日本水産学会誌
Online ISSN : 1349-998X
Print ISSN : 0021-5392
ISSN-L : 0021-5392
56 巻, 2 号
選択された号の論文の28件中1~28を表示しています
  • 町井 紀之, 能勢 幸雄
    1990 年 56 巻 2 号 p. 173-178
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The mechanical properties with factors of forces (tension; F and drag; D), velocity (v) and distance (s), in a normal operation were studied. Normal operation means pulling both ends of the purse line by a winch during the pursing stage and the hauling stage. The mechanical pro-perties at the equilibrium condition of the force were expressed in the pursing stage (suffix “1”) as; η1=e-πμ1, F1=(Fwcosθ1)/2, D1=πη1Fwcosθ1, v1=(Vwcosθ1)/(πη1) and s1={(Vwcosθ1)/(πη1)}t, where θ1=sin-1 (W/Fw), and in the hauling stage (suffix “2”) (vertical pulling) as; v2=1.0, F2=Fw/2, D2=Fw-W, v2=Vw and s2=Vw(t-t1). Where η1 and η2 are the mechanical ef-ficiencies between the purse line and the ring, μ1 is the kinetic friction coefficient between the purse line and the ring, Fw is the tension of the winch, W is the weight in water of the fishing gear, Vw is the velocity of the winch, and t1 and t2 are the time lapses during a fishing operation. If the factors μ1, Fw, W, Vw, t1 and t2 are given as known constants, each factor of the mechanical pro-perties can be calculated.
  • 真野 季弘
    1990 年 56 巻 2 号 p. 179-187
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Some observations of sperm whales in natural conditions were made with a sonar of 20kHz at night-time in the coastal waters of Japan in 1985 and 1987 on board a whaler. The whalesdove to a maximum of 730m, or 30-162m in respective means, during diving observations of 5-13h.
    The surfacing and diving Feriods of the whales were 1-32 min, or 9 min in mean, and 1-47 min, or 10 min in mean respectively. However, the diving period of medium sized bachelors was relatively short, from 3-23 min. The above periods were longer in comparison than with dives during critical conditions as when chased by commercial whalers.
    The whales swim at speeds of 0-6kt or 3kt in mean, and medium sized bachelors generally swim faster than large bachelors.
    The whales swim along an 18°C-isotherm of surface temperatner, and often along or across “Shiome.”
  • 石松 惇, 丸田 肇, 土山 高史, 尾崎 正若
    1990 年 56 巻 2 号 p. 189-199
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    To clarify the mechanisms by which the yellowtail Seriola quinqueradiata are killed by the red tide plankton Chattonella, an analysis was made on physiological responses of the fish exposed to the plankton. Fish were chronically cannulated in the dorsal aorta and gill cavity. Changes in respiratory, ionic and cardiovascular parameters were followed until death. Soon after exposure, a severe hypoxemia developed which was accompanied by a marked increase in ventilatory pulse pressure, though the latter subsequently subsided. No acidosis occurred until shortly before death despite the persistent hypoxemia. Plasma concentrations of Na+, K+, Cl-, Mg2+, and Ca2+ were all elevated to different magnitudes. Blood pressure responses varied among fish, but arrhythmia was the predominant response. Heart rate gradually declined or remained unchanged until shortly before death. Gill ventilatory frequency changed very little during most of the exposure period. These results were critically discussed in the light of data reported previously.
  • 広田 祐一, 輿石 裕一, 長沼 典子
    1990 年 56 巻 2 号 p. 201-206
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Juvenile flounder Paralichthys olivaceus in the Sea of Japan mainly fed on mysids. Five mysid species were identified in the 197 stomachs of the flounder examined, and they contained 1673 specimens of mysids. Acanthomysis robusta was most numerous (93.5%). Other species were Neomysis japonica (5.3%), A. nakazatoi (0.9%), Nipponomysis perminuta (0.2%). Ni. toriumii (0.1%). Total length of broken mysid in stomach was estimated using the regression equations between total length and the six part lengths i.e. carapace length, carapace width, length of 6th abdominal segment, exopod length of uropod, endopod length of uropod and telson length. Maxi-mum size of A. robusta in stomach increased with size of juvenile flounder. Mysid eaten by the flounder less than 20mm in body length was 5.4mm, and ones consumed by the20-25mm and 25-30mm flounder became rapidly larger to 7.4mm and 9.7mm, respectively. Juveniles less than 35mm mainly fed on small mysids less than 5mm, whereas ones greater than 35mm actively fed on large mysids (>30% of mysid number in stomachs).
    The percentage of mysid weight in stomachs to body weight of flounder less than 30mm was peaked (4.9%) in the evening, whereas the percentage dropped to 0% after midnight. A similar diurnal feeding pattern was found for juveniles greater than 30mm.
  • 木本 秀明, 林 泰行, 檜山 節久, 上城 義信, 小川 浩, 林 功, 石田 雅俊, 有江 康章, 伊東 弘, 正木 康昭
    1990 年 56 巻 2 号 p. 207-215
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The stock size of Japanese flounder Limanda yokohamae in Suo-Nada of Seto Inland Sea is considered to be on the decrease, We reexamined parameters of stock characteristics, We proposed a stock management scheme for this stock,
    The adult stock size was estimated to be about half of the level giving the MSY, whichsuggests that the stock is in the overexploited state, Age at recruitment should be raised from 1.3 to 2.0.
  • 瀬川 進
    1990 年 56 巻 2 号 p. 217-222
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Food consumption, food conversion and growth rates of the oval squid Sepioteuthis lessoniana were measured on an individaul basis fed on three kinds of live organisms, namely, fish, mysid and squid hatchling. Squid used in the present study were all reared from egg to the experimental size, ranged from 0.06 to 42.1g in wet body weight in an indoor aquarium. The daily food con-sumption rate ranged from 0 to 72% of body weight and depended upon the growth stage of the squid. Food conversion rate on a wet weight basis ranged from 15.4 to 43.8% and the rate was largely independent of the size of squid. Growth rate of the oval squid decreased with increasing size. The daily growth rate in body weight of hatchling reached 12.9% and that of the squid grown up to 30-50g in body weight ranged from 1.8 to 4.1%. The growth was dependent upon quality of food. Squid fed on squid hatchlings showed the highest growth rate followed by those fed on fish. The daily growth rate increased with each increment of the daily food consumption rate.
  • 高橋 幸則, 伊丹 利明, 中川 敦史, 安部 敏男, 菅 善人
    1990 年 56 巻 2 号 p. 223-227
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The in vitro antibacterial activity of flumequine, a synthetic quinolone antibacterial agent, against Pasteurella piscicida, which causes pseudotuberculosis in yellowtail Seriola quinqueradiata was examined. Subsequently, the in vivo effective dose of the agent and its therapeutic effect in the field were studied.
    Flumequine showed an minimum inhibitory concentration of 0.1-0.39μg/ml against 43 strains of P. piscicida out of 44 strains tested.
    In examining the in vivo effective dose, 5, 10, 15 and 20mg/kg body weight/day of flumequine were administered for 5 days to diseased yellowtail naturally infected with pesudotuberculosis. After completion of administration, the number of dead fish in the group dosed with 20mg/kg was significantly lower than in other groups. Further, 10 and 20mg/kg of flumequine were administer-ed for 5 days, in the field, to diseased yellowtail with pesudotuberculosis. It was found that the numbers of dead fish in the groups administered with flumequine were lower than that in the control group, and that mortalities in the group dosed with 20mg/kg were particularly low.
  • 山光 俊一, 板沢 靖男
    1990 年 56 巻 2 号 p. 229-237
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The isolated perfused heart of carp was examined to study the effects of input pressure (preload), ventral aortic pressure (afterload) and temperature on the intrinsic mechanical properties and ECG of the heart. Increase in both cardiac output ( ?? b) and stroke volume (SVh) and no marked change in heart rate (HR) with increasing preload indicates that the cardiac function is determined basically by preload. No marked response was observed in any of parameters of cardiac function to changing afterload.
    SVh, HR and ECG intervals were highly temperature-sensitive, but ?? b was rather constant in a range of 15 to 35°C. At temperatures lower than 10°C, marked decrease in both ?? b, bradycardia and abnormal extension of ECG intervals were observed. At temperatures higher than 37.5°C, although atrial pulsation was still high, ?? b began to rapidly decrease and the arrest of ventricular pulsation was often observed. At 40°C, a complete cardiac arrest was observed in all preparations.
  • 楠田 理一, 杉浦 浩義, 川合 研児
    1990 年 56 巻 2 号 p. 239-242
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The in vitro antibacterial activity of six chemotherapeutic agents against Pasteurella piscicida was determined. Three hundred and six strains of P. piscicida were isolated from diseased cultured yellowtail Seriola quinqueradiata from 1986 to 1988. Susceptibilities to six chemotherapeutic agents were examined as the minimum inhibitory concentration (MIC), using the method of the Japan Society of Chemotherapy. Resistance to ampicillin (ABPC) and amoxicillin (AMPC) was found in 35% of the strains. Resistance to oxolinic acid (OA) and flumequine (FM) was found in 37% of the strains. High antibacterial activity was demonstrated by novobiocin (NB) and flor-fenicol (FF) and moderatedly high activity by sodium nifurstyrenate (NFS-Na). However, the MIC of NFS-Na varied between 0.2μg/ml and 12.5μg/ml. The resistance pattern could be divided into three groups: the first group was resistant to ABPC and AMPC; the second group was re-sistant to OA and FM; the third group was resistant to ABPC, AMPC, OA and FM. The third group comprised 23% of the strains.
  • 朝比奈 潔, 廣瀬 一美, 日比谷 京
    1990 年 56 巻 2 号 p. 243-247
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Adult topmouth gudgeon Pseudorasbora parva (Cyprinid) were collected monthly for a year in the midstream of the Tama River, Tokyo. Gonadosomatic indices (GSI) and gonadal histology were used as criteria of gonadal maturation. During March and April male and female GSIs in-creased rapidly with the accumulation of yolk globules and active spermatogenesis, respectively. GSIs stayed high during April, May, and June, but decreased drastically in July showing the end of their spawning season. In the post spawning season (August) the ovaries and the testes were filled with yolkless oocytes and proliferating spermatogonia, respectively. During autumn and winter a gradual gonadal recrudescence which was represented by the accumulation of yolk vesicles or meiosis of spermatocytes occurred. These results indicate that the spawning season of P. parva extends from the end of March to the end of June in this sampling area. A possible environ-mental control on the annual reproductive cycles of this species was discussed.
  • 藤岡 康弘, 伏木 省三, 田川 正朋, 小笠原 強, 平野 哲也
    1990 年 56 巻 2 号 p. 249-254
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Seasonal changes in plasma thyroxine concentrations were examined in biwa Oncorhynchus rhodurus and amago salmon O. rhodurus reared in the pond. About 80% of biwa salmon lost parr marks and became silvery in underyearling June. Thereafter, they kept silvery body color until 2-year-old April, when the experiments were terminated. Plasma thyroxine levels in biwa salmon decreased gradually from underyearling spring (about 4 ng/ml) to autumn, reached a lowest level (0.4 ng/ml) in December, and then increased gradually until yearling October (3-4 ng/ml). The relatively high hormone concentrations during underyearling April and May could be related to the body silvering and downstream migration. On the other hand, about 30% of amago salmon became silvery smolts with full seawater adaptability in underyearling autumn and winter. Plasma thyroxine concentrations in amago salmon showed a clear rise during smoltification and a distinct peak at the time of new moon in October (about 8 ng/ml). Thyroxine concentrations were re-latively high prior to the spermiation of precociously matured males (underyearlings) of both biwa and amago salmon, but decreased to a low level during spermiation, suggesting that thyroid hor-mone may also be involved in gonadal development.
  • 内藤 靖彦, 坂本 亘, 内田 至, 呉羽 和男, 海老沢 智幸
    1990 年 56 巻 2 号 p. 255-262
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The adult loggerhead turtles Caretta caretta use the sandy beaches of Japanese Islands as their nesting place. A female went to sea after her first spawning and 20 days later she returned again to the same beach to make a second spawning. Her migration route during this interval was estimated using time series water temperature data directly obtained from the female C. caretta by TTR, and oceanographic survey data. She was thought to arrive at the Kuroshio zone at first and to be drifting for several days in the current. After drifting, she would begin to swim toward the nesting beach, seemingly selecting the direction to arrive at the nesting ground. Therefore any random swimming motion could not be found on her estimated swimming trajectories.
  • 坂本 亘, 内藤 靖彦, 内田 至, 呉羽 和男
    1990 年 56 巻 2 号 p. 263-272
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    A continuous diving recorder and a swimming distance recorder were used to monitor the diving performances and swimming behavior of the free-ranging loggerhead turtle Caretta caretta during her inter-nesting periods. A clear circadian rhythm was found on her diving frequencies and durations in off shore swimming performances while it was obscure at the period during which she swam near coastal area. The circadian rhythm was closely correlated with the sunrise and the sunset. However, this was disturbed by irregular environmental events such as typhoons and when passing through frontal zone. The rhythm was considerably higher when she arrived at coastal zone, It corresponded to the tidal period.
  • 兼廣 春之, 宮崎 喜久, 鈴木 誠
    1990 年 56 巻 2 号 p. 273-280
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Water absorbing behavior of nylon (NY) and polyester (TE) netting twines were investigated by wicking height measurement and soaking method. The following results were obtained.
    The amount of absorbed water soaked up into the twine (Qe) by the former method and the amount of water held after 24h immersion (Wh) by the latter method for three different netting twines showed that the water absorbing properties were largely influenced by the kind of netting materials, the construction of netting twines and treatment with synthetic resins. Both values were found to be in the following decreasing order: NYc (untreated control nylon)>NY>TE.
    From the measurement of changes in weight of netting twines in water during the water absorb-ing process, it was found that the water absorbing behavior was largely influenced by two different treatments with or without rinsing with hot water. From these, it was suggested that the hydro-philic property of the fiber surface affected its water absorbing properties.
    Moreover, from the results of time dependence of water absorption it was found that water absorption of netting twines occurred at two different stages.
  • 石田 典子
    1990 年 56 巻 2 号 p. 281-286
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The tissue levels of oxolinic acid, an antibacterial agent, in fresh water fishes (rainbow trout and tilapia) and sea. water fishes (red sea bream, Japanese mackerel, yellowtail, and Japanese flounder) at 3, 6, 12, 24, 48, and 72h after oral administration (40mg/kg) were determined by high performance liquid chromatography. High concentrations of oxolinic acid were observed in the order of kidney <liver<muscle<serum in all the specises examined. In rainbow trout, each tissue level reached maximum (kidney; 15.0, liver; 5.9, muscle; 4.8, serum; 2, 2μg/g) at 72h post dosing. In tilapia, the highest concentrations of liver (13.0μg/g), muscle (4.9μg/g), and serum (9.1μg/g) were observed at 12h, while that of kidney (11.0μg/g) was found at 48h. In the other 4 species of sea water fish, the drug concentration in each tissue went up to the level of O.3-6.3μg/g within 12h and went down below the loewst detectable limit at 72h. The time required for the tissue level to reach a maximum concentration was shorter in the sea water fish than in the fresh water fish. The tissue level in the sea water fishes was lower than in the fresh water fishes. Thus, oxolinic acid appears to remain much more in the fresh water fishes than in the sea water ones for a long time.
    The drug concentrations in coho salmon cultured in fresh water and sea water were compared. The tissue level in the coho salmon cultured in fresh water show a the similar tendency to that rainbow trout, while the drug concentration in the coho salmon cultured in sea water changed similarly to that of the sea water fish.
  • 松川 雅仁, 岩見 史郎, 新井 健一
    1990 年 56 巻 2 号 p. 287-295
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Effect of addition of inorganic pyrophoshate (PPi) along with MgCl2 on denaturation of myosin B from Carp and Alaska pollack (pH 7.0) was studied.
    When 1.0mM of PPi and of MgCl2 was added to myosin B in a medium containing 0.5 M KCl and 40mM Tris-maleate (pH 7.0) and the mixture was stored at 10°C, the following changes were observed: (1) Viscosity together with ATP-sensitivity (%) of both myosin B decreased. (2) Ca-ATPase specific activity of carp myosin B was almost unchanged, while that of Alaska pollack myosin B was largely decreased. (3) The mode of thermal inactivation of carp myosin B Ca-ATPase changed from a slow single first order process to a biphasic first order process, while that of Alaska pollack myosin B Ca-ATPase remained a slow first order process. (4) The amount of actin together with tropomyosin released into 50mM KCl solution (pH 7.0) from Alaska pollack myosin B was larger than that from carp myosin B.
    These results indicated that a considerable part of both carp and Alaska pollack myosin B was dissociated into actin and myosin upon mixing and storage with PPi-MgCl2, and that the actin released from carp myosin B denatured preferentially, leaving the myosin in a free form, while the actin along with myosin released from Alaska pollack myosin B immediately denatured.
  • 浅川 哲弥, 東 尚巳
    1990 年 56 巻 2 号 p. 297-305
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Abalone myosin was digested with proteases, (trypsin, chymotrypsin, nagarse, papain) in the presence of CaCl2 or EDTA. The time course of the digestion and the properties of degradation products were investigated by SDS-polyacrylamide gel electrophoresis.
    In the presence of CaCl2, myosin light chains were not digested, but in the presence of EDTA, regulatory light chains disappeared at first, followed by SH light chains.
    Heavy meromyosin (HMM) was obtained by tryptic and chymotryptic digestion of abalone myosin. These HMM had multiple cleavages in the heavy chain (HC) region.
    Subfragment-1 (S1) was also obtained by chymotryptic, nagarse and papain digestion and by tryptic digestion in the presence of EDTA. The molecular weight of S1 HC was 90-100 kilodalton (kD). Papain S1 obtained in the presence of CaCl2 had a single HC (94kD) and two light chains, but other S1 had intra-cleavages in the HC region.
    These results indicate that abalone myosin has protesae sensitive region whose cleavage leads to HMM or S1, like skeletal muscle myosin, homogeneous S1 preparation is obtained by diges-tion with papain.
  • 伊藤 雅章, 猪上 徳雄, 信濃 晴雄
    1990 年 56 巻 2 号 p. 307-314
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The effect of concentrated salt solution on the freeze denaturation of carp myosin B was investigated in connection with the length of time taken to freeze to -20°C (freezing time). The apparent rate constants for the inactivation of Ca-ATPase (kf) were calculated on the basis of a -20°C-frozen-storage experiment with various combinations of freezing times and KCl concentra-tions. The slowly frozen sample resulted in a considerable decrease in Ca-, Mg- and EDTA-ATPase activities, and ATP-sensitivity of myosin B. The log kf values were correlated in a definite range with the length of time from the freezing point to the end of the eutectic plateau. A high initial KCl concentration of myosin B solution before freezing and a long freezing time resulted in a large kf value.
    These findings show that the remaining activity is affected by the concentration of unforzen KCl solution and by the length of time of exposure to the concentrated solution.
  • 内田 直行, 渡辺 正治, 垣内 麻由美, 安斉 寛, 西出 英一
    1990 年 56 巻 2 号 p. 315-322
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Fibronectm in the plasma of carp Cyprinus carpio (CpFN)was purified to homogeneity on SDS-PAGE by sequential column chromatographies on thermally denatured carp sking collagen (carp gelatin)-Sepharose 4B, arginine-Sepharose 4B and Sepharose CL-4B.
    The compositions of carbohydrate and amino acid of the purified CpFN were quite similar to those of bovine plasma fibronectin (BpFN) purified by the procedures similar to those for the CpFN. The CpFN reduced with 2-mercaptoethanol showed two bands, 215 kDa and 220 kDa, on SDS-PAGE, and the unreduced CpFN showed a single band of about 440 kDa, suggesting that the CpFN was a disulfide-bonded dimer of two nonidentical subunit polypeptides, which were slightly smaller than those of the BpFN. The CpFN had some fragments resistant to the diges-tion with thermolysin, trypsin, elastase and subtilisine, whose patterns on SDS-PAGE showed distinct differences from those of the BpFN.
  • 太田 亨, 佐々木 茂文, 阿部 茂, 高木 徹
    1990 年 56 巻 2 号 p. 323-327
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    The fatty acid compositions of total lipids from the raw fillets of four species of salmons, the salted fillet and the canned fillets from sockeye salmon were investigated with open-tubular gas-liquid chromatography. The major components of fatty acids of the present samples were similar to those of masu salmon, pink salmon and chum salmon studied previously. Each sample showed the characteristic pattern of the fatty acids. Food products of sockeye salmon have high contents of 20:1 (n-11) and 22:1 (n-11 and n-13). The raw fillet of coho salmon has higher contents of polyunsaturated fatty acids than other samples. Moreover, the contents of 18:2 (n-6) in the raw fillets of rainbow trout and chinook salmon were apparently higher than those of other fish studied. It was inferred that these characters of fatty acid compositions were influenced by the fatty acid patterns of dietary lipids.
  • 李 南赫, 関 伸夫, 加藤 登, 中川 則和, 照井 正三郎, 新井 健一
    1990 年 56 巻 2 号 p. 329-336
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    In this study, changes in breaking strength of the salted meat paste from surimi of threadfin bream and in myosin heavy chain in it were investigated in connection with the temperatures (10-60°C) for setting. The water holding ability of Kamaboko prepared from the salted paste through setting, followed by heating at 90°C, was also examined.
    The most suitable temperature for the increase in breaking strength of the salted paste, along with formation of cross-linked myosin heavy chain in it, were 20-30°C. The Kamaboko prepared through setting under the suitable temperature exhibited high water holding ability. On the contrary, with the rise of temperatures over 40°C, remarkable decreases in breaking strength and the formation of cross-linked myosin heavy chain were noticed. In addition, at setting temperature over 40°C, the Kamaboko made from the salted paste released a water drip together with some soluble proteins. The protein in the water drip amounted to approximately 10% relative to myofibrillar protein content in the salted paste.
  • Deng-Fwu Hwang, Chuang-Hsun Chueh, Sen-Shyong Jeng
    1990 年 56 巻 2 号 p. 337-343
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Marine and freshwater fish (20 species), crustaceans (13 species) and mollusks (19 species) were collected around and in Taiwan, and examined for susceptibility to tetrodotoxin (TTX) and paralytic shellfish poison (PSP). The minimum lethal dose (MLD) of both toxins in most fish were estimated to <10MU/20g body weight on intraperitoneal and intramuscular administrations. Crustaceans (shrimps and crabs) showed the same susceptibility to either toxins. In contrast, most mollusks were much less susceptible to both toxins, with MLDs of TTX being >365MU/20g, and those of PSP being >300MU/10g, on intramuscular injection.
  • 高岡 治, 滝井 健二, 中村 元二, 熊井 英水, 竹田 正彦
    1990 年 56 巻 2 号 p. 345-351
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Feeding stimulants for the marbled rockfish Sebasticus marmoratus were identfied by the omission test uding the synthetic extract of krill Euphausia pacifica. The fish were fed on a purifiedcasein diet supplemented with constituents of the extract for 6 days.
    The feeding stimulant activity was evaluated by the daily feeding rate. The nucleotide fraction of the extract was the most effective, followed by the amino acid fraction which showed a littel activity. Inosine had the highest activity among all constituents of the extract. With increasing supplementary level to the diet, amino acids such as L-alanine, L-methionine, L-serine and L-proline and nucleotides such as adenosine-5'-diphosphate, adenosine-5'-monophosphate and inosine-5'-monophosphate became positive. When inosine together with, L-alanine, L-methionine, L-serine and L-proline was supplemented to the diet, its activity for the fish was remarkably improved, becoming to the synthetic extract.
  • 西島 敏隆, 畑 幸彦, 橋本 尚之
    1990 年 56 巻 2 号 p. 353-359
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
    Freshwater red tides by Plagioselmis sp., a Cryptophyceae, frequently occur in the lower part of the Nakasuji River during the cold seasons. The present paper describes the growth characteristics of Plagioselmis sp. (strain 87) isolated from the river water in 1987.
    The optimum tempreature and light intensity for the growth of Plagioselmis sp. (strain 87) were found to be 10-25°C and 1, 000-14, 000lx. This alga preferred the neutral and lower alkaline pH (7-9).5 and lower salinity (0-3.4‰). The amounts of nitrate, phosphate, and vitamin B12 required to maximize both growth rate and cell yields were 5mg N/l, 0.15mg P/l, and 50ng/ml, respectively. The falf-saturation constants of nitrate, phosphate, and vitamin B12 based on the growth rate were estimated to be 0.15mg N/l, 0.0078mg P/l, and 2.3ng/l, respectively. The minimum cell quotas of nitrogen, phosphorus, and vitamin B12 were 1.5×10-2ng N/cell, 5.5×10-4ng P/cell, and 2.5×10-4pg/cell, respectively.
    Phosphate concentration, but not nitrogen and vitamin B12 concentration, in the Nakasuji River water was found to reach almost the level which can maximize the growth rate of this alga. Growth potential in the water was estimated to be more than 6×103cells/ml from the quotients of those nutrient concentrations divided by each minimum cell quota of the alga. These results suggest that the water of the Nakasuji River has the potential of growing enough algae for the abundance of red tide during the cold seasons.
  • 中山 昭彦, 藤井 建夫, 中尾 マリ
    1990 年 56 巻 2 号 p. 361
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
  • 河原 栄二郎, 大島 俊一郎, 野村 節三
    1990 年 56 巻 2 号 p. 363
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
  • 浜野 かおる, 田村 誠治, 柳沢 忠
    1990 年 56 巻 2 号 p. 365
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
  • 長谷川 英一, 小林 裕, 丹羽 宏
    1990 年 56 巻 2 号 p. 367
    発行日: 1990/02/25
    公開日: 2008/02/29
    ジャーナル フリー
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