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In a previous paper, the authors reported that psychrophilic and halophilic histamine-forming bacteria, which could produce histamine at 5°C, could be isolated from the common mackerel flesh homogenates stored at 5°C and 20°C, these organisms were named “ N-group bacteria ” for the time being. The present study was undertaken to obtain further information as to the occurrence of Ngroup bacteria on/in red meat fist, common mackerel, saury pike, and sardines. These fish samples were allowed to stand at 2.5°C. N-group bacteria occurred on/in all samples; the number of them in the fresh ones were 1 to 102 per gram of the flesh (0.01 to 1% of total bacterial number), while those in the spoiled ones were 106 to 108 (1 to 10%). N-group bacteria seem to occur as a part of the normal surface microflora of marine fish.

The distribution patterns of saury eggs, larvae and early juveniles have been investigated over the continental shelf off the South-Western Cape from August 1977 to August 1978. Young saury tend to occupy water of 18°C or warmer in all seasons and are found offshore of the Benguela oceanic front when inshore upwelling is evident. Their distribution in the region appears to be linked to seasonal hydrography. Spawning in the study area occurs mainly between Cape Columbine and Cape Point, and to a lesser extent east of Cape Point. The ratio of large larvae and early juveniles to small larvae is greater off the West Coast than off the South Coast. Most spawning appears to take place in summer, with a peak abundance of larvae and early juveniles towards the end of this season. Instantaneous natural mortality was calculated: 5 – 30 mm, Z = 0,14·day−1; 30 – 100 mm, Z = 0,02·day−1. There is therefore a marked but unexplained decline in mortality shortly after the transition from the larval to the juvenile phase.

1) The reproductive relations of the large and medium sized fish were examined to investigate a general tendency of population and influence of catch, using total catch in number N1 and number of the immigrants N2 by size category and year given in the previous paper. 2) Relatively independent two cycles (even year cycle and odd year cycle) are considered to exist, as N2 varies every two years. E-R relations by size category and cycle were examined on the basis of the widely recognized subpopulation theory. Here escapement E and return R are represented by the adult spawner (N2-N1) and the recruitment (N2), respectively. 3) Proportional relation between E and R is not significant for each size category and cycle. Reproduction curve of RICKER'S type did not fit significantly to the large sized fish. For the medium sized fish, this application was significant and dependency of R/E upon density was shown. 4) Population for each size category and cycle is reduced by failure of reproduction. In the reproductive aspect, no positive evidence has been given that population is reduced by overfishing. Fluctuations in population are considered to be seriously affected by the reproductive success or failure.

Although the total landings of coastal pelagic fishes around Japan have been fairly stable for 10 years, the catch of individual species has shown violent fluctuations. The catch of Hokkaido herring and the sardine is decreasing and shows no signs of recovery. The catch of saury has also decreased sharply since 1960, but that of mackerel has increased substantially. There are big yearly fluctuations in the landings of squid, horse-mackerel, and anchovy, but no consistent trend either way has been shown. Apparently the great variations in stock abundance relate to the hydrographic complex in the waters around Japan. As most of the important coastal pelagic fishes spawn and spend their early life in the area of the continental shelf of the southern half of the Japanese islands, the location and the strength of the Kuroshio current play an important role in the ever-changing environmental conditions. Although the causes of these fluctuations are largely unknown, they can be classified as long, intermediate and short-term. The large-scale fluctuation over a long term, as in the case of the Hokkaido herring and the sardine, may possibly be due to evacuation of the main spawning grounds. The intermediate period of fluctuation is caused by the degree of survival of the young. A variety of causes must be responsible for the short-term fluctuation, including survival, for which there is no consistent trend, and the effect of the Kuroshio current on the distribution of the young fish.

Muscle Type I collagen of five teleosts was characterized with respect to its thermal stability and subunit composition. The muscle collagen exhibited a higher denaturation temperature, Td, in solution and a higher degree of proline hydroxylation, compared with skin Type I collagen of the respective species. Moreover, the Td values seemed to increase with the increasing upper limit of environmental temperature of fish habitats. The subunit composition also varied with fish species; an α1α2α3 heterotrimer existed in eel and common mackerel and an (α1)2α2 heterotrimer in saury, while (α1)2α2 and α1α2α3 heterotrimers appeared to be major and minor components, respectively, in chum salmon and carp.

1981年9月, 北海道の南東沖合で漁獲されたサンマCololabis sairaに橈脚類Pennella sp.(サンマヒジキムシ, 新称)の寄生が確認された。従来, Pennella属のサンマへの寄生は北米西岸沖合域のものに限られていたため, 1981年と翌1982年の両年にわたり, 北西・中央太平洋とオホーツク海の58点より4588尾のサンマを得て, その寄生状況を調べた。その結果, サンマヒジキムシの寄生を受けたサンマは, これらの海域に広く分布することが判明した。虫体は宿主の筋肉中に体前部を穿入させ, 一対の長い卵嚢を付けた黒色の胴部を宿主の体外に露出させていた。北西太平洋における本種の寄生率は1981年には0.7%と低かったが, 1982年には8.1%と上昇し, 最近, 本種の個体群が増大していることが示唆された。また, 過去の調査でサンマに本種の寄生を認めなかったのは, 寄生率の低さに原因すると考えられた。被寄生魚一尾当りの寄生数は最高6虫体で, 平均1.00～1.32虫体であった。

A four-year study of the feeding habits of six pelagic teleost species in eastern Cape coastal waters of South Africa is analysed. These predators are Lichia amia, Pomatomus sallatrix, Seriola lalandi, Atractoscion aequidens, Katsuwonus pelamis and Thunnus albacares. All species occur in inshore coastal water (< 1 -8 km from shore) for at least part of the year. The tunas were also sampled from the edge of the continental shelf (40–50 km from shore). The use of squid ‘beaks' and fish otoliths allowed accurate prey identification and size estimates. Variations in prey taken are attributed to differences in locality, predator species and size. Three pelagic fish species are important to all the predators: Sardinops ocettata, Etrumeus teres and Engraulis capensis. The inshore squid, Loligo reynaudi, is another major prey item. Offshore tuna samples revealed a different prey spectrum, viz. oceanic squid and saury, Scomberesox saurus, being taken frequently.

Summary Batchelor, A. L. & Ross, G. J. B. 1984. The diet and implications of dietary change of Cape Gannets on Bird Island, Algoa Bay. Ostrich 55:45-63. The diet of the Cape Gannet Sula capensis breeding on Bird Island, Algoa Bay, South Africa, was investigated. Approximately 2000 regurgitations representing 13300 prey items were examined. Twenty-three teleost and two cephalopod species were recorded in the diet. More than 90 % of the numerical composition consisted of the three species Pilchard Sardinops ocellata, Anchovy Engraulis capensis and Saury Scomberesox saurus. The proportions of these three species in the diet changed during the sampling periods. These changes were not related to the implied migration patterns of these species. Chick growth rates were investigated in conjunction with the dietary study. These results indicated that Cape Gannet chicks on a diet of Pilchard and/or Anchovy were more likely to fledge successfully than those on a diet of Stockfish Merluccius capensis or Saury. These ...

1) Selections of life history is examined quantitatively for marine fishes based on mechanical models on survival, growth and maturation. 2) For survival model, usual exponential model is applied and for growth modelvon Bertalanffy growth curve is used. 3) Total assimilation, total egg production, mean duration of generation and equilibrium catch of one year class throughout its life are calculated. Effects on these quantities of manipulating parameters are examined particularly forK ofBertalanffy's growth curve, life spanT and natural mortality coefficientM. 4) Three kinds of strategies are taken into consideration. They are to maximize (1) growth rate of population, (2) energy efficiency for egg production and (3) total egg production throughout the life. 5) Adaptation strategies are considered under the condition of no fishing. Strategists of first kind include anchovy and saury and have largeK andM values and smallT values. Strategiests of second kind include sardine and herring and have large values of allK, M andT. Strategists of third kind include tuna and flatfishes and have smallK andM and largeT values. 6) Referring to tuna, sardine and anchovy, three sets of parameter values are posturated and the effects of fishing are examined. Tuna type fish are most severely affected by fishing but sardine and anchovy type fish are affected moderately or slightly by fishing provided that only adult fish are exploited. Particularly anchovy type fish are considered to be quite tough against fishing. 7) Discussions are presented on such subjects as relation between environment and selection of life history, types of population fluctuation, and fisheries management problems.

A series of experiments on a model of saury blanket net (Bouke-Ami), the scale of which was reduced to 1/52 to the full scale according to TAUTI S principle, were made for the purpose of study the sweeping volume of the net and variations of the shape in the course of lifting when the weight of sinkers, their position, and lifting speed were varied in a still water. The float line of the net was supported by a bamboo float which was fixed at a definite position of water surface by two outriggers, then the lead line was pulled up by the lifting lines. Stroboscopic photographs of lifting movement of the net are shown in Plate 1. According to the results obtained, the sweeping volume of the net seems to be larger with the weight of sinkers, when the lifting speed is kept constan ??, and to be larger with the lifting time when the weight of sinkers and its position are not altered, while the obvious diffrence due to the position of sinkers can not be recognized.

During the months of November and December large schools of the saury, Cololabis saira, would migrate southward along the Pacific coast of Japan, traversing an area extending from Oshima to Miyakejima (islands). However, only small schools of the fish would usually be observed in the south of the latter island except in December 1948 when nearly two metric tons of the fish were hauled off Hachijo Island some 60 miles south of Miyakejima. In an attempt at throwing light upon the exceptional catch on that occasion oceanographic data in the region in December 1948 has been compared with those of the same month of the previous year. In consequence, the Oyashio, a cold current, has been found prevailing in the area in 1948 with a surface isotherm of 20°C, receding as far south as beyond Hachijo island. Whereas, in 1947 that temperature line expanded to the north of the island likely under the in-fluence of the Kuroshio, 2 warm current which was dominating then and there (Fig. 1). The fact is suggestive that numbers of the adult saury on their way of southern migration seem to come over the sea around Hachijo Island only when the isothermal zone of 20°C. has withdrawn south of the island. The length and weight of a few specimens fished in the area are shown in Table 1 together with some relevant data. In the results of spawning surveys of the saury carried out by authors in 1953 and 1954 in the region under study, 276 youngs measuring 65 to 75 mm in total length became available (Table 2, Figs. 2 and 3). On the basis of knowledge thus acquired in regard to the maturity of the adult as well as occurrences of the young it may be asserted that the spawning in the region takes place once a year during November to the following May with February and March as its height: water temperatures suitable for the youngs approximately range from 17 to 23°C. in the spawning area covering from the vicinity of Oshima to Torishima or perhaps more southerly to the Bonin Islands. Particularly the youngs were abundant in the counter Kuroshio current. An assumption derived from these findings, but yet to be proved, is that considerable amounts of the spawners would travel southward to Ki'nansho (bank), while the hatched young running up north along the counter Kuroshio current. A. question as to whether or not the present species would spawn to any extent in summer when then pass the region on their way back to the north is left to be solved.

Two feeding trials with rats were carried out to determine the possible presence of unidentified growth factor in fish solubles or whole meal. In the first test four groups of weanling rats, 3 males and 4 females each, were pair-fed for 6 weeks. To the control group was administered a basal diet containing casein at 15% level and to the comparable groups, test diets in which 15 percent of the amount of casein was replaced isonitrogenously by jack mackerel meat meal, liver solubles and liver meal from bluefin tuna respectively. The results showed that supplement with the two fish materials improved protein efficiency ratio (PER) of females in the latter half period though not in the former half period of feeding. The effect of fish materials was not observed in males during the entire feeding period. The second test was carried out similarly, but two levels of dietary protein, 15 and 8%, were provided and saury fish solubles was used as the sole substitute. At 15% level of protein, supplementing basal diet with the fish solubles had no effect on the growth of rats of both sexes, and this trend was uninfluenced by preventing coprophagy in rat. However, at 8% protein level, the fish solubles improved PER in females by 12 percent as the test period progressed.

It is well known that oxidative deterioration of the lipids in the foods is the cause of the development of off flavors during storage. In the present investigation, the models were used by replacing the food with a support of Celite as a structural component. Beef tallow and saury oil as animal fats, safflower oil, rape oil, soybean oil and cotton-seed oil as plant oils, and stearic acid, oleic acid, linoleic acid and linolenic acid as fatty acids were added into the Celite (model food) respectively. Those were stored under different temperatures (30°, 0° and -20°C) for 12 weeks. The course of the oxidation of oil was observed by determining the TBA value and peroxide value.Subsequently, it was found that the oxidation of saury oil was significantly higher than other oils and that especially in high temperature like 30°C, the oxidation was higher than in lower temperature. Unsaturated fatty acids were unstable even in the low temperature as -20°C. Furthermore, fatty acids of higher degree of unsaturation were oxidized to a great extent.

In order to know about the dynamics of the saury population in the Pacific Ocean off northern Japan, the catch and effort statistics of the saury lift net fishery were analysed. The abundance index and the effective over-all fishing intensity for every 10-day period was calculated, and the yearly and seasonal variations of the available population were examined in relation to the fishing intensity. Although the catch showed a clear trend of decline after 1962, the abundance of the saury population appeared to be maintained until 1967. The fishing intensity was considered to be reduced since the latter half of the 1950's. The seasonal change of the abundance had a general trend, but it varied from year to year. The role of fish-ing intensity in seasonal variation was not clear because the total coefficient of decrease during the season showed apparently negative correlation with the fishing intensity of the season. Certainly immigration and emigration of fish from the fishing ground played an important role in the seasonal variation. Some discussions on the effect of oceanographic conditions, such as the distribution of water masses on the migration of saury, have been given.

Peroxide value and acid value of fats extracted from 23 kinds of foodstuffs were determined. These foodstuffs were marketed in March, June and September.The results obtained were as follows:Some of confections, boiled sardines, smoked squids, hams and shirasu-tsukudani contained a large quantity of oxidized fat, and fried peas, broad beans, peanut butter, doughnut and butter cracker were found to containsmaller quantity of oxidized fat than the above mentioned foodstuffs. Lard, butter and margarine showed the lowest content of oxidized fat, and these foodstuffs were stable against autooxidation.Fats separated from dried fish, such as sardine, saury and horse-mackerel showed high peroxide values, and dried fish marketed in September contained more oxidized fat than those of March or June.

Es wird untersucht, ob Linol- und Linolensaure, deren Vorkommen in den Olen einiger Suswasserfische gesichtet ist, auch in Salzwasserfischolen enthalten sind. Die Versuche werden an Sardinenol und an Makrelenhechtol durchgefuhrt. Die Fraktionierung der Fettsauren erfolgte durch das Harnstoffaddukt-Verfahren, nachfolgende fraktionierte Destillation der Methylester und zweimalige saulenchromatographische Trennung an Silicagel als Adsorptionsmittel. Die Produkte der Hydrierung, der Bromierung und der Ozonolyse der entsprechenden Fraktionen beweisen das Vorhandensein von Linol- und Linolensaure in Sardinenol und in Makrelenhechtol. Ausfuhrlicher experimenteller Teil. Occurrence of Linoleic and Linolenic Acids in the Sardine- and Mackerel- Oils Exhaustive experiments have been carried out to investigate, whether the linoleic and linolenic acids, which had been found to be present in some fresh water fish oils, also occur in the oil of salt water fish. The oils examined are sardine and saury oils. The fractionation of fatty acids has been carried out through the formation of urea addition compounds, subsequent fractional distillation of the methyl esters and repeated separation through adsorption chromatography with silicagel in the adsorption column. The hydrogenation, bromination and ozonolysis of the respective fractions furnish the proof for the presence of linoleic and linolenic acids in sardine and saury oils.

In manufacturing Kamaboko, which is one of the most important and traditional fish products in Japan having fine texture and high elasticity, fish meat is first washed repeatedly to remove fat, coloring matter like blood, and unpleasant smell. It is generally believed that the washing process is also good, in addition to improvement in color and flavour, for in-creasing the jelly forming ability of fish meat. The work under report was carried out to examine the brief on scientific evidence. In the experiments the arrow-tooth flounder and the saury pike were used to sample meat from; one group of meat was washed well and the other was not. These samples were ground with 3% salt with or without 0.2% potassium bromate. Upon cooking the well washed meat was found forming an elastic jelly with a high jelly strength and little expressible water, while the control (unwashed meat) gave an easily crushable brittle jelly. It is known that elasticity of Kamaboko depends both on the presence of network structure of myosins, and on the amount of myosins. It is inferable, therefore, that repeated washing does not only remove water soluble substances and fat from fish meat, but also brings forth a high concentration of myosins, and gives the meat a favorable condition for highly elastic jelly formation. As addition of fat had no distinct effect on increasing the jelly forming power of washed meat (Table 4), removal of fat by washing does not seem to be a cause of improvement in the jelly forming power. A remarkable decrease of the jelly forming ability, on the other hand, was observed when whole water soluble extractives of meat were added to well washed meat. But no effect on the jelly forming ability followed addition of either deproteinized extractives prepared by cooking whole extractives and removing heat coagulable matters, or hydrochloric acid-soluble inorganic constituents of the extractives (Table 5). Therefore, the presence of water soluble proteins seems to inhibit the formation of elastic jelly. From these results, it is concluded that improving effect of washing on the jelly forming ability of fish meat is attributable to; 1) higher concentration of myosins, basic constituents of Kamaboko and 2) removal of water soluble proteins which are supposed to inhibit myosins from forming network structure in the jelly.

A number of quantitative determinations of TMAO have been reported on various fish species of both freshwater and marine origin but very little is known about the comparative aspects of the TMAO content between the ordinary and bloody muscles of fish. The author, therefore, carried out the measurement of TMAO, TMA and DMA in the bloody and ordinary muscle parts of 16 species of fish and the findings are as follows: 1) In the varieties of so-called dark-fleshed fish such as mackerel, sardine, skipjack, etc., the bloody muscles were rich in TMAO content, while in the ordinary muscles the TMAO content was poor and variable. 2) In white-fleshed fish such as seabass, Japanese gurnard and others the TMAO content was much higher in the ordinary muscle than in the bloody muscle. 3) With the exception of saury and gadoid fish, the TMAO-N content in the bloody muscle indicated less variable levels within a range of 20 to 40mg%, among the species of fish tested. 4) In each fish examined, the amount of TMA detected in the bloody muscle was larger than that in the ordinary muscle. 5) Although a very small quantity of DMA was found in the ordinary muscle of some kinds of fish, larger quantities of DMA were always observed in the bloody muscle of all species examined. 6) Formaldehyde was also detected in the bloody muscle whenever DMA was obviously found, and this fact may suggest a possible existence of enzyme(s) capable to form DMA and formaldehyde from TMAO in the bloody muscles of a rather wide variety of fish.

As a first verification of the surmized duality of saury pike stock in Japanese waters, a few results of granographical rearrangement of existing data are presented in the following respects: 1. From HATANAKA's1) data a conclusion was drawn that saury pike forms two scale rings every year, in February and in September each. 2. By estimating the body-length to be reached at the time of scale-ring formation from those measured for saury pike caught in a best season, May (from the Japan Sea), and in October (from the Pacific), respectively, and putting down these two kinds of values for body-length together in a graph constructed with existing data of monthly body-length of saury pike7), a conclusion was arrived at that two different sequences of growth-curves should be assigned to the catches from the Japan Sea and those from the Pacific, respectively (Fig. 4). The duality in stock indicated by this conclusion may be supported by the granographical suggestion of two groups of saury pike, one hatched in a season extending from late spring to summer and the other from late autumn to winter. 3. The duality of saury pike stock were also pointed to about the grains on scale reported by HOTTA2), those on otolith, monthly change of the relationship between body-length and body-weight and the local and seasonal variations in distribution for egg and fry.

A screening of malate dehydrogenase (M D H) isozyme composition of skeletal muscle from two population samples of saury juvenile collected at Suruga By revealed three phenotypes existing in high frequencies. The electrophoretic patterns and the frequency distributions of three types in the samples indicated that the M D H isozymes are dimers formed by random association of two subunits under the control of separate genetic loci, and three types are attributed to two alleles at the B locus of two loci coding for the enzyme. Both of the two samples of juveniles were composed of the three types in a stage of genetic equilibrium with respect to the B alleles, and each appeared to be a group of individuals having a certain genetic structure.

The fishery in Japan, ever since Tokugawa era, has been developed within circulating economy, and transportation of this perishable item has been developed in a commercial scale in accordance with the advance of cities.In this paper the relation between the character of fishing ports and their localities is analysed based on the shipment of saury pikes. Comments are made on the hinterlands of the following three ports: Hachinohe, Shiogama and Choshi in their relation with the Tokyo market and the competition for the same market.1) Amount of fish on landing is the largest at Shiogama. The price of fish becomes higher at the port nearer to the Tokyo market.2) A vivid competition exists between Hachinohe and Shiogama. Hachinohe, with its unfavorable location for the Tokyo market, ships more fish to Osaka and Kobe districts than to Tokyo.3) Hachinohe ships to the Tokyo market only when the amount of fish landed exceeds the amount landed at Shiogama.4) Shipment from Hachinohe can be classified into four types according to the amount of the fish.5) For the shipping to the Tokyo market, no competition is to be seen between Shiogama and Choshi.6) Shipment from Shiogama to the Tokyo market is in proportion to the amount of the fish landed. In the latter half of saury pike season, however, the shipment of this fish to Tokyo market decreases, because at that time shipment of other common fishes increases. Shiogama tries to seekother, markets in Tohoku and Hokkaido districts.7) Choshi, situated in a most favorable location, being closest to Tokyo, has little shipment to Tokyo and much of the product is consumed by the local manufacturing factories. (Chiefly by canning factories.)8) As the output of fishery is very unstable, fish-processing industry is well developed at Choshi, where balanced supply of raw material can be obtained all year round. Canning factories at Choshi buy about half of their raw material from Tokyo and other fishing ports.

The disease of carp, which is characterized by a marked loss of flesh in the back (Fig. 1) and called “Sekoke” disease, has been a serious problem for carp culturists in Japan. Besides muscle dystrophy, loss of appetite, poor growth and high mortality have been observed as symptoms. As the disease was suspected to be a dietary one due to oxidized oil in dried silk-worm pupae used as a main ingredient of feedstuff, the relation between the disease and oxidized oil was examined. Carp fingerlings were kept for about 120 days on the diet containing 10% of the oxidized saury oil (peroxide value 120-150), with or without DL-α-tocopheryl acetate (Table 1). In 60 days, typical signs of the disease appeared in the group receiving the oxidized oil without DL-α-tocopheryl acetate and the rate of ill fish amounted to 56% at the end of the experiment. The pathological examination revealed that the symptoms are quite identical with those observed on the fish in carp farms. The disease was effectively prevented by the addition of DL-α-tocopheryl acetate (50mg/100g diet). Some results of chemical analyses on the test animals are summerized in Tables 2-4. In connection with the feeding test, the turnover of vitamin E in carp was also examined. As seen in Fig. 2, it is very rapid and marked in hepatopancreas, while far less distinct in the muscle.

Aus Sardinenol wurde Eicosatetraensaure, aus Makrelenhechtol Docosapentaen- und -hexaensaure als Methylester isoliert. Auf Grund der Ergebnisse der Ozonolyse kommen den 3 Sauren vermutlich die folgenden Strukturen zu: 5,8,11,14-Eicosatetraensaure, 4,7,10,13,16-Docosapentaensaure und 4,7,10,13,16,19-Docosahexaensaure. On the Occurrence of Eicosatetraenoic, Docosapentaenoic and Docosahexaenoic Acids in Fish oils The authors have isolated eicosatetraenoic acid from sardine oil and docosapentaenoic and docosahexaenoic acids from the saury fish oil in the form of their methyl esters. On the basis of ozonolysis the authors assign the following configuration to these acids: 5,8,11,14-eicosatetraenoic acid; 4,7,10,13,16-docosapentaenoic acid and 4,7,10,13,16,19-docosahexaenoic acid.

Recently, several antioxidant preparations containing some surface active agents have commercially been developed in Japan, which are to be used in fish manufacturing process for keeping the antioxidant as homogenized in curing solution. In the application of these preparations to the protection of marine products from oil oxidation, the authors have devised a practical method they have named “moment dipping method”. This method is very simple, labor-saving and needs no special apparatous. Thus, merely dipping the raw fish in a solution of a comparatively high antioxidant concentration, 0.05 to 0.10%, made by using said antioxidant preparations is effective enough to cause a considerable amount of antioxidant to be fixed on the fish body. In this paper is presented the effect of “moment dipping method” obtained for salted-and-dried fish (saury), the results being as follows: 1) With dried fish having high moisture contents, BHA-preparations were found to be more effective than BHT-preparations, but the difference in efficacy between these two antioxidant preparations was quite small. So, application of the latter preparation, less expensive, is thought to be preferable. 2) On the other hand, with dried fish having low moisture contents, BHA-preparations are far superior to BHT-preparations. So, application of the former preparation seems to be desirable. Since 20% addition of BHT-preparation to BHA-preparation brought no appreciable reduction in efficacy thus in treating well dried fish, the cost of antioxidant addition will slightly but certainly be curtailed by such addition. 3) With dried fish having moisture content whether high or low, the efficacy of “moment dipping method” was found in either case to be slightly inferior to that of the long-time immersing method usually adopted in Japan. The difference may be attributed to the rather small fixation of antioxidant on fish body realized by said new method. So, if an increased amount of antioxidant in immersing solution up to above 0.10% or by increasing the viscosity of the solution by means of some material as, for instance, CMC, a much greater effect is expected to be attained. 4) The amount of antioxidant fixed on fish body calculated from the weight increase taking place in the moment dipping process showed that there is no danger in the “moment dipping method” even when an amount over the usage limit fixed by Japanese Welfare Ministry is used insofar as it is in the range here tested (0.05 to 0.10% as antioxidant concentration).

Seven different α-glycerophosphate dehydrogenase (α-GDH) isozyme patterns were electrophoretically observed in the white muscle cell-lysates of saury, Cololabis saira, from off the North Pacific coast of Japan and the East China Sea. The patterns indicated that they are controlled by four codominant alleles at an autosomal locus. The occurrence of hybrid isozymes in the heterozygotes suggests that the hybrid isozymes as well as other isozymes are of dimeric structure. Additional α-GDH isozymes which are controlled by at least two distinct loci were detected. It was found that a large scale screening of enzyme types for population analysis can be facilitated by the use of cell-lysates produced by thawing the frozen tissue. It is proposed that the dried cell-lysate-soaked filter paper and the tissue block taken in the agglutination test tray be used for population analyses of this kind because of the convenience in transporting and storing a large number of samples.

In this paper, the authors examined the digestibility of fish meal by a physiological method (with rainbow trout) and an artificial method (the pepsin method). Samples of white fish meal (flatfish) and brown fish meal (saury) were treated with or without several kinds of solvents (ether, petrolum ether, acetone, and benzene) separately, and stored in an oven thermostatically controlled at 30±1°C. before the test. The results obtained are as follows: 1) The digestibility of white fish meal for feeding on rainbow trout, as estimated physiologically is so high as about 80 to 85%, while the same of brown meal is about 50%, So, this may be one of reasons for low feed efficiency of the latter meal. Hence this type of meal contains some indigestible state of protein. 2) The digestibility estimated both by the pepsin method and the physiological method differs a little for white meal, having high digestibility, whereas, the corresponding difference is large in case of a brown meal, having low digestibility. 3) Whether in the pepsin method or in the physiological method, digestibility of white fish meal is hardly affected by subjecting it to the solvent extraction, while that of brown meal is somewhat increased by the same treatment.

Sardine, mackerel, saury and similar kinds of fish are processed into salted and dried forms, a favorite item of Japanese diet. However, little attention has been paid to the nutritive value of protein or lipids which are contained in these products. While the nutritive value of proteins of the dried meat is not supposed to decrease in the result of processing or storage, the oils of dried fishes are rapidly autoxidized by the atmospheric oxygen. Therefore, an attempt has been made to examine the nutritive value of oil of salted-dried fishes by animal feeding, from which the following has been found. (1) As shown in Fig. 2, the oil extracted from salted-dried saury (Peroxide Value 65) indicated the toxic effects upon the growth of rats. However, the oil extracted from saury treated with butylated hydroxyanisol (B. H. A.) brought no retarding action to the rats. (2) The oil of salted-dried herring (Peroxide Value 14) had the good effects on the animal regardless whether or not it was treated with B. H. A. (Table 4). (3) The nutritive value of oil of dried mackerel (Peroxide Value 24) was slightly lower than that of B. H. A. treated oil (Table 5). With these findings in mind, it has been concluded that the nutritive value of oils of salted-dried fishes is influenced by degree of autoxidation, and if the original oil shows a high iodine number, the nutritive value becomes lower. However, when the antioxidant is applied to the material fish, the nutritive value remains as good as that of the original oil.

Studies on the relationship between soaking time of bait used in the tuna long line fishery and the breaking power (physical intensity) on it. The results obtained are summarized as follows; 1. The weakening phase caused by the breaking power within 18 hours in the investigation in the sea could not be clearly determined. 2. In the laboratory, the progress of the weakening phase by the breaking power was very slow during the first 10 hours but it proceeded rapidly after 12 hours. 3. The breaking power (tearing saury bait from hook) was more than 840 g-w after 18 hours in the investigation in the sea and more than 640 g-w after 20 hours in the laboratory.

In Japan, saury has been caught by stick held dip net from September to December, in the coastal sea areas of the pacific. The process of the capture of fish with stick held dip net is divided into the following three orders according to the kinds of fishing lights. First of all, saury is gathered to around of starboard being lured by fishing lights which is equipped at starboard. Generally this light is named as gathering light and composed of 13-30 white globes of 500W. Secondly, saury is removed to port side from starboard where fish has been grouping by the action of fish light which is set at port, usually this light is called as guiding light and composed of 3-7 white globes of 500W. Last of all, saury is lured into the net setting in advance into the water with aid of light, usually this light is called as catching light and composed of 3-6 red colour globes of 500W. (These data concerning the composition of fishing lights were supplied from saury fishing boats in Chiba prefecture in 1955) The results of this study will be discribed as follows; Let C is the intensity of illumination in candle power the quantity of saury gathered to starboard is proportionate to C1/2-1/4 of gathering light. When the ratio of the candle power of guiding light to that gathering light is half and less, saury is lured most effectively to port from starboard. The most suitable numbers of catching light to make saury lure into the net is composing 5-6 and less red colour globes.

To study on the spawning condition of the northward migrating saury in adjacent waters to Oki Islands, 25 times horizontal surface hauls with 1.3m, larval net were carried out during the period of main spawning season of the fish from May to June in 1962. And about 5kg. masses of floating seaweeds consisting of those caught with the larval net and those entangled in drift nets from 18 stations, were examined to calculate the number of saury eggs deposited on the weeds. 1) Total number of eggs and larvae collected in the periods of the investigation amounted to 1, 520, 000 and 14, 800 individuals respectively. The number of eggs per lgr. floating seaweeds, to which the eggs attached, varied from 10 to 1, 140, and the average being 388. The number of larvae per haul of larval net was 291. 2) As to the relation between the oceanographical structure and the distributions of eggs and larvae of saury, the following results were obtained. The eggs of the saury were distributed abundantly along the boundary zone between the 2nd branch of the Warm Tsushima Current and the ‘Offshore Low Temperature Region’, (SHIMOMURA and MIYATA, 1952), but the larvae were distributed abundantly in the coastal water region (the 1st branch of the Current).

It was previously observed that the synthetic antioxidants, methylene blue, BHA and ethyl gallate, are all ineffective on muscular dystrophy of carp induced by oxidized saury oil and that methylene blue promotes the disease. Succeeding to the previous work, the effect of DPPD and ethoxyquin was compared with that of DL-α-tocopheryl acetate on the muscular dystrophy of carp and that of methylene blue was reexamined. As shown in Table 3, the both antioxidants, DPPD and ethoxyquin did not counteract the action of oxidized saury oil and the former killed carp in 30-40 days at the level of 250mg%. When kept on a diet containing 120mg% of methylene blue, carp showed a typical sign of the disorder in 7 days and the rate of diseased fish exceeded 90 percent in 20 days. A high blood glucose level was observed in the lots, in which fish showed a high percentage of muscular dystrophy.

During 1955 and 1956 the authors conducted 87 survey cruises for distribution of larval forms of the saury pink, Cololabis saira (Brevoort) in Zu'nan Region extending from Sagami Bay to Torishima (Fig. 1). On the basis of the materials and data made available from the surveys, analyses have been made, in succession to a previous work, in regard to the distribution of the larvae and the length composition of the catch, which may vary depending on locality and year and be related with changes in oceanographical conditions in the region. The number of individuals of the larvae collected at each station is listed in Tables 1 and 2 together with the data pertinent to total length, gear used and so forth. Noticeable features those tables reveal are as follows. 1) Stations in the vicinity of Torishima showed the distribution in a greater density than any other offshore station. 2) In the inner niche of Sagami Bay, where a water boundary exists, about 150 individuals accrued from a single haul of a larval net. 3) Generally speaking, 856 larvae collected with a dip net between Aogashima and Torishima were greater in total length than those obtained at most of larval netting stations. By sorting the samples into several groups according to the locality, time and gear of collection, the total length frequency has been compared among the different groups (Fig. 2). As is evident in Fig. 2, the catches both by dip net and by larval net indicate that the length class where the mode takes place is greater in 1956 than in 1955. Considerable numbers of the larvae measuring about 10 centimeters or less in total length occurred in Sagami Bay and in the neighbourhood of Torishima. Furthermore, 18 adults which occurred off Torishima in early March of 1956 and measured 28.83±1.46cm in body length apparently belonged to a spawning group. These facts suggest that the saury pink spawn substantial quantity of the young in these general localities. According to oceanographical surveys carried out by the R. V. To'nan Maru along a longitudinal line connecting the Izu Islands during the period from 1954 to 1956, the locality of the water boundary between the Kuroshio Current and the littoral waters is moving further offshore one year after another (Fig. 3). Apparently the movement of the water boundary has been dependent on the status of a cold water mass off Enshu Nada. On the other hand, the larval distribution has been nearly twice greater in the Kuroshio Countercurrent area than in the Kuroshio Current area flowing eastwards (Tables 3 and 4). On the basis of these findings it is inferable that a close relation exists between translocation of the major basin of the Kuroshio Current and changes in the spawning conditions of the saury pike and particularly in the length composition of the young whose mode has been found greater one year after another. Frequency of surface temperature at the collecting stations, showed that nearly 75 percent of the stations had the temperature ranging from 18° to 21°C (Table 5).

The amounts of vitamin B6 in the meat of various species of fish were determined by microbiological assay using Saccharomyces carlsbergensis as test organism. From the results shown in Tables 2 and 3 it has been revealed that: 1) The individual differences of vitamin B6content in a unit amount of meat are very little among the same species regardless of size of fish. The fact is suggestive that vitamin B6 would not be accumulated more than a certain amount as it performs an enzymic function and is constantly consumed for the metabolism. 2) In general, the meat of pelagic migratory fish, such as round herring, skipjack, and saury, contains amounts of vitamin B6 far greater than that of sedentary or bottom fish, such as Alaska pollack, rock cod, and Blanquillo. 3) The meat of fresh water fish is poor in the vitamin B6 content in comparison with that of marine fish excepting Alaska pollack, rock cod, and Blanquillo.

The fishing power of saury blanket net (Bouke-Ami) boats based on the fishing ports in Awa-Gun in Chiba prefecture was studied by means ef using daily catch of each boat reported from 97 boats and the results obtained were as follows. 1) The size of net, the number of attraction lump and another elements of boat as shown in Tables 1-4 have no connection with the fishing power of saury blanket net fishery. 2) Through the fishing season, the average catch of 10-29 tons class in the fishing boats are equal to about 60 percent of that of above 30 tons class as shown in Fig. 2.

The region that is contiguous to the Sea of Okhotsk in Hokkaido is a tract of land covering Cape Notsuke, by way of Cape Shiretoko to Cape Soya. In this thesis, however, Wakkanai is also included. There lie three cities, nine towns, and three villages in this region, and about 5, 000 families of fishermen are living depending upon the Sea. 1. STATIONARY FISHING: Salmon and trout fisheries are done in this method, which excel in Shari and in Shibetsu. Especially the fishermen of Utoro in Shari depend upon this stationary fishing, and in the fishing season they move, to Shiretoko Peninsula, to the north of Utoro, to fish. 2. CO-OPERATION FISHING: This is cheifly practised in gathered tangle and catching hairy-crab. The tangle is called Rishiri tangle, and is grown on the rocky shore of Wakkanai and Rausu. As the fishing season approches, in Rausu they move to the northern part of Shiretoko Peninsula hairy-crab pot fishery is practised on a huge continental shelf lying in front of the coast from Tokoro to Hamatombetsu. Omu, Esashi, and Mombetsu excel in their catch because of their convenient location. 3. PERMISSION FISHERY: In this, scallop dredge fishery, saury stick-held dip net fishery, one-boat medium trawl fishery, dog fish drift line fishery are chiefly included. The fishing-places of scllops are the continental shelf off the coast of Kitami and C. Notsuke and its cheif producting districts are Yubetsu, Tokoro, Abashiri, and Esashi. The cheif fishing place of saury stick-held dip net fishery is the offing Mombetsu, and the fishermen sail out fishing from Abashiri and Mombetsu as thier bases. Fishing season being late, the fleets of vessels belonging to the Pacific Ocean also take part in it. One-boat medium trawl fishery is done to catch pollacks, cod, lockingtons, sharks on the huge continental shelf covering off the coast of Tokoro to Sakhalin, and their bases are Abashiri, Mombetsu, Esashi, and Wakkanai. Abashiri and Tokoro excel in dog fish drift line fishery and its fishing-places are near the isobathyic line of 200 metres. But in late autumn sharks being near thes hore and living on the bottom of the sea, they fish with one boat medium trawl fishery. 4. SECTIONAL FISHERY: This is done in gathering oysters in Lake Saroma in under-water method, and gathering immatured scallops. Fishermen depending upon Lake Saroma amount to 320 families. 5. Regional figures of sea products are as follow: one is the large producting district having many kinds of fish and the other is a small producing district having a few kinds of fish. To the former belong Rausu, where maltiple manegement is practised, Abashiri, Mombetsu, Esashi, and Wakkanai, where off-shore fisheries chiefly practised: and to the latter the other regions. 6. The distribution of fishing boats is as follows; (a) region which has a large number of fishingboats, (b) region which has a small number of fishing boats. The former is the region where ships are improved to be large and modernized, and the latter is not. And these agree to each region mentioned in the last section. In short, the fisheries of the coast of the Sea of Okhotsk are, in the eastern parts, coastal fishing based on the base of continental shelf as its fishing place.

Succeeding to the previous work, in which the so-called “Sekoke” disease of carp was shown to be a typical muscle dystrophy due to oxidized oil, the preventive effect of antioxidants, methylene blue, BHA and ethyl gallate, was examined and compared with that of DL-α-tocopheryl acetate. In addition, oxidized saury oil of different peroxide values and acetone-soluble lipids from dried silk-worm pupae were tested. As shown in Tables 1 and 4, these antioxidants except DL-α-tocopheryl acetate are ineffective, although they were reported to alleviate some of disorders induced by oxidized fish oils in terrestial animals. It is also observed that the muscle dystrophy is induced by the oxidized saury oil of a very low peroxide value and also by acetone-soluble lipids from dried silk-worm pupae. This may suggest that peroxide has little connection with the incidence of muscle dystrophy. Results of chemical analyses on the test diets and animals are summarized in Tables 2, 3 and 5.

Foods sealed tightly in cans and various packaging materials, are on the markets and the supervision of these foods is being regarded as serious from the public. Especially, the quality of foods as the source of proteins is important from a view-point of food hygiene. For this reason, it is very desirable to find a method that the quality of meats of aquatic animals is determined quickly and exactly. The staple part of meats of aquatic animals is composed of proteins. Since the proteins, however, are very complicated and highly polymerised compounds, it is difficult to catch minute variations in the structure of the proteins.The polarographic wave of each protein may be particular to the protein itself. Consequently, polarography is a very excellent method in learning the characteristic property of each protein. Since we have wanted for quite some time to use the polarographic method in studies on the quality of foods, we have adopted the polarography in order to confirm the difference of the polarographic behaviors of the proteins in meats of aquatic animals more quickly and exactly than the methods used before.To 1 gram of crushed meat, 100ml of distilled water was added. After centrifugation, various amounts of the supernatant solution were used for the estimation of the polarographic waves of the proteins. The protein waves were estimated in a buffer with the following composition at 25°C: 0.001M·CoCl2, 0.1M·NH4Cl, and 0.2M·NH4OH. Under these conditions, we have examined the influences of the protein concentrations on the protein waves obtained from the water extracts of the meats in the aquatic animals of 85 species. The results of the experiment mentioned above are as follows:From differences in the shapes of their protein waves obtained here, 85 species of the aquatic animals are classified into the following four groups:Group I gives the protein wave that a single protein wave is shown and the second maximum wave is very indistinct. 19 species, such as sardine, mackerel, saurel, saury, etc., belong to this group.Group II gives the protein wave that the height of the second wave is very lower than that of the first wave and the second minimum wave is very low. 25 species, such as sillago, perch, wreath shell, pond smelt, etc., belong to this group.Group III gives the protein wave that the second maximum wave and the second minimum wave are not very low. 32 species, such as flathead, hairtail, clam, scallop, etc., belong to this group.Group IV gives the protein wave that the height of the second wave is higher than that of the first wave. 9 species, such as prawn, abalone, oyster, corbicula, etc., belong to this group.When we use cleverly the crossing points which are obtained from the relation between the heights of the protein waves and the protein concentrations, the qualities in the meats of 85 species of aquatic animals may be discriminated by their protein waves in a certain extent.

The fishing effect of five kinds of ground baits to find economical bait instead of salted anchovy lavae which is commonly used for bait in bonit trolling were tested under the procedure comparing the number of catch by using both anchovy lavae and ground bait alter-natively in the sea at five minute's intervals by the boat, 4 tonnage, 16 horse power with two crews. The results are shown as in Table 1 and Figure 2 that small shrimp (Acetes japanicus), herring (Storephorus japonicus) and sand lance (Ammodytes Personates Girad) are comparati-vely good in the fishing for bait, saury bait fluctuated in the fishing and mixed bait anchovy with noodle is a bait of less merit comparing with normal bait. The effect for bait largely depends upon the sinking speed of bait which is cleared as shown in Fig. 1. The examination in the contents of stmach of bonito caught clearly shows that forty percents of fishes eat experimental ground baits and especially in the afternoon twenty percents of fishes eat ordinaly bait given by other commercial boats at the bonito trolling, shown in Tables 3 and 4.

Examining the graphic representations of body-length distribution by KIMURA3) for catches of saury pike, it was noticed a peculiar situation that in fishing seasons extending every year from September to December, during which the fish continues to increase in body-length, the values for the most predominant body-length characteristic of every mode of body-length distribution changes in some cases suddenly from a route to another and in other cases stepwise from a higher level to a lower (see Fig. 1). In the light of the relationship found between body-length and time of scale-ring formation or granographically assessed age of saury pike, which is now in preparation to be published, the abovementioned peculiar phenomena about body-length distribution were interpreted as a reflection of that any school of saury pike is possible to be replaced by or mingled with that of another age. As to the fishing ground where such replacing or mixing is realized, its yearly change in geographic position seems to be negligible. It may be regarded, therefore, that a school of saury pike temporarily form separate schools on the way of their migration toward the north and the south along the coast of Japan proper.

Changes in the population size and geographical distribution of the mesoparasitic copepod Pennella sp. (Siphonostomatoida: Pennellidae) on the saury, Cololabis saira, were studied for a period of six years (1981–86) in the western North Pacific Ocean and adjacent seas. The parasite was first recorded in the western North Pacific in 1981. Its population size increased rapidly in 1982–83 and declined slightly in 1984. During these years, infected fish were widely distributed in the western and central North Pacific and also found in the Sea of Okhotsk and the Sea of Japan. However, the population declined dramatically in 1985 and its distributional range was reduced. The parasite disappeared in 1986. The observed frequency distributions of parasites on the host population were the Poisson in 1981 and 1985, but those during 1982–1984 were over-dispersed and fitted the negative binomial.