the same parturition date were obtained in the selected group over the 3 years of experiments. The differences between the predicted dates and the actual dates of parturition were 1-3 days for the day parturition began and 0-2 days for the day parturition ceased. These results indicate that selecting broodstock female on the basis of the inspection of the embryonic developmental stage using cannulation will enable us to obtain newly released larvae for systematic and efficient aquaculture.View full abstractDownload PDF (887K) -
Tomoyuki NAKAMURA, Norio ODA2005 Volume 53 Issue 4 Pages 349-354
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe object of this study was to make clear the daily rhythms of ascending activity and relationship between rainfall and ascending activity of fish in paddy field ditch. The study was conducted in the Ogawa ditch of the Naka River system, Tochigi Prefecture, central Japan from April to October in 1999 and from April to September in 2000. A diurnal ascending activity and a nocturnal ascending activity was observed for adults of Zacco platypus and Pseudobagrus tokiensis in each spawning period, respectively. Diurnal ascending activities were also observed for juveniles of Z. temminckii and Tribolodon hakonensis and adults of Gnathopogon elongates elongatus, Acheilognathus melanogaster, Misgurnus anguillicaudatus and Cobitis biwae in their non-spawning periods, respectively. The number of fish ascending was larger on rainy days than on non-rainy days in both spawning and non-spawning periods for adults of M. anguillicaudatus and in the spawning period for adult of P. tokiensis. In contrast, there was no significant relationship between rainfall and ascending activity for adults of G. e. elongatus in both spawning and non-spawning periods and for juveniles of Z. temminckii and T. hakonensis in their non-spawning periods.View full abstractDownload PDF (854K) -
Takanari KIRIYAMA, Akihiko FUJII, Yuji FUJITA2005 Volume 53 Issue 4 Pages 355-365
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSPoor growth phenomenon of Sargassum fusifoyme thought to be caused by fish feeding has been occurred recently along the coastal region of Nagasaki Prefecture. We conducted feeding experiments on S. fusiforme in outdoor tanks with six herbivorous fish species that occur in the study area. Three species, Siganus fuscescens, Kyphosus bigibbus, and Calotomus japonicus fed on S. fusiforme in significantly and left characteristic bite marks on the thalli: bite marks are regular and smaller serrated scars by S. fuscescens, slightly irregular and wider serrated scars by K. bigibbus, and irregular rugged scars by C. japonicus. Of these three species, S. fuscescens fed 15 to 20 times more on S. fusifoyme than the two other species and showed feeding selectivity. On S. fusifoyme collected from the site where poor growth typically occurs, 39 to 67% of the specimens had characteristic bite marks made by S. fuscescens. This suggests that the species that cause poor growth through feeding can be identified from observations of the bite marks, and S. fuscescens is probably the most influential species at this site.View full abstractDownload PDF (9790K) -
Apostolos MIHELAKAKIS, Christos TSOLKAS, Takao YOSHIMATSU2005 Volume 53 Issue 4 Pages 367-376
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSLarval development, growth and morphological changes of laboratory-reared common dentex, Dentex dentex, were described from a series of preserved specimens. Larvae were reared intensively in 2 kl tank under a constant photoperiod (18L : 6D), and fed initially on rotifers, followed by Artemia nauplii and weaned onto an artificial diet. Water temperature ranged between 16.0 and 21.2°C with an average of 19.3±1.6°C. Newly hatched yolk-sac larvae had a mean total length (TL) of 2.80-0.13 mm. Larvae completed yolk absorption by day 9 after hatching at 3.72±0.21 mm TL with a mean water temperature of 16.5°C at 167°D. Feeding began on day 4 and 5. Absorption of the oil globule was completed by day 11 at 206°D. Transformation from larval to juvenile stage occurred at 9.00-7.42 mm TL in days between 27 and 34 after hatching (524-673°D), respectively. The equation Y=0.0002X3-0.0065X2+0.1432X+3.0000 (γ=0.967, n=1070), where Y is TL in mm and X is days after hatching represents larval growth under the applied rearing conditions. Larval allometric characteristics were also studied and some marked morphometrical changes corresponding to the morphological changes in early developmental stage of D. dentex were observed.View full abstractDownload PDF (1578K) -
Hisatoshi IKEDA, Takashi MATSUISHI, Yasuji KANNO2005 Volume 53 Issue 4 Pages 377-382
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSFour methods of heritability estimation of threshold trait, binomial method, arcsine transformation method, probit transformation method and Dempster and Lerner method were compared for the accuracy of estimation. We generated the threshold trait values using simulation assumed nested breeding system. Then we estimated the heritability from nested ANOVA by using each of four methods. Dempster and Lerner method was found to be the best among the four methods in terms of the accuracy and robustness. Binomial and arcsine transformation methods appeared to show the same output, which significantly resulted in underestimation. It was considered that the underestimation was lead from the dependence of mean and variance in the traits value transformed by the methods.View full abstractDownload PDF (830K) -
Syozo YAMAMOTO, Hiroyuki SUGINO, Kenji CYURIKI, Nobufumi MASUNARI2005 Volume 53 Issue 4 Pages 383-389
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe ontogenetic onset and feeding activity in the dark were investigated for marbled sole Pleuronectes yokohamae reared in a laboratory during 5 to 60 days old after hatching. The numbers of food organisms (rotifers Brachionus sp. and nauplii of Artemia sp.) in the gut were counted as the index of feeding activity. Larvae < 25 days old could not feed in the dark. However, ingestion of food organisms was first observed in larvae that were 31 days old and over 8.0 mm in total length (TL) . The filling rate in the dark increased with the growth of larvae > 9.0 mm TL, but mean number of food organisms ingested in the dark was fewer than that in the light. Therefore, it appeared that their feeding activity in the dark was inferior to that in the light. These results indicate that the larvae and juveniles larger than 8.0 mm TL of P. yokohamae feed mainly during the daytime, and feeding activity in the dark at night is not always enough for capturing of food organisms.View full abstractDownload PDF (1074K) -
Ken-ichi YAMAMOTO, Takeshi HANDA, Masanori GOTO, Shiro ITO, Itsuro KAW ...2005 Volume 53 Issue 4 Pages 391-396
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSTwo experiments were conducted to elucidate the effect of two chemicals, ammonium nitrate and organic acid compound, on ventilation of the pen shell Atrina (Servatrina) lischkeana. These chemicals are usually used during layer (Porphyra) culture as a fertilizer or for the treatment to prevent the injury with the attached diatom at the farm, which is the natural habitat of the pen shell. In the first experiment, the ventilation was continuously measured with a newly devised apparatus by exposing the pen shell to running seawater containing these chemicals at concentrations that were increased every 1 hour for 8 to 12 hours. In the second experiment, the survival ratio was observed every 12 hours by exposing animals to seawater containing these chemicals in a tank for 72 hours at the concentration that had affected ventilation in the first experiment. With regards to ammonium nitrate, the ventilation pattern was affected at 79-107 ppm and the survival ratio after exposure to 100 ppm seawater for 48 and 72 hours were 80 and 0%, respectively. For the organic acid compound, the change of ventilation pattern appeared at a concentration higher than 30 ppm (pH 7.6) and the pattern was significantly affected at higher than 100 ppm (pH 6.6), but the survival ratio remained 100% after 72 hours at 100 ppm. These findings were discussed in relation to the actual effect of these chemicals on the pen shell in the natural habitat.View full abstractDownload PDF (799K) -
Tatsuya YURIMOTO, Yukio MAENO, Shigeaki MATSUI, Naoki YOSHIOKA, Yasuno ...2005 Volume 53 Issue 4 Pages 397-404
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSThe objective of this study was to clarify the relationship between sexual maturation and the glycogen contents in the adductor muscle, mantle, and midgut gland of the pen shell Atrina pectinata in Ariake Bay from February 2000 to February 2001. The annual changes of the index of viscera (IOV) [ (viscera: g) ×10, 000/ (shell length: cm) 3] in males were similar to those in females, showing an increase from February, a maximum level in July, and a rapidly decrease in August. Histological observations of the gonads of males and females revealed that the pen shell were mature from July to August, with peak spawning in August, as indicated by a significant decrease in JOY. Periodic acid-Schiff (PAS) positive staining was observed in the adductor muscle and muscular tissue of the mantle. PAS-negative staining was observed in connective tissue of the mantle and the midgut gland. The glycogen content of the adductor muscle was higher throughout the year than the glycogen contents of the mantle and the midgut gland. The glycogen contents in the adductor muscles showed maximum values in April and then gradually decreased during the spawning period. These results showed that the annual changes in the glycogen content in the adductor muscle are closely related to the development of the gonads, suggesting that the glycogen content is a useful parameter for characterizing the physiological condition of the pen shell.View full abstractDownload PDF (12996K) -
Hitoshi IMAIZUMI, Takurou HOTTA, Hiromi OHTA2005 Volume 53 Issue 4 Pages 405-411
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSSince the kelp grouper is the protogynous fish, it is difficult to obtain mature males. We examined a method for the cryopreservation of the sperm for the development of systematic production of the seedlings of the fish. Five aliquots of DMSO (cryoprotectant) plus 93 aliquots of 300 mM glucose (extender) constituted the most suitable milt diluent for cryopreservation compared with other concentrations of DMSO or Glycerol as a cryoprotectant and artificial seminal plasma or 300 mM sucrose as an extender. Milt was diluted at 50 times with the diluent and dispensed into 500μl straws. The straws were suspended at various heights (from 1 to 7 cm) above the liquid surface of nitrogen (LN) for 5 min then immersed into the LN. Straws suspended at 3 cm (the cooling rate was - 32.5°C /min, and the temperature reached was - 144°C ) contained spermatozoa with the highest post-thaw motility. With 20μl of post-thaw milt added to 10 g of eggs, fertility exceeded 80%, and hatchability was equivalent to that of fresh milt. These results indicate that cryopreserved sperm of the kelp grouper is adaptable for the artificial fertilization on a commercial scale.View full abstractDownload PDF (1240K) -
Aki NAMBA, Hitomi HIROSE2005 Volume 53 Issue 4 Pages 413-417
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSSome strains of the genus Aeromonas are known as primary pathogens in many fish species, and its adhesion to mucosal surface has been recognized as the initial stage of infection. This study was undertaken to develop a simple microtiter plate assay method for measuring mucosal adhesion of A. hydrophila and A. veronii strains using a water-soluble tetrazolium salt (WST-1) . Mucus extract sample (MES) which was prepared from intestinal tract of carp, was placed into wells of a 96 well-microtiter plate and incubated overnight at 4°C. Then, each well was washed three times with PBS to remove the excess MES. After then, bacterial suspensions were added into wells and the plate was incubated for 1 h at 25°C. The wells were washed three times with PBS, incubated with WST-1 for 1 h at 25°C, and measured at OD 450 nm. In this study, different adhesive capabilities were observed among the A. veronii strains. Also, results of the WST-1 assay were comparable to those of the direct count method using Giemsa staining. These results indicate that the WST-1 assay is efficient for study of mucosal adhesion of bacteria such as Aeromonas group.View full abstractDownload PDF (746K) -
Takanari KIRIYAMA, Akihiko FUJII, Yuji FUJITA2005 Volume 53 Issue 4 Pages 419-423
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSAt 12 sites where the poor growth of Sargassum fusiforme was thought to be caused by fish feeding, we estimated the species causing by observing bite marks left on the thalli in November 2004. At these sites, the poor growth phenomenon prevailed and 82 to 100% of the specimens sampled at different sites had cut marks on the distal portions of the thalli; these cuts apparently caused the poor growth phenomenon. Of the specimens with cut marks, 49 to 83% had bite marks. These results strongly suggest that the thalli of S. fusiforme were cut off by fish feeding and that fish feeding is the cause of the poor growth. Characteristic bite marks left on the thalli showed that the species causing were Siganus fuscescens and Kyphosus bigibbus. Fish feeding was also observed on many algal species at the study sites, which ranged from the intertidal to the upper subtidal zone, and had a wide influence on algal growth and density.View full abstractDownload PDF (721K) -
Toshio DOI2005 Volume 53 Issue 4 Pages 425-431
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSMorphological and histological development of the digestive system and changes in digestive enzyme activity were investigated in larvae and juveniles of mandarinfish Siniperca chuatsi reared in an aquarium. Yolk sac larvae (ca. 5.5 mm TL) just before first feeding have a differentiated, functional larval-type digestive system with a large mouth, jaw teeth, pharyngeal teeth and gastric blind sac and they showed activities of both a trypsin-like enzyme and at a relatively low level of a pepsin-like enzyme. Preflexion larvae (ca. 7-8 mm TL) preyed on fish larvae using the largely expandable blind sac. Later-phase flexion larvae (ca. 10 mm TL) showed higher pepsin-like enzyme activity than trypsin-like enzyme associated with the appearance of gastric glands. Postflexion larvae (ca. 12 mm TL) established the adult-type digestive system having pyloric caeca. Metamorphosed juveniles ( > ca. 20 mm) showed increased gastric glands and pyloric caecal lobules in number, and the mouth and gut in size, and digestive enzyme activities. Early appearance of piscivory of larval mandainfish may be supported by the quantitative development of the oral cavity and gastric blind sac which mainly occurred during the early phase of the larval period (< ca. 10 mm TL), and its acceleration could be done by both the continued quantitative developments and functional development of the adult-type digestive system after the mid phase of the larval period (> ca. 12 mm TL) .View full abstractDownload PDF (6563K) -
Hideshi YAGI, Satoru MATSUOKA, Kenji YAMAMOTO, Masashi JINNAI, Hidetsu ...2005 Volume 53 Issue 4 Pages 433-438
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSA 60-day feeding trial was conducted in a running sea water system to determine the appropriate protein and energy levels in the practical diet for spotted halibut Verasper variegatus (initial weight: 50.0 g) . Nine diets of three digestible protein (DP) levels (41, 46 and 56%), each with three digestible energy (DE) levels (360, 400 and 440 kcal/100 g) resulting in DP/DE ratios ranging from 98 to 150 mg/kcal, were fed to 20 fish (per 200-l tank) in duplicate. Weight gain tended to improve with increasing dietary DP level and decreasing dietary DE level, reaching a maximum in the diet (56.7% DP and 379 kcalDE/100 g) containing a DE level of 360 kcal/100 g at a DP level of 56%. Feed efficiency, protein efficiency ratio, energy efficiency and nutrient retention reflected growth response. Hematological characteristics were not affected by dietary DP and DE levels, while serum protein, triglyceride and cholesterol concentrations decreased with increasing dietary DE level at a DP level of 41%, and body fat content increased with increasing dietary DE level at DP levels of 46% and 56%. These results indicate that an increase in dietary DE level has no protein-sparing effect and that a diet with 56.7% DP and 379 kcalDE/100 g, corresponding to a DP/DE ratio of 150 mg/kcal, is optimal for growth, feed conversion and body composition of this fish.View full abstractDownload PDF (961K) -
Tatsuo HAMANO, Keiko IDEGUCHI, Kazuyoshi NAKATA2005 Volume 53 Issue 4 Pages 439-446
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSTo clarify the early ecology of amphidromous freshwater shrimps, larval drift in the freshwater area, larval distribution near the mouth of the river, and juvenile recruitment at the uppermost part of the tidal river area were studied in the Nishida River, western Japan. Juvenile recruitment was investigated by using artificial weed as settlement sites. In the river, zoeae of four shrimp species were collected within a short period after sunset, and all zoeae were in the first zoeal stage. About six million zoeae were estimated to pass downstream into the sea in 1998, but few zoeae were captured in the sea near the mouth of the river. Juveniles of three shrimp species, which have not previously been sampled in the river, were collected at the upper end of estuary. These results suggest that amphidromous freshwater shrimps widely disperse through the open sea and some juveniles migrate to other far rivers.View full abstractDownload PDF (1230K) -
Ken-ichi YAMAMOTO, Takeshi HANDA, Akira NISHIOKA2005 Volume 53 Issue 4 Pages 447-453
Published: December 20, 2005
Released on J-STAGE: December 10, 2010
JOURNAL FREE ACCESSTo infer the cause of mortality at the so-called “withering on stalk”of the pen shell, Atrina (Servatrina) lischkeana, an experiment was performed recording the ventilation volume (Vg) continuously using an abnormal pen shell which had greatly opened the body from the sand (standing individual) . The soft part of the pen shell was observed macroscopically. Standing individual had more than 30% of gills damaged. Vg decreased with increases in the degree of gill damage. Vg were 577 ml/min/kg in normal individual and 38 ml/min/kg in standing individual with 90-95% gill damage under normoxic condition. Although Vg increased under hypoxic condition, the ratio of increase decreased with increasing degrees of gill damage: 5.2 times normoxic Vg in the normal individual and 1.1 times in standing individuals with 90-95% damaged gills. From the results, when the gills are damaged more than 30%, the pen shell should project most of the body from the sea bed in order to reduce the resistance of inflowing water into the mantle cavity by widely opening the inhalant.View full abstractDownload PDF (10212K) -
2005 Volume 53 Issue 4 Pages 455-480
Published: December 20, 2005
Released on J-STAGE: March 09, 2010
JOURNAL FREE ACCESSDownload PDF (4441K)
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