Aquaculture Science
Online ISSN : 2185-0194
Print ISSN : 0371-4217
ISSN-L : 0371-4217
Volume 42, Issue 4
Displaying 1-19 of 19 articles from this issue
  • Kyung-nam HAN, Seiichi MATSUI, Masayuki FURUICHI, Chikara KITAJIMA
    1994 Volume 42 Issue 4 Pages 507-514
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    In order to clarify the optimum stocking density for seed production of the puffer fush, Takifugu rubripes, five series of rearing experiments from larva to young were carried out under different density conditions. The estimation of the optimum stocking density was based on growth, survival rate, and degree of loss of the caudal fin by cannibalism. The results obtained showed that the optimum stocking densities of larva (3.3-10.0 mm TL), early juvenile (10-40 mm TL), late juvenile (30-50mm TL) and young (50-75mm TL) were approximately 25000, 2800, 600 and 100 individ./m3, respectively.
    Download PDF (862K)
  • Seiji KOMATSU, Yutaka ISHIDA, Yukio KAWASHIMA, Hiroshi TOKUDA
    1994 Volume 42 Issue 4 Pages 515-520
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Experiments on photosynthetic CO2 fixation by E. prolifera were carried out outdoors in 500l FRP tanks with a surface area of 1 m2 each. When a cultivation tank containing sea water was aerated with CO2 gas (1lmin-1), the pH of the sea water decreased to 6.5 whereas the growth of this alga was stimulated as much as 1.5-1.7 times. Maximal CO2 fixation rate (12 g-C m-2 day-1), photosynthetic efficiency (4 %) and CO2 fixation efficiency (9 %) were induced through CO2 aeration at a rate of 74 g-C day -1. Photosynthetic CO2 fixation rate during outdoor cultivation of this alga was maximal under solar radiation of 10-15 MJ m-2 day-1. Based on these results, the annual CO2 fixation rate of this alga in the Shikoku district was estimated to be 2 kg-C m-2.
    Download PDF (614K)
  • Katsuhiro KISO
    1994 Volume 42 Issue 4 Pages 521-528
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Adult masu salmon were collected with set nets or purchased in fish markets near Oshika peninsula (the Pacific coast of northern Honshu) from 1983 to 1989. Their stomach contents were observed and the food composition was analyzed using 3 different indices (number, weight, frequency of occurrence of each kind of prey) . The Index of Relative Importance (IRI) was also used to compare the accuracy of the 3 indices. Results were analyzed in relation to the month of catch size classes of masu salmon. Sand lance, Ammodytes personatus, anchovy Eugraulis japonica, juvenile of Alaska pollack, Theragra chalcogramma, sardine, Sardinops melanostictus among others constituted the main food independently of season and size but masu salmon also preyed on large-sized plankton such as Themisto japonica and Euphausia japonica. Overall, sand lance was a major contributor to food in weight and occurrence between March and June whereas T. japonica was the major contributor to food in number in April and May. Large-sized masu salmon depended more heavily on fish as food than small-sized masu salmon. Furthermore, the size and composition of prey differed between adult and juvenile masu salmon. Adult masu salmon took 1-age sand lance, large-sized T. japonica, and E. japonica, and pelagic fish such as sardine. Juvenile masu salmon took 0-age sand lances, small-sized T. japonica, Thysanoessa longipes (Euphausiasia), and brackish water fishes such as ice goby, Leucopsarion petersi. These results indicate that masu salmon change habitat and food-size selectivity as they grow.
    Download PDF (922K)
  • Masanobu KISHIOKA, Yurimasa TERAO
    1994 Volume 42 Issue 4 Pages 529-533
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Seed production of ark shell, Scapharca broughtonii in Japan is traditionally carried out in high density-, small-sized tanks (1 m3) . This system is labor-intensive and requires expensive equipments ; these two factors constitute constraints to mass seed production. In this experiments the feasibility of a labor-saving protocol using a 100 m3 tank for mass seed production was examined. Survival rates during seed production using the new and traditional protocols were 33 and 23-31 %, respectively. Average shell lengths with the new and traditional protocols were 1, 400 and 775 μm respectively. These results suggest the feasibility and possible superiolity of mass seed production of S. broughtonii in large-sized tanks.
    Download PDF (528K)
  • Nobuaki WATARI, Hiroyuki INOUE, Hachiro HIRATA
    1994 Volume 42 Issue 4 Pages 535-539
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Acute toxicity of the organophosphate “MEP” [O, O-dimethyl O- (3-methyl-4-nitrophenyl) phosphorothioate] and the carbamate “NAC” [1-naphtyl-N-methylcarbamate] to larvae of red sea bream, Pagrus major and Japanese flounder, Paralichthys olivaceus was determined by static water bioassay. Red sea bream larvae (5-47 days after hatch) were arbitrarily divided into 5 developmental stages. Japanese flounder larvae (3-60 days after hatch) were divided into 8 developmental stages. Susceptibility of each stage to the above pesticides was investigated. In all stages of red sea bream larvae, the values of 24hr LC50 were 1.2-1.7 ppm for MEP and 0.9-3.2 ppm for NAC. In all stages Japanese flounder larvae, the values of 24hr LC50 were 0.8-2.8 ppm for MEP and 0.9-3.2 ppm for NAC. In both species, susceptibility to the pesticides was unrelated to the developmental stage. Apparent neurotoxicity symptoms were induced in larvae exposed to MEP and NAC, such as loss of equilibrium, decrease in spontaneouse motor activity, change in body color to dark, and wild excitement.
    Download PDF (446K)
  • Akira KOMARU, Katsuhiko T. WADA
    1994 Volume 42 Issue 4 Pages 541-546
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Gametogenesis and growth of induced triploid pearl oyster, Pinctada fucata martensii were examined between one and two years of age in Gokasho Bay, Mie, Japan. Although the gametogenesis in triploids was impaired compared with that in diploids, triploids produced mature oocytes and sperm. Frequency of hermaphrodites among triploids at 12 and 24 months of age were 27 % and 20 %, respectively, while no hermaphrodites were observed among diploids.
    Shell height, shell width, and soft body wet weight of triploids at 21 and 26 months of age were significantly larger than those of diploids, while those of triploids at 12 months were smaller than those of diploids. These results suggest that better the growth of triploids may be related to their reduced reproductive activity.
    Download PDF (3732K)
  • Apostolos MIHELAKAKIS, Chikara KITAJIMA
    1994 Volume 42 Issue 4 Pages 547-552
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    The effects of reduced rations on the growth rate and the efficiency of food utilization of four-month-old silver sea bream Sparus sarba were examined, at ambient water temperature. The relationship between growth rate (g) and food intake (f) was expressed by the equation g=-0.3122+1.6006f-0.2384f2. The optimum ration was estimated to be 1.15 % wet body weight/day and it was equivalent to 41.4 % of the ration sufficient to satiate the fish in one continuous feeding. The maintenance requirement was calculated to be 0.201 % wet body weight/day. Gross conversion efficiency increased rapidly with increasing ration up to a maximum at the optimum ration, and declined at higher rations. Net conversion efficiency was highest at near maintenance ration and declined with increasing the ration size. The relationship between net conversion efficiency (En) and food intake (f) was expressed by the equation En=1.5505-0.2371f.
    Download PDF (574K)
  • Takeshi TOMA
    1994 Volume 42 Issue 4 Pages 553-561
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    This paper deals with the seasonal, topographical and geographical distribution of edible red alga Gloiopeltis complanata in the islands of Okinawa. Survey using a quadrat was carried out from 1990 to 1991. This species occurs in the northern and northeastern parts of Okinawa island and the vicinity islands such as Ikei, Ie, and Kume. It has been previously reported from the islands of Zamami and Tokasiki of the Kerama. This species has never been observed in the islands of Sakishima. Thus, it seems that the southern limit of the distribution of G. complanata is the island of Okinawa and its immediate vicinity (26° latitude north) . The habitat of this species is the spray zone in the lateral coral reef. It grows on the rocky substrata of phyllite and sandstone. These substrata are prefered because they have greater capacity to hold moisture than Ryukyu limestone. The maximum biomass reached 610 g/m2 in March when the maximum length was 2 cm. The germination starts in the beginning of November and the thalli alga disappear in the beginning of June.
    Download PDF (3229K)
  • Hiroyuki HATANAKA, Hideki UWAOKU, Toru YASUDA
    1994 Volume 42 Issue 4 Pages 563-566
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    This study investigated the effect of prey size and water temperature on the predation of juvenile sea cucumber, Stichopus japonicus, by sea star, Asterina pectinifera. Sea stars (average arm length 43.3 mm) ate an average of 1.8, 0.5, 0.1, and 0 sea cucumbers/day/predator when the average body lengths of the prey were respectively 15.9, 30.1, 40.0, and 54.6 mm. Likewise, sea stars (average arm length 46.2 mm) ate 0.9, 0.8, and 0.2 prey (average body length 29.2 mm) / day/predator when held at temperatures of 20, 15, and 10°C. It is concluded that the predation rate of sea cucumber by sea star decreases with increased prey size or lower water temperature.
    Download PDF (396K)
  • Yasuhide GOHYA, Soichiro NAKAMURA
    1994 Volume 42 Issue 4 Pages 567-570
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    The plate-MPN technique, a simplified system for calculating of viable bacteria that combines both the surface-plate method and the most probable number (MPN) method, has been successfully applied to the determination of numbers of proteolytic bacteria in natural water. The analysis of 13 fresh-water and 10 seawater samples revealed that the plate-MPN technique had same performance relative to the conventional method required the colony isolation and screening for the proteolytic activity test. Proteolytic bacteria of 1.3 × 10 - 7.9 × 103 were detected by the plate-MPN technique for 12h incubation, while the conventional method spends for 3 days until similar results could be drawn. A high correlative relationship (r=0.990, n=23) was observed between the counts by the plate-MPN technique and the conventional method, strongly indicating that the plate-MPN technique can be recommended method for rapid enumeration of proteolytic bacteria.
    Download PDF (1812K)
  • Masahiro KUDO, Kiyoki TSUTSUMI, Megumi MINAGAWA, Yuji AOKI, Shinji TSU ...
    1994 Volume 42 Issue 4 Pages 571-575
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    The spawning of Tectus pyiramis (Trochidae Gastropoda), caught off Hachijo Island, was induced using 35% hydrogen peroxide (0.01 ml/l) and heating. Hatching, formation of larval shell and settlement occurred 10, 20 and 50 h after fertilization, respectively. Metamorphosis to juvenile occured at 60 h after fertilization in 24.8-25.7°C. No larval hatching was observed in 16.8-17.5°C and the shell was incompletely formed in 20.0-21.4°C. Mean shell diameter was 16.3 mm at one year and 46.1 mm at two years after fertilization.
    Download PDF (3510K)
  • Nobuhiko AKIYAMA, Yoshimitsu OGASAWARA
    1994 Volume 42 Issue 4 Pages 577-584
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    The ice goby Leucopsarion petersi spawn at the lower reaches of rivers. Their reproductive behavior has not been properly observed due to their nesting habit under stones. We have reared parent fish in glass cases prepared for observation of nesting, mating, and brood-care behavior.
    Males were found building and protecting their nests under stones before attracting females. It was possible to watch and to take photographs of females entering, discharging eggs, and leaving the nests. Our observations also covered actions of males fanning water and brushing eggs in the nests, and newly hatched larvae leaving the nest.
    Polyethylene resin was poured into nests built in the Hatauchi River, so as to produce molds for measuring the size. Reliable molds were obtained for five nests in the observation field.
    The major and minor axes extended 50 to 128 mm and 12 to 112 mm, respectively. Height was found less variable than the above measures, ranging between 6.7 and 7.7 mm.
    Download PDF (5270K)
  • Katsutoshi ARAI, Atsushi TANAKA, Tadao KUSUNOKI, Ryo SUZUKI
    1994 Volume 42 Issue 4 Pages 585-591
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Allozyme expression in PGM, IDHP-2, LDH-1, and AAT-1 enzyme-coding loci was electrophoretically examined in hybrids between diploid and tetraploid races of spinous loath, Cobitis biwae and in intergeneric hybrids between the two races of spinous loath and common diploid loath, Misgurnus anguillicaudatus. The interracial hybrids showed asymmetrical expression of allelic products, indicative of heterozygous triploid genotypes including two alleles of the tetraploid race and one allele of the diploid race at the diagnostic loci. The intergeneric hybrids between tetraploid spinous loath and common diploid loath also exhibited similar electrophoretic phenotypes demonstrating triploid hybrid nature. On the other hand, those between diploid spinous loath and loath had phenotypes showing equal expression of two different alleles and were confirmed as diploid hybrids.
    Download PDF (4449K)
  • Osamu TOMINAGA, Masahiro MABUCHI, Hitoshi ISHIGURO
    1994 Volume 42 Issue 4 Pages 593-600
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    In order to examine movement and growth, 3, 623 wild and 5, 565 hatchery-reared Japanese flounder, Paralichthys olivaceus fry were tagged and released in the Sea of Japan off northern Hokkaido in June and August 1986, respectively. Wild flounder migrated north until September and then tended to move southward in winter. Most wild flounder recoveries were recorded in the release area and the area south of the release point one year or more after release. Similar results were obtained from the tagging experiment with reared flounder. The distribution of wild and reared flounder was thought to expand toward the south. The difference between growth of wild (0.61 mm/day) and reared flounder (0.44 mm/day) was significant. It is supposed that the poor degree of adaptation of reared flounder to the natural conditions was one of the factors affecting growth.
    Download PDF (917K)
  • Kotaro KIKUCHI, Takeshi FURUTA, Haruo HONDA
    1994 Volume 42 Issue 4 Pages 601-604
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Feeding experiments were conducted at 20 °C with diets containing 0, 20, 35, and 44 % of defatted soybean meal to examine the potential of soybean meal as a substitute for fish meal in the diet of Japanese flounder. Juvenile fish, about 3 g in initial body weight, were fed on each diet to satiation twice a day for 6 days a week for 8 weeks.
    The weight gain of fish fed on the diets containing soybean meal with amino acid supplement were similar to the control (0 % soybean meal diet), but fish fed on the diet without amino acid supplement gained less weight. The feed conversion efficiency and protein efficiency ratio tended to decrease slightly as the proportion of soybean meal in the diet increased. There was little difference in the proximate composition of the whole body together with the hematological and hematochemical parameters among the dietary groups tested.
    Download PDF (428K)
  • Masahiro KUDO, Katsutoshi ARAI, Takumi KIMOTO, Megumi MINAGAWA, Kazuo ...
    1994 Volume 42 Issue 4 Pages 605-613
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    Triploid abalones, Haliotis diversicolor diversicolor were produced by inhibiting the first or second polar body release with cold shock treatments. Yields of normal veliger larvae having complete larval shells were lower in triploidized groups than in the control, but no difference in survival rates of juveniles was observed between the two groups after six months. There was no differnce in shell-length and body weight between triploids and diploids. Proportion of muscle weight to that of whole body in triploids was higher than that in diploids, especially in females. All triploid females examined had normally maturing oocytes as observed in the diploids. However, the triploids also possessed a large number of small immature oocytes which were not seen in the diploids. Gonad indices of triploid males were similar to those of diploids, but spermatozoa were not detected in triploid males.
    Download PDF (1334K)
  • Shizuo KIMURA
    1994 Volume 42 Issue 4 Pages 615-618
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    We discovered 28 masu salmon, Oncorhynchus masou fry without parr marks and black spots among about 3, 000 in 1987. These fry were the progeny of wild fish from the Shokanbetu River in Hokkaido. In September 1988, we obtained about 8, 000 eggs (F1 generation) fertilized between 3 markless males and 15 normal females. They were reared until the adults as a pilot brood stock at Nanae Fish Culture Experimental Station, Faculty of Fisheries, Hokkaido University. We could find no fish with parr marks in the F1 generation. In 1991, an F2 generation was obtained from F1 parents. Among 44, 517 fry, 0.7 % were markless salmon. Using markless F2 generation adults, an F3 generation was obtained, seventy-six % of which had no parr marks or black spots. The markless salmon should be useful for release-recapture studies in the future.
    Download PDF (2411K)
  • Shuhei MATSUURA, Tsuyoshi NAITO, Mitsuto SHINCHO, Kenji YOSHIMURA, Mic ...
    1994 Volume 42 Issue 4 Pages 619-625
    Published: December 20, 1994
    Released on J-STAGE: March 09, 2010
    JOURNAL FREE ACCESS
    The process of gonadal sex differentiation in tiger puffer, Takifugu rubripeswas studied histologically. Paired primordial gonads were found under the mesonephric ducts of a fish 7 days after hatching. The gonads were sexually indifferent until 40 days. The first sign of ovarian differentiation was the formation of ovarian cavity, which was observed in the gonads of about a half of fishes at 45-50 days. The increase of oogonium in number became evident from 55-65 days, and the oocytes appeared at 86 days. The gonads which lacked the ovarian cavity were still sexually indifferent at 55-65 days. The germ cells began to increase at 55-65 days in the peripheral region of the gonads without ovarian cavity. This characteristic showed the testicular differentiation. The beginning of meiosis in the testis was not observed until 105 days. The sperm duct began to form in posterior region of the testis at 75 days. The features of intersexuality were not found in this study.
    Download PDF (7730K)
  • 1994 Volume 42 Issue 4 Pages 627-631
    Published: December 20, 1994
    Released on J-STAGE: December 10, 2010
    JOURNAL FREE ACCESS
    Download PDF (499K)
feedback
Top