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Volume 63, Issue 2
Displaying 1-13 of 13 articles from this issue
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Original Paper
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Takayuki Minami, Kazuo Iwata, Masakazu Kuwahara, Kenichi Amano, Atushi ...2015 Volume 63 Issue 2 Pages 119-125
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe commercial Streptococcus iniae vaccine for Japanese flounder Paralichthys olivaceus can be applied to thread-sail filefish Stephanolepis cirrhifer to induce protective immunity against Streptococcus iniae infection. In the present study, the vaccine was used to determine the optimum route of immunization and the initiation time of protective immunity in thread-sail filefish. A clinical trial investigating the use of the vaccine was also conducted in fish farms where thread-sail filefish were cultured. Mortality was significantly lower in fish that had been vaccinated by intraperitoneal or intramuscular injection than in fish that had not been vaccinated (control group). Strong protective immunity was induced fourteen days after the vaccination. Furthermore, we confirmed the safety of the practical use of the Streptococcus iniae vaccine in farms to immunize cultured thread-sail filefish.View full abstractDownload PDF (468K) -
Hiroshi Hashimoto, Tomohiro Hayashi, Katsuyuki Hamasaki, Hiroyuki Mats ...2015 Volume 63 Issue 2 Pages 127-134
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSVariations in growth rates are associated with increased aggressive behavior and cannibalism during greater amberjack Seriola dumerili seed production. We evaluated the effect of Artemia feeding schedule on variations in growth rate. Fish were divided into four treatment groups (T1-T4) and fed Artemia from 13 days post hatching (dph) [T1, 5.5 mm total length (TL)], 16 dph (T2, 7 mm TL), 20 dph (T3, 9 mm TL), or were not fed (T4) Artemia. Variations in body size, represented by the coefficient of variation (CV) of TL, were negatively correlated with fish dph at the onset of Artemia feeding; earlier ingestion of Artemia was associated with increased growth variation. The T4 CV values were similar to those in T1, because T4 contained a large proportion of small food-limited individuals. The proportion of fish consuming Artemia was significantly lower in T1 than that in the other groups. The amount of Artemia consumed tended to increase after fish reached 6 mm TL. Fish nutritional condition was estimated using the protein/DNA ratio and tended to be highest in T3. Our results suggest that feeding on Artemia before all fish can consume larger prey increases the variation in growth rate.View full abstractDownload PDF (515K) -
Takumi Nakajima, Atsushi Fukui, Nobuhiro Suzuki, Sho Tanaka2015 Volume 63 Issue 2 Pages 135-139
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSBurrowing and migration of adult Strombus luhuanus in the coral sand gravel area in the Acropora tumida community off Kuzura, Numazu, Shizuoka, Japan, were investigated using a sequential quadrat (3×3 m) and capture-mark-recapture sampling methods. The occurrence of individuals (468-826) and burrowing ratio (30.3-95.5%) were high when water temperature was below 16°C (January-March). Many marked individuals were found near the quadrat, which was the release point, indicating short daily average migration distance (10.1-49.0 cm). Conversely, lower numbers (10-235) occurred in the quadrat when the water temperature increased from 16°C to 26°C (April-August) and decreased from 26°C to 16°C (September-December). During these periods, their burrowing ratios were also low (0-40.5%), and the daily average migration distances of marked individuals were also long (54.5-890.1 cm), resulting in fewer individuals remaining near the released point. Hence, it can be concluded that the sluggish movement of S. luhuanus during the cold months appears to be one strategy for survival of this species in the most northern habitat.View full abstractDownload PDF (4217K) -
Hikaru Yamane, Ayumi Yoshida, Hideki Yamazaki, Kazutaka Sakiyama, Yuuk ...2015 Volume 63 Issue 2 Pages 141-149
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe behavior and feeding habits of different sizes of hatchery-reared tiger puffer fish Takifugu rubripes were investigated. Five juveniles of each size group (3.2±0.2 cm, 4.9±0.2 cm, 6.2±0.3 cm, 9.5±0.5 cm SL) were placed in a tank containing 32 psu water (control) and a tank containing salinity-gradient (10-32 psu) water, and the vertical distribution (surface, middle, bottom) of the fish was determined after 3 h. Large juveniles (6.2±0.3 cm and 9.5±0.5 cm SL) swam to the surface layer of the salinity-gradient tank more frequently (27-89%) than the control tank (4-51%) during 1-3 h after transfer. The settling behavior of juveniles (5.5±0.3 cm and 10.9±0.7 cm SL) at 15 and 32 psu, and using static and spring water was also investigated. Settlement rate of small (5.5±0.3 cm SL) juveniles was significantly lower (P<0.0001) than large (10.9±0.7 cm SL) juveniles. Spring-water and 15 psu stimulated settlement in both sizes. Feeding preference of puffer fish juveniles (5.4±0.6 cm, 8.9±1.0 cm SL) with or without sand as substrate was also investigated. Fish showed active feeding without sand, and 83% of the large juveniles (8.9±1.0 cm in SL) fed on bivalves, while only 42% of that small juveniles (5.4±0.6 cm SL) fed on bivalves. Overall results showed that hatchery-reared tiger puffer juveniles prefer low salinity (10-16 psu) environment, became benthic as the size increases, and eat benthic food item like bivalves when they are over 6 cm in SL.View full abstractDownload PDF (716K) -
Yuka Oda, Tetsuro Kitagawa, Kazumi Hosoya2015 Volume 63 Issue 2 Pages 151-158
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe purpose of this study was to develop a technique for artificial propagation for bitterlings under a completely artificial environment by injecting Chinese rosy bitterlings, Rhodeus ocellatus ocellatus, an experimental animal, with a hormone. Salmon pituitary extract or 17α-hydroxyprogesterone was injected into the abdominal cavity of female rosy bitterlings in the laboratory. Females with an ovipositor prolonged by the hormone injection were stripped of their eggs after 24 h. Salmon pituitary extract and 17α-hydroxyprogesterone induced females to elongate the ovipositor and mature gonad (Steel-dwass test, P<0.05). However, the ovipositor that was induced by 17α-hydroxyprogesterone injection, was regarded as an aberration. Incidentally, eighty-three eggs were obtained from females into which salmon pituitary extract had been injected; thereby, seventeen larvae emerged. The ripe stage oocyte and regressing oocyte were observed in sections of the gonads. These results show that salmon pituitary extract is effective in inducing ovulation of the rosy bitterling.View full abstractDownload PDF (796K) -
Yang-Su Kim, Amal Biswas, Seung Chul Ji, Osamu Murata, Kenji Takii2015 Volume 63 Issue 2 Pages 159-167
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe effect of graded levels of phytase in soybean meal (SBM) diets on the growth performance and phosphorus availability was investigated in hybrid (F1), female red sea bream × male black sea bream. Six diets were formulated: as fish meal (FM) 46% (control), FM 15% + SBM 40% (SP0), and 1000, 2000, 3000 and 4000 phytase activity units/kg in SP0 diet (SP1000, SP2000, SP3000 and SP4000, respectively). Ten juvenile F1 with mean body weight ca. 76 g were assigned into each of triplicate 400 l tanks for each treatment and were fed for 16 weeks at 20°C. The apparent digestibility coefficient (ADC) was measured using Cr2O3 as an inert marker. The growth performances, protein retention efficiency and ADC of protein were not significantly different among the dietary groups. However, carcass phosphorus retention and vertebra phosphorus accumulation were significantly higher, and phosphorus discharge was significantly lower in SP2000 and SP3000 than those of SP0. These results suggested that 40% SBM diet can be utilized by F1, phytase supplementation in the SBM diet improves phosphorus availability, and suitable phytase supplementation level was approximated at 2000 unit/kg in SP0 diet for F1.View full abstractDownload PDF (262K) -
Noriko Hosomi, Toshiro Masumoto, Haruhisa Fukada2015 Volume 63 Issue 2 Pages 169-178
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSMelanin-concentrating hormone 1 (MCH1) is an appetite-regulating hormone in vertebrates, but its functioning differs among species. Understanding the underlying mechanism of appetite regulation is important to improve production performance in aquaculture systems. The yellowtail Seriola quinqueradiata is one of the most cultured fish species in Japan, although little is known about its appetite-regulating hormones. In the present study, complementary DNA encoding for MCH1 was cloned in yellowtail. Cloned cDNA consisted of 599 bp, whereby the deduced mature MCH1 amino acid sequences showed high degree of identity with those from other teleosts. The phylogenetic analysis revealed that yellowtail preproMCH1 belongs to the MCH1 group. In terms of tissue distribution, the mch1 mRNAs were detected in all examined tissues (whole brain, telencephalon, optic tectum, hypothalamus, cerebellum, pituitary, retina, stomach, pyloric caeca, anterior intestine, liver, and kidney). The mch1 mRNA expression in the brain did not show significant differences after fasting when compared to the control group. However, mch1 mRNA expression in the hypothalamus decreased significantly after feeding, in fish previously fasted for 72 h. Further studies are needed to identify the role of MCH1 in feeding regulation in yellowtail.View full abstractDownload PDF (1290K) -
Taro Matsumoto, Yasuo Agawa, Tokihiko Okada, Yoshifumi Sawada, Yasunor ...2015 Volume 63 Issue 2 Pages 179-189
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe kawakawa is an important migratory fish species in the subtropical to tropical Indo-West Pacific Ocean. Despite the high commercial importance of this species, its ecological and physiological features are not well understood. To provide an in-depth characterization of this species, we sequenced its opsin visual pigment gene by rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR). We found 11 opsin genes as follows: Rh1 (rod opsin); Rh2A1, Rh2A2, g6738, g6740, Rh2B1, and Rh2B2 (green sensitive); SWS1 (ultraviolet or violet sensitive); SWS2A and SWS2B (blue sensitive); and LWS (yellow-red sensitive). These results suggested that the kawakawa possesses broad spectral vision from violet to red light. To the best of our knowledge, this is the first study to report the presence of six Rh2 opsin genes from marine fish.View full abstractDownload PDF (436K)
Short Paper
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Seiya Ishiguro, Masashi Yokota, Zhang Zhixin, Yoh Usami, Ryuji Watana ...2015 Volume 63 Issue 2 Pages 191-194
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe survival of Chinese and Japanese mitten crabs in the absence of water was compared to obtain basic information on their invasion ability through land. The survival time of crabs in dry conditions varied greatly among individuals but there were no significant differences among species. Most crabs were able to survive more than two days in the absence of water. These results indicate that Chinese mitten crab has similar ability to move on land as the Japanese mitten crab and suggest that it might potentially invade aquatic habitats by escaping from commercial transportation.View full abstractDownload PDF (365K) -
A. M. Shahabuddin, Mohammad Nakib Dad Khan, Novi Arisman, Debasish ...2015 Volume 63 Issue 2 Pages 195-197
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSA new dietary ingredient "Pyropia spheroplasts (PS)" was prepared from Pyropia yezoensis through enzymatic treatment. Four diets (PS inclusion levels of 1%, 2% and 3% body weight basis, and live diatom Chaetoceros calcitrans) were fed to the three replicate groups of clams for 9 weeks in a flow-through system. Significantly higher survival was obtained in all PS dietary groups (P<0.05). PS level 2% showed higher carcass weight compared to the other PS diets and was not different than control (P>0.05). Results indicate PS to be a good candidate for a substitute to live food for culturing short-neck clams.View full abstractDownload PDF (50K) -
Masaki Hata, Noriko Otsuki, Hiroki Tanaka, Takeshi Tomiyama, Jun Shoji2015 Volume 63 Issue 2 Pages 199-201
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSSpotted halibut Verasper variegatus juveniles were first collected from tidal flats around river mouths in Hiroshima Prefecture, the central Seto Inland Sea. A juvenile of 24.0 mm total length (TL) was collected from the Kurose River, Kure City, on 18 March 2014 and another of 63.0 mm TL from the Kamo River, Takehara City, on 30 May 2014. Salinity at the sampling sites ranged 3.7-14.7. The juveniles fed mainly on crustaceans such as amphipods and mysids. Tidal flats with low salinity are suggested as one of the juvenile habitats in the Seto Inland Sea.View full abstractDownload PDF (247K) -
Hisao Ogawa, Show-Mei Lin, Teng-Yi Huang, Li-Chia Liu, Chung-Zen S ...2015 Volume 63 Issue 2 Pages 203-206
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSThe study examined the possibility of Undaria pinnatifida cultivation in Taiwan. Although a temperature of 23°C was favorable for the growth of the gametophyte, propagation was possible in the laboratory at 24-27°C when seawater was enriched with nutrients. The maturation of gametophytes occurred on the shelves in the laboratory at 24-27°C, and juvenile sporophytes were formed from the cultured gametophyte and grew at 17°C. The cultivation of U. pinnatifida is thought to be possible in Taiwan, because the sea surface temperature ranges in12-26°C in the coastal area of Kinmen and Matsu Islands, Taiwan.View full abstractDownload PDF (378K)
Note
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Hiroyuki Doi, Toshiaki Ishibashi, Harumi Sakai2015 Volume 63 Issue 2 Pages 207-212
Published: June 20, 2015
Released on J-STAGE: June 20, 2016
JOURNAL FREE ACCESSCyclichthys orbicularis (Diodontidae, Tetraodontiformes) were spawned in captivity, the larvae being reared for more than 60 days, in the Shimonoseki Marine Science Museum Aquarium. Isolated epipelagic eggs, 2.2 mm in mean diameter, hatched two days after spawning. Hatched larvae were 3.5 mm in total length, the head and trunk being covered by a "vesicular dermal sac". Fin rays were completed in 17 days after hatching at 7.6 mm TL, some rudimentary spines appearing on the dorsum. Spines had become unmovable in 39 days after hatching at 20.8 mm TL. Growth rates from hatching to 8 days and thereafter from 9 days were different, growth regression equations between TL (y) and days after hatching (x) being y = 0.052x + 3.518 and y = 0.295x + 2.046, respectively.View full abstractDownload PDF (1126K)
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