All issues
Volume 59, Issue 3
Displaying 1-19 of 19 articles from this issue
- |<
- <
- 1
- >
- >|
Original Papers
-
Hoji Iwatani, Atsushi Onuki, Hiroaki Somiya2011 Volume 59 Issue 3 Pages 343-350
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSSound characteristics and the sonic muscle size in the catadromous fourspine sculpin Cottus kazika were examined in this study. The sound produced by this fish is composed of a series of 5 pulses lasting for 40-60 ms, with the peak frequency at approximately 100 Hz. The sonic muscle originates from the posteroventral surface of the cranium and inserts on the anterodorsal margin of the cleithrum. The sonic muscle somatic index (SMSI) value evidently indicated that the male sonic muscle was larger than that of the female throughout the year in both the wild and reared fish. In the wild fish, the mean SMSI value was 1.5 times larger in male’s than in female’s. Further, the mean SMSI value of the wild male fish significantly increased during the spawning season (December to March), suggesting reproductive phase related control of the sonic muscles size.View full abstractDownload PDF (293K) -
Takashi Uede, Yoshiaki Takahashi, Makoto Yamauchi2011 Volume 59 Issue 3 Pages 351-361
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSSurvey concerning crustacean community structure in Zostera japonica population was conducted by seine net once a month around neap low tide at daytime. There were 30 and 21 species in bare sandy shore and Z. japonica population, respectively. Numbers of individuals were 2,938 and 1,059, and wet weights were 162.2 and 9.3 g, respectively. At both sites, the communities declined in winter and reached their peak from summer to early autumn. Though most of the dominant species were common in both sites, the number of individuals, the body size and the time of appearance were different from each other. Especially, Penaeidae prawns and Palaemonidae shrimps dominated, but no species were all year round resident. Furthermore, most of the individuals of these species were immature and the body sizes in Z. japonica population were smaller than those in bare sandy shore. These results indicate that Z. japonica population provides a nursery habitat for these species on early stage of post-settlement life history. Furthermore, it is considered that the bare sandy shore in the vicinity of Z. japonica population functions as one of habitats for these species on subsequent stage of life history.View full abstractDownload PDF (797K) -
Hiroyuki Nakamura, Machiko China, Hajime Kimura, Sadao Manabe2011 Volume 59 Issue 3 Pages 363-366
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSThree experiments were conducted to evaluate the effectiveness of inactivated iridovirus vaccine for the orange spotted grouper Epinephelus coioides. The first experiment was conducted to confirm the effectiveness of inactivated iridovirus vaccine against red sea bream iridovirus (RSIV) Ehime-1 strain in three different sizes of grouper (5.1 g, 13.1 g, 46.1 g BW). Ten days after immunization with the inactivated vaccine, fishes were challenged with the RSIV. Compared with the control groups, the vaccinated groups showed significantly higher survival rates. The second experiment was conducted with 5 g BW fishes to evaluate the vaccine effectiveness for RSIV Okinawa strain. This experiment showed the effectiveness of the vaccine against RSIV Okinawa strain. The third experiment was conducted to confirm the duration of immunity conferred by the vaccination against the RSIV Ehime-1 strain. This experiment was conducted using 58 g BW fishes that were vaccinated 22 weeks before challenge. The effectiveness of the vaccine was confirmed, demonstrating that the immunity lasted at least 22 weeks.View full abstractDownload PDF (271K) -
Takafumi Okada, Masayuki Yoshida2011 Volume 59 Issue 3 Pages 367-373
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSWe developed a simple and easy-to-use software for analyzing video-recorded behavior of fish. Although the software did not implement automated animal tracking, it markedly reduced the intensive labor required for quantitative analysis of behaviors. The software is able to register basic information on the behaviors of multiple fish including positions, moving velocities, and distances between individuals. Using this software, we analyzed antipredator behavior of a medaka Oryzias latipes shoal induced by presenting a rod that was dropped from above the water to penetrate the water surface. The swimming speed of the fish started to increase just before rod made contact with the water surface. A decrease in distances between individuals was observed concomitantly with an increase in the swimming speed. Although the swimming speed returned to the resting level immediately after the rod was removed, shoal density was relatively high for some time. The results showed that the software was useful for the quantitative analysis of behavior involving quick movements such as antipredator behavior.View full abstractDownload PDF (501K) -
Tatsunari Mori, Setsuo Saito, Taihei Matsuda, Takaaki Kayaba, Chiharu ...2011 Volume 59 Issue 3 Pages 375-382
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSThe effects of rearing temperature and genetic factor on the sex ratio of normal and gynogenetic diploids were examined in barfin flounder Verasper moseri. In addition, growth performance at the age of 6 to 34 months after hatching was also examined. In 16°C (16.1±0.14) group, the percentage of females in gynogenetic diploids (G1) and normal diploids (2N) was significantly lower than in 14°C (13.6±0.33) and 12°C (12.0±0.30) group. However, no clear difference was observed in the female rate between 14°C and 12°C group. These results indicated that rearing temperature affects the sex ratio of both G1 and 2N, and high temperature (16°C) condition induced male-biased sex ratios. Among gynogenetic strains, female rates widely varied from 7.0% to 95.1% in the 14°C and 12°C condition. However, several cases exhibited high female rates (89.5 to 95.1%), suggesting that this species essentially has the male heterogametic (XX female-XY male) sex determination system. At 34 months, body weight of G1 (1569.0±328.4 g) was significantly heavier than 2N (866.6±283.8 g). Survival rates of 2N and G1 from 6 to 34 months were 98.0% and 96.0%, respectively. These results indicate that the group with a high percentage of females showed better growth.View full abstractDownload PDF (193K) -
Hou Chew Ha, Shigeharu Senoo, Kazunobu Tsunemoto, Yoshizumi Nakagawa, ...2011 Volume 59 Issue 3 Pages 383-391
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSTo investigate the population structure of the marble goby Oxyeleotris marmorata in Southeast Asia, a total of eighty-five samples were collected from three regions (the mainland, the peninsula, and the islands) for mitochondrial DNA analysis. Sampling locations that were geographically close were pooled and treated as a single population. Fourteen haplotypes were detected among all the samples. Hap-5 was the most widespread haplotype among the six populations, comprising of 29.4% of all samples. Both the non-significant values of Tajima’s D and Fu’s FS suggested that all populations were at equilibrium. Analysis of molecular variance (AMOVA) revealed significant differences among and within populations, and no variance was due to regional site (FCT = -0.1498, P > 0.05). In pairwise comparisons of FST, Ayutthaya, Dong Nai and Sabah showed significant values between the all populations. The negative values of FST showed that Sarawak, Indonesia, and West Malaysia are less genetically different. This suggests that the marble goby in Ayutthaya, Dong Nai and Sabah may be genetically differentiated populations compared to the other populations in Southeast Asia.View full abstractDownload PDF (190K) -
Yoichi Minami2011 Volume 59 Issue 3 Pages 393-401
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSWe obtained 3,521,600 and 1,760,000 fertilized eggs of Holothuria nobilis and H. scabra, respectively, bred them by the density of 0.08-0.50 individual/ml, and observed the growth of fertilized eggs, larvae, and juveniles. We distinguished the planktonic stages breeding, of which the doliolaria stage and later stages accounted for 50% of all stages, from the benthic stage breeding after that. We fed Cheatoceros gracilis during the planktonic stages breeding, and benthic diatom cultures during benthic stage breeding. The planktonic periods of H. nobilis and H. scabra were 44-51 days and 18-25 days, respectively. We acquired 10,392 juveniles (about 20 mm) of H. nobilis and 7,118 juveniles (about 20 mm) of H. scabra after 92-187 days of juvenile breeding.View full abstractDownload PDF (1145K) -
Norio Shirafuji, Naoto Murakami, Taizo Morioka, Takashi Ichikawa, Kyoh ...2011 Volume 59 Issue 3 Pages 403-410
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSLarval Pacific herring Clupea pallasii has been considered a potential prey item of juvenile chum salmon Oncorhynchus keta because they share habitat in the coastal area of northern Japan, in spring. We experimented on predation of larval herring by juvenile salmon in captivity. The juvenile salmon fed 4.7-7.4% body weight of live and the frozen-thawed larval herrings. The larvae were digested quickly in the stomach and 50% of them were evacuated from the stomach in 2-4 hours. They were morphologically identifiable up to 3-6 hours after being fed. Quick digestion and short duration time of fish in the stomach need to be considered in field surveys of salmon feeding habit. Predation mortality by juvenile salmon may have considerable impact on larval survival of herring.View full abstractDownload PDF (482K) -
Takaaki Shimizu, Motohiro Takagi2011 Volume 59 Issue 3 Pages 411-418
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSDifferences and uniformity in allozyme genetic variability were studied among two wild (W2), three naturally-seeded (A1), and two artificially-seeded populations (hybrid individuals: artificially bred×naturally seeded, A2) of Japanese pearl oyster Pinctada fucata martensi from Uwa Sea, Ehime Prefecture and compared to wild populations (W1) from the Pacific Ocean side of Shizuoka Prefecture. All specimens were collected in early 1997. Nineteen loci (with fifteen polymorphic) were scored by horizontal starch gel electrophoresis. When compared, wild and naturally-seeded populations (W1, W2 and A1) exhibited only low levels of genetic difference, while naturally-seeded populations revealed slight reductions in genetic diversity in their expected heterozygosities. Genetic distance (D=0.002-0.009) and Fst value (0.046) reflected the genetic continuity of the specimens examined. A dendrogram produced using UPGMA showed monophyletic relationships among W1, W2 and A1 populations, connected with the A2 population (bootstrap probability (bp) = 96.9%). On the other hand, two artificially-seeded populations (A2) showed less genetic variability in the number of polymorphic loci and alleles. Genetic distance and Fst value revealed genetic discontinuity not just among all populations (v.s. W1, W2 and A1: D=0.014-0.024; pairwise Fst= 0.023-0.088) but also between the two A2 populations (D=0.050; Fst = 0.161). We consider that reduced genetic variability and genetic discontinuity arose via the artificial seeding of P. f. martensi. In terms of the production of cultured pearls, artificially-cultured populations of P. f. martensi may exert genetic influences upon wild resources if the former zygotes are widely released into the natural habitat.View full abstractDownload PDF (368K) -
Temporal Changes in Exploratory Behaviors of Goldfish Elicited by the Presentation of a Novel ObjectJumpei Nakamura, Masayuki Yoshida2011 Volume 59 Issue 3 Pages 419-425
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSTemporal changes in the exploratory behaviors of goldfish in response to the presentation of a novel object were investigated. A colored plastic bead was presented as a novel object for 30 min, and behavioral responses such as the number and time of approaches to the object, the number of orienting responses, and the number of direct touches with the mouth were counted. Orienting responses and direct touches with the mouth were considered to represent more positive behaviors. The above trial was performed once a day for 7 days and the color of the bead was changed on day 6 of the experiment. The frequency of positive behaviors increased as bead presentation was repeated daily. However, on days 4 and 5 of the experiment, the frequency of exploratory behaviors decreased toward the end of the presentation period, suggesting that the novelty of the object had gradually attenuated. After attenuation, however, the object was observed to partly regain its novelty with change in color.View full abstractDownload PDF (357K) -
Tomoyuki Nakamura2011 Volume 59 Issue 3 Pages 427-433
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSThe relationships between physical characteristics of pools (longitudinal length, maximum depth and presence of refuge as interstitial spaces under boulders and rocks) and residency of adult (age 2 and older) stream-dwelling white-spotted charr Salvelinus leucomaenis were examined using the mark and recapture data obtained in a central Japanese mountain stream over a 4 year period. No significant relationship was observed between the length and maximum depth of pools and PRF (proportion of resident fish: proportions of charr that were recaptured in the same pool where they had been previously captured within 365 days). On the other hand, PRF was significantly higher in the pools with refuge than in those without it. The results show that adult white-spotted charr have a tendency to be resident in pools with refuge.View full abstractDownload PDF (235K) -
Koji Mizuta, Toshifumi Yamatogi, Junya Higano, Akio Tamaki2011 Volume 59 Issue 3 Pages 435-442
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSMass mortality of Manila clams occurring occasionally during summer in different years on intertidal fishery grounds along the northern coast of Isahaya Bay in Ariake Sound is ascribed to raphidophyte outbreaks and low dissolved oxygen concentrations during submergence. To prevent mortality, clams enclosed in cages were kept suspended at depths that are free from these factors in the offshore water column. The survival of clams (28-mm mean shell length) was monitored off three fishery grounds for 41 days during July to September, 2008. Different water depths (1.5, 2.5 m) and cage-exchange frequencies (0, 2) were tested. At the same time the survival of clams (25-45 mm shell lengths) on one fishery ground was monitored for 60 days. Following the cage experiment, the clams were transported back to the fishery ground and maintained until March, 2009. The final survival rates in the three programs were 90-97% (cages), 11% (ground), and 84% (back transplantation). On cages with no exchanges for 56 days, clams were covered with fouling organisms, resulting in recovery failure. As the degree of the coverage is temporally variable, a recommended schedule for caging is the entire duration of < 1 month, exchanging in 2 weeks.View full abstractDownload PDF (539K) -
Sharifah Rahmah, Shinji Yamamoto, Yoshizumi Nakagawa, Keitaro Kato, S ...2011 Volume 59 Issue 3 Pages 443-450
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSDevelopment of morphology, sensory organs and behavior were described for bagrid catfish Mystus nemurus larvae from 0 to 15 days after hatching reared at 28-29°C. First feeding with rotifer (Brachionus plicatilis sp. complex) was observed at 36 hours after hatching (hAH) when the yolk sac absorption was 66.1% and nearly completed at 72 hAH. At this time, the larvae displayed aggregation and foraging behavior as well as negative thigmotaxis and positive rheotaxis. These behaviors corresponded with the development of semicircular canals, disappearance of adhesive characteristics at the tips of the maxillary barbel, increasing growth of pectoral fin, opening of mouth and anus as well as peristaltic movement of the intestinal tract. Negative phototaxis and day time foraging coincided with the appearance of deep pigmented eye, single cone cells and optic nerve while night time feeding possibly relied more on taste buds, olfactory organ and free neuromasts. Cannibalistic behavior was first observed at 54 hAH and this corresponded with the initial appearance of teeth. In this study, relationship among the development of morphology, sensory organs and behavior provides fundamental understanding which suggest possible improvement of larval rearing techniques for bagrid catfish.View full abstractDownload PDF (604K) -
Possible Role of Microalga Nannochloropsis in Controlling Vibrio Species in Fish Larva Rearing WaterAkito Taniguchi, Noor Emilia Sharifah, Mitsuru Eguchi2011 Volume 59 Issue 3 Pages 451-458
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSWe performed duplicate microcosm experiments to determine Vibrio species dynamics over 13 days in enriched natural seawater inoculated with Nannochloropsis. Chlorophyll a concentrations in Tanks 1 and 2 ranged from 8.71 to 235μg/l and 10.9 to 255μg/l, respectively; peak values were recorded on Day 6 in both tanks. Culturable Vibrio abundance on TCBS agar decreased from 180 CFU/ml on Day 2 to 50 CFU/ml on Day 5 in Tank 1, and from 120 CFU/ml on Day 1 to 20 CFU/ml on Day 6 in Tank 2. Total Vibrio abundance estimated by qPCR ranged from 3.2×102 to 2.6×104 cells/ml in Tank 1 and from 2.2×102 to 1.6×104 cells/ml in Tank 2. Interestingly, after the peak of chlorophyll a concentration in both tanks, no culturable Vibrio and only a few total Vibrio were detected. PCR-DGGE analysis showed that the Vibrio community was unexpectedly diverse at the onset, but the structure became simpler over time with the increasing chlorophyll a concentration. Hence, the addition of Nannochloropsis to larval-rearing water may control Vibrio species growth, a key factor responsible for the survival and growth of fish larvae.View full abstractDownload PDF (288K) -
Kei’ichiro Iguchi, Shizuo Aino, Satoshi Awata, Taiga Yodo, Yasuh ...2011 Volume 59 Issue 3 Pages 459-464
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSRecent changes in body size of an annual and amphidromous fish, ayu Plecoglossus altivelis, were investigated in Sho River, Toyama Prefecture, Japan to understand factors affecting the growth. In this study, body size of ayu captured by line-fishing in September of the early 1990’s was compared with that in the late 2000’s; age, hatching date and migration timing from the sea to Sho River of the 2010-year class ayu were determined by counting daily rings on their otoliths and examination of otolith Sr/Ca profiles. In the late 2000’s, especially in the most recent years (2008-2010), fish grew smaller than those during the early 1990’s. Hatching date and migratory timing to freshwater of the 2010-year class ayu were approximately one month later than those in 1990’s. Individual variation in body size of fish in 2010 was explicable by the period spent in the freshwater but not in the sea. Scenario that a deluge causes the extermination of offspring spawned earlier in the season was discussed as a possible triggering factor of miniaturization of ayu.View full abstractDownload PDF (431K) -
Hung Phuc Nguyen, Peerapon Khaoian, Takahiro Furutani, Junya Nagano, ...2011 Volume 59 Issue 3 Pages 465-472
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSA feeding experiment was conducted to investigate effects of alcohol extract from defatted soybean meal (SBM) on secretion of pancreatic digestive enzymes and bile acids in yellowtail. Four diets which were designated as SBM, ExSBM (alcohol extracted SBM) and ExSBM+Ext (ExSBM supplemented with alcohol extract) and FM (fish meal) were fed to yellowtail for 3 weeks. Total bile acid level in anterior intestinal digesta was significantly lower in fish fed ExSBM+Ext and SBM than in fish fed ExSBM and FM, despite similar levels in gallbladder among the treatments. Fish fed ExSBM+Ext and SBM showed lower lipase and trypsin activities in anterior intestinal digesta than fish fed ExSBM which presented comparable values to those fed FM. The activities of these enzymes in pyloric caeca of the former fish were slightly higher than those in the later fish. Growth performance tended to be higher in fish fed ExSBM and FM compared to those fed ExSBM+Ext and SBM though no significant differences were observed after 3-week feeding. These findings indicate that alcohol extract from soybean meal inhibits the secretion of bile acids and pancreatic enzymes in yellowtail. This negative effect on digestive physiology might impair growth in a long-term feeding period.View full abstractDownload PDF (160K)
Note
-
Ryosuke Yazawa, Yutaka Takeuchi, Gaku Iwata, Naoki Kabeya, Akira Komod ...2011 Volume 59 Issue 3 Pages 473-481
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSOur ultimate aim is broodstock management and successful spawning of the Pacific bluefin tuna (PBT) Thunnus orientalis in small, land-based tanks. As a first step toward this goal, we conducted long-term rearing experiments using 0- to 1-year-old PBT in a 70 ｍ3 land-based tank. Given the high mortality observed in 2008 year-class PBT at low water temperatures (January-March; average water temperature, 13.6°C) in the 2008-2009 season, the average water temperature increased to 16.0°C during the same period when rearing 2009 year-class PBT. This increase in temperature prevented high PBT mortality during the low-water-temperature period. The 2009 year-class PBT (total length (TL), 44.5±7.9 cm; body weight (BW), 1.9±0.42 kg) attained lengths of 92.0 cm TL and weighed 13.0 kg BW after 16 months of rearing, which was comparable to PBT reared in marine net-pens. Histological analysis of PBT gonads revealed a significant increase of germ cell number. Moreover, type-B spermatogonia in testes and chromatin nucleolus stage oocytes in the ovary were observed in the 18-month-old PBT reared in this study. These results indicated that gonadal development, including proliferation and differentiation of the germ cells, had proceeded in PBT reared in the 70 ｍ3 land-based tank.View full abstractDownload PDF (976K) -
Tomonori Kuwada, Tetsuya Tokuhara2011 Volume 59 Issue 3 Pages 483-487
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSWe searched for the spawning area of the sea run form of amago salmon Oncorhynchus masou ishikawae which is an endangered fish in a small tributary of the Nagara River system in central Honshu, and surveyed the location, size, water depth, current velocity and substrate size of the spawning redds. The redds (n=22) were observed only at the pool ends and riffles. Averages of the major and minor axis of redds were 129.5±44.9 (SD) cm and 85.0±28.9 cm, respectively. Average water depth was 61.5±16.1 cm. Averages of surface and bottom velocity were 42.0±15.5 cm/sec and 25.9±10.7 cm/sec, respectively. Fine pebble (16-63 mm) was the preferred substrate size. Characteristics of redds observed in our study resembled those of the O. masou group reported in previous studies. It is considered that to conserve wild stocks of the sea run form of amago salmon in the Nagara River, maintaining the physical characteristics of the spawning area mentioned above is important.View full abstractDownload PDF (319K) -
Toshihiro Wada, Kyoichi Kamiyama, Takaaki Kayaba, Masayoshi Sasaki2011 Volume 59 Issue 3 Pages 489-497
Published: September 20, 2011
Released on J-STAGE: October 08, 2012
JOURNAL FREE ACCESSThe annual fishery data of two fishery cooperatives (Onahama, OH; Onahamakisen-sokobikiami, OS) in Fukushima Prefecture (37°N), eastern Japan, from 1986 (OS) /1989 (OH) to 1999 were investigated to elucidate the commercial landings and values of a depleted flounder Verasper moseri. The commercial landings of V. moseri have recently been recovering through mass release programs in Hokkaido (42°N). Fishery data indicated that V. moseri was landed continuously during the survey periods, except for two years in OS, and had the lowest mean annual landed weight (OH, 44 kg; OS, 26 kg) among flatfishes, but showed the second highest average unit price (OH, 3,097 Yen/kg; OS, 2,729 Yen/kg) following the congener V. variegatus (OH, 4,036 Yen/kg). Analyses of daily fishery records of a bottom-trawl fishing vessel during 1986-1991 revealed that V. moseri were caught at the upper continental slope in the Joban area off Fukushima at depths of 204-315 m (mean 272.5 m), which was deeper than nine flatfish species except for two deeper-dwelling flatfishes Hippoglossoides dubius and Clidoderma asperrimum. Our study will help in promoting the effective stock enhancement programs of V. moseri, which would increase the fishery recruits of stocked population from Hokkaido to the Joban area.View full abstractDownload PDF (875K)
- |<
- <
- 1
- >
- >|