All issues
Volume 65 (1999)
- Issue 6 Pages 991-
- Issue 5 Pages 797-
- Issue 4 Pages 613-
- Issue 3 Pages 373-
- Issue 2 Pages 167-
- Issue 1 Pages 3-
Volume 65, Issue 6
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Martasuganda Sulaeman, Yoshiko Ogura, Tatsuro Matsuoka, Gunzo Kawamura1999 Volume 65 Issue 6 Pages 991-997
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSTwo series of glass-tank experiments with blinded fish were conducted to investigate the existence of a ζ-point (a body section over which external stimulation alters forward and back ward motions of fish) against tactile stimulation and its effect in determining the direction of swimming upon contact with a net webbing. Cyprinus carpio, Salmo mykiss, Tilapia mossambica and Lepomis macrochirus were tested. Longitudinally random positions over the bodies of these fish were stimulated using thin sticks and they moved either forward or backward according to the location of the stimulated positions. Cyprinus carpio which encountered net webbing expanded in a tank proceeded into a mesh at different ratios under the conditions of three mesh sizes and three hang-in ratios. Geometrical analysis of contact of a netting twine and a fish body section indicated that the probability of proceeding into an encountered mesh increases with mesh size and is modally maximised at a certain hang-in ratio. It was concluded that, (1) a tactile ζ-point, ζt exists at a body section which is unique to each species, and (2) the probability for fish to proceed into a mesh of gillnet is affected by the position of ζt, body form and size, mesh size and hang-in ratio.View full abstractDownload PDF (769K) -
Toshio Takeuchi, Nobukazu Satoh, Sachio Sekiya, Tomohito Shimizu, Take ...1999 Volume 65 Issue 6 Pages 998-1004
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSThis experiment was conducted to investigate the effectiveness of two n-3 highly unsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), for larval swimming crab Portunus trituberculatus. Two experiments were carried out in 1l beakers with duplicate lots, each holding 30 larvae. Starting with the larval stage zoea 3, and though the megalopa stage, they were fed Artemia containing different amounts of EPA and/or DHA prepared using emulsifed oils (EPA ethyl ester, DHA ethyl ester, and DHA38G). During the feeding experiments, the molting rate and the inter-molt period in days to reach each stage were measured. It was found that EPA and DHA had different roles in larval development. EPA was effective in maintaining the survival rates for larvae, while DHA accelerated the developmental period and improved the growth of carapace. The highest molting rate and largest carapace width at the first crab were observed when the larvae were fed Artemia enriched with DHA 38G from the zoea 3 stage. Larvae fed unenriched Artemia had low molting rates and the smallest carapace width. These results suggest that it is important to feed the swimming crab with Artemia containing both EPA and DHA from the zoea 3 stage to avert the high rate of cannibalism among them during mass seed production.View full abstractDownload PDF (807K) -
Tomoki Ohnaka, Hiroyuki Sasaki, Kensho Nagai, Kenichi Numachi1999 Volume 65 Issue 6 Pages 1005-1009
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSWe analyzed restriction fragment length polymorphisms (RFLPs) at the D-loop region of mitochondrial DNA (mtDNA) in endangered cyprinid subspecies Pseudorasbora pumila subsp. sensu Nakamura (1963). All the six population samples consisted of three wild populations and three artificial breeding populations from Aichi and Gifu Prefectures. The examination showed marked monomorphism and three genotypes were distributed along with each geographical locations. As a result, some possibility was shown that the parents of artificially breeding populations had been monomorphic when they were collected. We thought experimental tests should be done for the conservation of this subspecies, stocking three genotypes under various conditions and investigating their adaptability.View full abstractDownload PDF (692K) -
Tsutomu Sadakata1999 Volume 65 Issue 6 Pages 1010-1022
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSThe growth pattern of the Northern Shrimp was made clear by tracing size composition of the dominant year class and spawning interval, and the following results were obtained. Most of the northern shrimp change sexes from male to female at 5 years old. In the female stage they spawn eggs every other year and make the first hatch of the larvae at 7 years old. The number of spawning times was estimated to be more than three. So the life span of the Northern Shrimp was estimated to be longer than 11 years. The growth rate is low, and the life span is long as compared with those obtained so far. Growth formula was determined as lt=34.15[1-exp{-0.252(t+0.016)}], where lt represents carapace length in mm at age t in years. The Northern Shrimp of the Sea of Japan is inhabited in the most southern region. However the growth rate of the species is low as compared with other areas. This is due to the fact that the living water temperature is very cold.View full abstractDownload PDF (1243K) -
Koji Takeno, Yuichi Hamanaka, Izumi Kinoshita, Toshiaki Miyajima1999 Volume 65 Issue 6 Pages 1023-1029
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSSamples of the Japanese flounder Paralichthys olivaceus, 672 females, 550 males, were caught from coastal fishing grounds in western Wakasa Bay from 1992 to 1998. Based on the four stages of maturity for females and the three stages for males and/or the gonadosomatic index, flounder of both sexes were classified into each stage by the year class. For females, 5% of two year old and more than 75% of the three year olds and older fish were mature. For males, less than 5% of one year old fish, 50% of two year old fish and more than 80% of the three year olds and olds and older fish were mature. The minimum size in the mature stage were ca. 43cm TL for females and ca. 32cm TL for males, that is, more younger males than females reached the mature stage. Flounder in the mature stage were found from late February to early June. Gonadosomatic indexes of females generally increased after early February and peaked in early April, when the percentage of occurrences of mature females was 100%. 20% of females showed spent gonads from early May and more than 80% showed spent gonads in early June. From these findings, it was implied that the spawning period of the japanese flounder in western Wakasa Bay was from late February to early June with a peak during April and May.View full abstractDownload PDF (890K) -
Naoshi Makino, Masashi Uchiyama, Shigeyuki Iwanami, Tadatugu Tohyama1999 Volume 65 Issue 6 Pages 1030-1041
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSIt is very important to develop efficient and stable techniques for obtaining fertilized eggs with good quality as well as sufficient quantity, particularly for difficult species as Japanese Sea Bass. Effects of a single hormone or combined hormone treatments on induction of oocyte maturation and ovulation were examined in wild Japanese Sea Bass which were collected by longlines near the coast of Kujukuri in Chiba Prefecture during spawning season in 1989 and 1990. The present data were evaluated by comparison with previous data obtained from 1982 through 1988. HCG (human chorionic gonadotropin) from 1982-1990, SP (silver carp pituitary extract) in 1989 and CP (chum salmon pituitary extract) in 1990 were used in the respective experiments. HCG-SP group produced viable eggs by artificial insemination. Spontaneous spawning in tanks was induced by HCG-SP and SP treatments, but the number of eggs was evidently larger in HCG-SP group. HCG-CP treatment was more effective than HCG-SP treatment in 1989. The number of floating viable eggs and hatched larvae induced by the combined hormone (HCG and pituitary extracts) treatment appeared to be greater than those obtained by a single hormone treatment conducted from 1982 through 1988. These results suggest that the combined hormone treatment is effective in inducing ovulation for Japanese Sea Bass.View full abstractDownload PDF (1316K) -
Naoshi Makino, Shinichi Kaneko, Eiji Kojima, Tadatugu Tohyama1999 Volume 65 Issue 6 Pages 1042-1053
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSSequential changes in body weight and oocyte development after injection of gonadotropic hormones were examined for wild Japanese Sea Bass collected during spawning season in 1991 and 1992. Just before hormonal treatment oocyte samples were sucked out with a catheter and maturational stage of oocytes was examined by microscopic and histological observations. Twenty mature females (3.7 to 5.9kg) in 1991 and 13 females (2.3 to 7.2kg) in 1992 spawning seasons, collected by longlines near the coast of Kujukuri in Chiba Prefecture, were used. They were injected with both human chorionic gonadotropin (HCG) and chum salmon pituitary extract (CP). Based on changes in the fish body weight and maturational stage of oocytes, artificial inseminations were conducted. The period from injection to ovulation varied depending on maturational stage of oocyte at the time of injection : 3-4 days needed from oocytes at the secondary yolk globule stage (oocyte diameter ranged 560-700μm), 2-3 days from oocytes at the tertiary yolk globule stage (690-800μm), 2 days from oocytes at the migratory nucleus stage (800-880μm), 1 day from prematuration and mature stages (890-1080μm and 1100-1190μm). The present results combined with previous results suggest that time at which optimum egg quality is achieved is within one day after ovulation and optimum hormonal doses/kg fish are ca. 500IU of HCG and ca. 20mg of CP.View full abstractDownload PDF (1489K) -
Yoshiaki Harada1999 Volume 65 Issue 6 Pages 1054-1061
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSSeventy specimens of the cultured pufferfish Takifugu pseudommus imported from China to Fukuoka Airport between 1994 to 1997 were studied. The external and osteological characters were examined. The colour of the anal fin of the specimens was almost the same as that of T. rubripes and T. pseudommus. Although no irregular black spots similar to T. rubripes were observed on the body in accord with T. pseudommus, in some specimens (ca. 26%), one or a few black spots behind the ocellated humeral blotch were observed in concordance with the specimen ((59) 1099) collected by the author of the scientific name. According to the key to members of genus Takifugu, the specimen is identified as T. pseudommus. On the other hand, judging from the external appearance of the cranium and the degree of incurvation of the longitudinal ridge of the frontal, the specimens seem to be both or either T. pseudommus and T. chinensis. But, because the colour of the anal fin, cranial proportion, and number of abdominal vertebrae (8) were different from those of T. chinensis, the specimen was concluded to be T. pseudommus. In addition, the theory that both T. pseudommus and T. chinensis belong to one and the same species was proved to be incorrect. Furthermore, the pufferfish which had been taken for"Nameradamasi"in recent times in Japan is different from T. pseudommus.View full abstractDownload PDF (1100K) -
Manabu Hibino, Hiroshi Ueda, Masaru Tanaka1999 Volume 65 Issue 6 Pages 1062-1068
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSThe early life history of the Japanese temperate bass Lateolabrax japonicus in the Chikugo River estuary is characterized by a habitat shift toward lower salinity environments with larval growth. To clarify the ecological background of this ascending migration, feeding habits of the bass and distribution of prey copepods were investigated in March and April of 1997. dominant copepods present in the environment and those preyed on by fish varied greatly with the salinity of the water. The bass preyed exclusively on cyclopoid copepods (mainly Cyclops vicinus) in the fresh-water region, and on a brackish-water calanoid Sinocalanus sinensis in the region of low salinities (0.1 to ca. 15). In the areas of salinities higher than 13.8, it preyed on common coastal copepods (Oithona davisae, Paracalanus parvus s.l. etc.). Surveys on zooplankton distribution revealed that S. sinensis was extremely abundant in the low salinity region, while the copepod density was much lower in high salinity and fresh-water regions, in spring. We concluded that the utilization of S. sinensis is one of the ecological key factors directly involved in the growth and survival of the Japanese temperate bass larvae and early juveniles which migrate toward the low salinity zone of the Chikugo River estuary.View full abstractDownload PDF (842K) -
Masahiro Furuse, Kenkichi Fukurotani1999 Volume 65 Issue 6 Pages 1069-1077
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSFrequency response properties of L-type S-potential in the retina in situ of the Japanese flounder Paralichths olivaceus were examined by flicker light stimulus. Three light intensities for the flicker were used. At the lowest intensity, response amplitude of the S-potential decreased monotonically as flicker frequency became higher. At the higher intensities, however, the response amplitude had a sub-peak around 20-30Hz. We supposed that this phenomenon was some resonance caused by light adaptation of the retina as the light intensity of the flicker, therefore retinal mean illumination, increased. It is thought that S-potential can respond only to low frequencies. However, the obtained critical fusion frequency (CFF) in the experiments was 60Hz or more, indicating that S-potential is able to respond over 60 Hz in the retina in situ of the Japanese flounder.View full abstractDownload PDF (1068K) -
Yoshio Niiya1999 Volume 65 Issue 6 Pages 1078-1083
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSTagging and recapture experiments of Bullet Tuna were carried out in the eastern and central coastal waters of Japan from 1970 to 1994 for the investigation of it's migration pattern. A total of 12, 925 fish were tagged and released in the waters between the Kyushu coast and the Izu Islands. Main recaptures of 129 fish were reported off Kouchi. Recaptures of 61 fish were obtained from the Kyushu coast, the Kii Channel, Kumanonada, Suruga Bay, Tokyo Bay, the Boso Peninsula and Kasimanada. Bullet Tuna stay south of Shionomisaki from the winter to the spring. They migrate north of the Boso Peninsula with the rise of the water temperature in the summer. They migrate south of Shionomisaki with the lowering of the water temperature in the fall. The migration estimated from the tagging experiments agreed with the report of the migration estimated from the change in fishery and the length frequency distribution.View full abstractDownload PDF (636K) -
Masaru Yamaki, Haruhei Satou, Kou Taniura, Katsutoshi Arai1999 Volume 65 Issue 6 Pages 1084-1089
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSInduction of tetraploid amago salmon was attempted by treating inseminated eggs with hydrostatic pressure shock (650kg/(cm)2, 6 min duration) in 1996 and 1997. Based on the apperance of four nucleoli in the epithelial cells of pectoral fins, putative tetraploids were selected among sixmonth-old juveniles developed from pressure-shocked eggs of both year classes. At the age of twenty three months, the surviving ten females of the 1996 year class were flow-cytometrically determined to be diploid by measuring DNA content of erythrocytes. However, both diploids and triploids were detected in the progeny, when one of these diploid females was crossed with normal diploid males. Other females gave no triploid progeny. Among eleven individuals examined in the one-yearold 1997 year class salmon, a diploid-tetraploid mosaic male was found, but the others were diploid. All the progeny examined were diploid, when the eggs of a normal diploid were fertilized by spermatozoa of this mosaic male. The present results suggest the possible production of tetraploid and other polyploid lines using diploid gametes of fish which developed from the chromosome manipulation to inhibit first cleavage for induction of tetraploids but were determined to be diploid in adult stage by cellular size and DNA content of somatic cells. Such chromosomally-manipulated fish are likely to be mosaics including tetraploid cells in their germ line, in spite of a large population of diploid cells in soma. The present results also demonstrate a different case in which the apparent diploid-tetraploid mosaic generated only haploid spermatozoa.View full abstractDownload PDF (833K) -
Koichi Kataura, Satomi Koseki, Hiroko Ogawa, Fumito Yamazaki, Yoshiaki ...1999 Volume 65 Issue 6 Pages 1090-1095
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSA study was made on the extraction of chlorophylls with ethanol from the dry brown seaweed Konbu, Laminaria japonica, and coloring under illumination with fluorescent light was investigated to improve the greenish color of the seasoning extractive from Konbu. The results obtained were as follows : (1) The chlorophylls in the brown seaweed were effectively extracted with two-times the weight of absolute ethanol relative to that of the crushed dry material. (2) There was a negative correlation between the average particle size of dry seaweed and the extractable amount of chlorophylls with ethanol. (3) When the chlorophylls in ethanol solution were illuminated under fluorescent light, a greenish color developed. This coloring is supposed to be caused by allomelization of chlorophyll molecules. (4) It is clear that when the chlorophyll extract treated by illumination is added to the seasoning extractive of Konbu, the greenish color can be enhanced.View full abstractDownload PDF (727K) -
Kunio Suetsuna, Hiroyuki Ukeda1999 Volume 65 Issue 6 Pages 1096-1099
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESSA peptidic fraction having active oxygen scavenging activity was separated from the peptic digest of sardine muscle by ion-exchange chromatography and gel filtration. Further separation by ODS HPLC afforded an active peptide; Leu-Gln-Pro-Gly-Gln-Gly-Gln-Gln. The IC50 value for superoxide scavenging activity was 465 μM as determined by the tetrazolium salt XTT method, while that for hydroxyl radical scavenging activity was 24.6μM as established by ESR.View full abstractDownload PDF (560K) -
Masahiro Furuse, Atsushi Okubo, Masashi Mikkaichi, Kenkichi Fukurotani1999 Volume 65 Issue 6 Pages 1100-1101
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESS -
Tadashi Sakai, Shinya Maetsu, Hisashi Murata, Masaharu Ugawa1999 Volume 65 Issue 6 Pages 1102-1103
Published: November 15, 1999
Released on J-STAGE: February 01, 2008
JOURNAL FREE ACCESS
- |<
- <
- 1
- >
- >|