The settling volume of the net samples which were collected in the years 1950 to 1953 in the open sea south of Shionomisaki tip shows the maximum in spring and minimum in autumn.
The annual mean of settling volume is largest in the coastal area and decreases gradually toward 31°30'N. It increases again around 30°30'N and reaches its minimum at the Ocean Weather Station T(29°N, 135°E). This tendency of fluctuation seemed to be agreeably corre-sponding to the distributional pattern of the Kuroshio current and its counter current.

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Few species of fishes have greater, amounts of landings here in Japan than the flying squid, Ommastrephes sloani pacificus, as they are fished almost in all the coastal wa ?? crs throughout the year. In the area neighboring to the Oki Islands on the sea of Japan, the majority of the catch are produced by fixed netting in colder seasons of the year.
On the basis of these facts an attempt has been made to explain statistically the relationship between fluctuation in the catch and meteorological factors such as the low pressure, discontinuity, wind and the atmospheric temperature. The period under study covers every fixed netting season from October 1950 to March 1954.
1) The hauling seems to decrease for a day or two after the low pressure most closely-approached to the fixed netting grounds. Whereas no significa ?? difference in the effect of the low pressure on the catch is evident for either the days imm ?? diatcly before or on the third day after the encounter of low presure (Table 1).
2) On a morning followed the windy night blowing harder than 7 in Beaufort's scale, the catch would be affected almost with no regard to the direction of the wi ?? d. When it had blown southeasterly or southwesterly, the haul in the next morning increased a little possibly because of a meteorological condition always preceding those blowing weathers (Table 3).
3) An increase in the catch followed the night when the atmospheric temperature had gone down more than 3°C (Table 5).
4) The approaching discontinuity can be said r ?? ponsible for bringing about a greater amount of the squid to be caught in the area under review. Because the favorable conditions for the netting such as the ES or SW wind, or changes in the temperature, are phenomena associated with the discontinuity passing over the area. However, it is necessary for a good haul to have the wind blowing at less than 5 mp ?? on the average (Table 2).

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The rings of otolith were examined in age determination of the one form of the Japanese makerels, Scomber japonicus japonicus (H_OUTTUYN), because the scales are almost completely rubbed off prior to the collecting of the fish.
1) The percents of the otoliths which show opaque or translucent margin for each month of the year are shown in table 2.
2) The relation between the fork length and otolith length is given by F.L=17.7R-9.1 (when F.L is fork length in cm, R is distan ?? between the center of otolith and its anterior margin in mm)
3) The range and average of the fork length of each age group and the calculated fork length are shown in tables 3 and 4.

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There are excellent harvesting grounds of “Chosen-hamaguri”, Meretrix lamarckii, along the open coast of Miyazaki Prefecture. Shells of this clam are used to make the white “stones” used in the popular Japanese game of “Go”, and the meat is greatly desired as food in the district. A study was made during 1903-1955 on some aspects of the biology of this clam, viz. habitat, spawning season, growth, movement and others. The results are summarized as follows:
1) This clam prefers the ocean water and is found on the sandy bottom in the water depths ranging from low tide mark down to 10 meters or more.
2) In the waters off Hyuga City, the spawning takes place between late July and late September.
3) The growth was estimated by Petersen's methed with the following results: at the age of one year, 0.66±0.03cm. in shell length, at two years, 3.43±0.07cm.; and at three years, 5.07±0.07cm. About 9.8cm. is the maximum shell length usually encountered in this district.
4) Marking experiment was conducted for the purposes of clarifying the local movement of the clam and verifying the above-mentioned estimate of growth. As the mark, several spots were engraved with the electric drill on the surface of one of the shells of each clam. The number of these spots, in combination with whether they were engraved on the right or left shell, was to denote the size of the clam at the time of marking. 14912 clams were marked by this method and released on May 15-23 and November 7-9 in 1953, and 294 of them were recaptured until February, 1955. The result of this experiment indicates that the clam scatters, with the increase in age, toward off-shore and also northward along, the coast. It was also shown that the foregoing estimate of growth was appropriate.
5) The relation between length and weight of shell was examined on the materials collected from two areas, off Hyuga City and Kitauramura, and the results for the two samples, were compared, as shown in Fig. 6.
6) The shell of this clam shows on the umbonal region a pattern called the “umbonal mark” which consists of two short radial lines of dark colour (Fig. 7). This pattern is characteristic of this clam, and is not found in Meretrix meretrix lusoria.

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It is said that the autumnal appearance or settlement of the spores of the laver (Porphyra tenera) are greatly affected by the hydrographical or atmospheric conditions. With a view to resolve this problem following experiments and observations were made for four years from 1951 to 1954 in Ise Bay.
1) Daily collection and enumeration of the spores floating in the sea, from late September till early October.
2) Setting the bamboo twigs daily in the sea for about a month from late September and enumerating the germlings appeared on them, ten days after setting up the twigs.
3) Daily measuring the variation in the vertical distribution of the temperature and chlorinity of sea water at various depths in about 1-2 metres interval from the surface to the bottom up to a depth of 6 meters at high tide. In the meantime, the diurnal mean range of tides was computed from the records of Nagoya Harbour as obtained by the tide gauge.
As a result obtained from the above experiments and observations, it is suggested that the spores of the laver are apt to get afloat in large masses for one to five days after the occurrence of such vertical turbulance in the sea water as those which might have been raised by wind or tidal movement.

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In the previous paper, it has been reported that the population of sulfate-reducing bacieria in the bottom mud and the sulfides content of the bottom mud were directly correlated with the concentration of utilizable organic matter in the mud.
In the present study, the authors attempted the experiments concerning the nitrogen requirement of marine sulfate reducers, with the aim of elucidating the relation between the organic matter and the bacterial production of sulfides in the mud.
1) In order to determine the source of nitrogen available to these organisms, various organic and inonganic nitrogenous compounds were tested using the basal medium (Medium 3).
The results obtained are given in Tables 1 and 2 and may be summarized as follows:
(a) In the case of the pure cultule, these organisms could grow Well in the medium containing the complex organic nitrogenous compounds such as pcptone, but could not in the medium containing a kind of simple nitrogenous compounds, such as inorganic salts or amino acids, as a sole source of nitrogen.
(b) In the case of the crude culture, these organisms could grow in the medium containing a variety of organic and inorganic nitrogenous compounds tested, excepting KNO₃, KNO₂, L-aspartic acid, and L-cystcinc.
From these results, the marine sulfate-reducing bacteria seem to require necessarily the complex organic nitrogenous compounds such as peptone for the growth. In the case of crude culture, it must be considered that the complex nitrogenous compounds produced by the action of the coexistent bacteria were utilized for the growth of the marine sulfate-reducing bacteria.
2) The growth response of marine sulfate-reducing bacteria to varying concentrations of peptone which was added, as a sole source of nitrogen, to the basal medium (Medium 3) was studied.
The results obtained are as shown in Tables 3 and 4. These results indicate that in the case of the pure culture, the marine sulfate-reducing bacteria could develop in the presence of very minute quantities of peptone (about 1×10^-8g./L.) and that although the peptone was the essential nutriment for the growth, it could be replaced by the small amount of the preculture of these organisms (about 2 loops per 7 cc.).
These results probably suggest that the peptone and the preculture may be utilized for the growth of these organisms as the source of the accessory growth factors rather than as the nitrogen source.
3) When peptone was provided for the growth of marine sulfate-reducing bacteria as sources of both nitrogen and carbon, these organisms could not grow when the concentrations of pep-tone were lower than 0.1g. per litter (Table 5).
This result suggests that the marine sulfate-reducing bacteria must require extraordanarily higher concentrations in carbon source than in nitrogen source for the growth.
From the above mentioned facts, it is considered that in the bottom mud of the sea an important factor limitting the multiplcation and the activity of sulfate-reducing bacteria is the concentration of the organic matter which can be utilized as the carbon source for the growth of these bacteria, but not the concentration of the organic matter as the source of nitrogen.

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We have previously shown that the marine sulfate-reducing bacteria required extraordinarily higher concentrations in the carbon (energy) source than in the nitrogen source for their growth.
The present study is concerned with the energy sources which are required for the growth of these bacteria.
1) As given in Fig. 1, the activity of these bacteria growing in the medium which was defficient in the energy source was vigorously accerelated by the addition of Ca-lactate (1 g./L.).
2) As shown in Table 1, in the case of the pure culture, the marine sulfate-reducing bacteria could not utilize all of the organic compounds tested (excepting lactate, pyruvate, glycerol, DL-alanine, and formate), as the energy sources for their growth, and in the case of the crude culture, however, these organisms could utilize most kinds of the organic compounds. In the latter case, it is considered that, by the action of coexistent bacteria, a large variety of organic compounds tested were partially transformed into the matters having the chemical natures which could be utilized by the marine sulfate-reducing bacteria.
3) As shown in Table 2, these bacteria could develop by obtaining their energy requirements from the oxidation of molecular hydrogen.

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In the previous paper it was reported that the contents of iron and a kind of carotenoid-vio-laxanthin, were low in the eggs sampled from poor hatching broods.
The present work was carried out to see if a similar relation held also for the samples of another source. The samples were supplied from the Fuji Trout Hatchery together with the data. of thier hatching rates (Table 1). A part of the eggs of each sample was analyzed of thier chemical composition immediately after fertilization, while the remainders were reared at the Hatchery to observe the developing process.
Also for the present samples, the content of iron was found to be proportional to the hatching rates (Table 2). There is a tendency that vitamin B₂ content in the eggs of high hatching, rate is slightly larger than those of low hatching rate (Table 4.).
It should be noted that the yellow pigment in the present samples seems to be different from the one previously reported (violaxanthin), and that the amount of the pigment in the eggs is likely independent of the hatching rate (Tables 3, 4).

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The composition of the egg fat of shark (Squaius sucklii (G_IRARD)) was studied.
The mixed fatty acids were found to consist approximately of myristic acid 3%, palmitic acid 10%, stearic acid 7%, arachidic acid 4%, zoomaric acid 13%, oleic acid 21%, C₂₀H₃₈O₂ 10%, C₂₂H₄₂O₂ 5%, linolenic acid 5%, C₂₀H₃₂O₂ 10%, C₂₂H₃₄O₂ 10% and a small quantity of C₂₁H₃₈O₂.
The unsaponifiable material was obtained as 12.5% of the total fat, and cholesterol, chimyl alcohol, and batyl alcohol were identified. Also the presence of unsaturated alcohols which consisted mainly of selachyl alcohol was supposed.

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The authors propose in this papar a procedure to apply some sorts of antioxidant to salting of salmon. The fish processed thus along a definite direction were examined organoleptically after storage for 3 to 6 months. Some chemical properties of the oil extracted from the processed fish were also examined.
The salt for the processing was prepared as follows: antioxidants such as butylated hydroxy-anisole (B. H. A), ethyl protocatechuate (E. P.), and propyl gallate (P. G.) were diluted with common salt respectively up to various concentrations properly specified after the previous studies¹⁾²⁾.
With the case of B. H. A., the results of preservation experiment were found to be almost satisfactory. However, E. P. and P. G. being less effective as compared with B. H. A., developed a reddish brown off-colour especially in the abdominal part of the products.

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In the present work the spectrum and the mode of action of the antibiotic autoxidizcd calamary oil and the reversal of inhibitory action of it were investigated, and the following results were obtained.
1) The autoxidized calamary oil inhibits the growth of bacteria independently of their Gramstaining characters, and it shows weak antibiotic activity on molds and some strains of yeasts and Fungi imperfecti.
2) The antibiotic action of the autoxidized calamary oil causes the prolongation of the lag period and is effective when added at the beginning of culture, while the autoxidized calamary oil stimulates the growth of organisms in certain cases when added at the stationary period.
3) The antibiotic action of the autoxidized calamary oil is not reversed by sulfhydryl compouds and surface active substances such as cholesterol, lecithin and α-tocopherol; but it is reversed by unsaponifiable matter of plant oil, medicinal yeast and among tested adsorbents only by activated charcoal.
4) It seemed that the antibiotic action of the autoxidized calamasy oil depended on an oxidative product, whose mode of action differed from those of unsaturated fatty acids, saturated fatty acids and surface active substances.

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In the present work, the stability of the antibiotic autoxidized fish oils and the fractionation of an antibiotic substance have been studied, and the following results were obtained.
1) The antibiotic autoxidized fish oils are not stable to thermal treatment by which further oxidation is promoted. They are also unstable to alkaline treatment, but stable to ultraviolet radiation.
2) An antibiotic substance could not be fractiona ?? d by the vacuum or steam distillation. The urea segregation has been found to be a useful technique for the fractionation of it.
3) An antibiotic substance, contained in autoxidized fatty acids or methyl esters derived from shark liver oils, was concentrated into petroleum ether soluble fraction which do dot form urea complex. Further purification was carried out by chromatography using activated charcoal and petroleum ether.

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A considerable effectiveness in prolonging the storage life of the fish fillets has been obtained by a minute dip in minimal concentration of chlortetracycline^{1, 2)}. However, no effectiveness for the shrimp has been observed at the concentraton used²⁾.
The present study shows that at least a 30-minute immersion in a 5% brine containing 10-20 ppm chlortetracycline is needed for a definite preservative effect on the sardine (Table 1). It has been found that the effectiveness on the keeping quality was increased a little with the increase in the concentration of the antibiotics (Table 2). It is of noteworthy that the brine in which the sardine was immersed was spoiled after one day, whereas the brine with chlortetracycline was judged still passable three days following a dip treatment of the sardine (Table 3). It has also been shown that a 10 ppm solution of chlortetracycline was able to treat the sardine at least by the same amount as its volume without any decrease in the effectiveness (Table 4). An overnight stowage of the sardine in coarsely cracked ice containing 10-20 ppm chlortetracycline followed by a storage at 4-8°C. without the ice has been found effective to prolong the storage life of the sardine as judged organoleptically or by the volatile base-N value (Table 5).

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For explanation of the facts that the histamine is usually produced in large amount in mackerel and in less amount in yellow-tail in the course of putrefaction, we have studied the putrefactive process of the normal and autolysed fishes.
The results are as follows:
(1) In the yellow-tail, there has been found little difference in the amount of putrefactive substances in both normal and autolysed fishes. But a larger amount of histamine has been found to be produced in an experiment with autolysed fish. (2) In the makerel, the volatile base and histamine has been produced in a larger amount in the autolysed lot than the normal one.
We have assumed, from these facts, the existence of histidine in higher concentration in inner parts of cells than in the intercellular spaces, and the difference in firmness of cell-walls between these fishes. In the yellow-tail having firmer cell-walls through that the histidine may difficulty exude, the histidine should be hardly attacked by bacteria.

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The starfish, Asterias amurensis Lütken, propagated suddenly in Tokoy Bay, from October 1953 to March 1954, and gave severe damage to the clam culture. Since that time, our attention has been directed to the possibilities of utilization of this species or others of Asteroid for feed-stuffs, not only on account of its abundance but because it must be exterminated, if possible, in order to protect the clam from the starfish attacks.
As the starfish contains much more calcium than fish, it is necessary to exclude the greater part of the calcium from starfish for the purpose of preparing feed-stuffs rich in pro- tein (Tables 2, 3). We attempt to separate the calcium from starfish by digesting it by protease.
The protease process ?? adopted was as follows;
To 1 part of raw stasfish is added 1 part of water and 0.02 part of a commercial bacterium protease “Bioprase, ”^* and the mixture is warmed to 50 ?? 55°C for 1 ?? 2 hours while continuously stirred. Owing to this enzymic digestion, the body wall of starfish is crushed to white pieces of calcium carbonate and precipitated (Table 5; Figs. 1, 2). The precipitated calcium is filtered. The filtrate contains favourably small amount of calcium and considerable amount of various vitamins (Table 6). In place of “Bioprase”, animal internal organ, e.g. liver of blue crab can be used for the starfish digestion (Table 7). The filtrate (the starfish solubles) is evaporated in an open iron pot until the moisture is less than 50 per cent. In the condensation of starfish solubles, the loss of vitamins are very little (Table 8).
That the concentrated starfish solubles has no toxicity is proved by feeding experiment with rats (Tables 10, 11, 12; Fig. 3).

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Many halophilic or halotolerant bacteria were isolated from various kinds of “Shiokara” and 18 sp ?? cies were identified as listed in Table 1. Some strains of halophilic group are shown in Table 2, being identified from the results of their growth-test in high salt media.
On the basis of some inoculation-tests the author concluded that Micrococcus is mainly responsible for the ripening of “Shiokara”, and halophilic Vibrio and Achromobacter are the promoters of spoilage, whereas Bacillus plays no important role in the ripening process.

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As most of the methods for determination of fish muscle proteins are more or less tedious, a more convenient m ?? th ?? d has been desired. The S_NOW's method (1950)⁴⁾which was followed at first by the authors revealed that the linearity between light absorption and protein concentration did not hold for protein concentration beyond 0.3mg. N/ml., and that the formation of turbidity often disturbed the measurement (Fig. 1 Curve-A). Thence a reagent proposed by S_OLS (1947)⁵⁾ was examined. By use of this reagent, the constancy of the absorption increment was kept up to 0.4mg. N/ml. (Fig. 1, Curve B). As for turbidity it was observed that the turbidty increased as a function of time after combining the sample solution and the reagent, and that the turbidity could be removed by centrifuging or filtration (Fig 3). Thus the method was defined as below.
The reagent, which is composed of 0.4% CuSO₄5H₂O, 8% NaOH and 0.2% glycerol, is added to an equal volume of the sample solution, and mixed. After standing for from 3 hours to overnight the mixture is centrifuged for 10-15 minutes by 3, 000 r.p.m. or filtered with no. 3 glass-filter. The optical density of the supernatant or the filtrate is evaluated at the wavelength cf 545mμ, and protein concentration is calculated by the aid of a coefficient determined previously (Table 1). The standard error of the analysis was as low as ±1.98%.
When it was ?? ceded to obtain a rough measure of a protein concentration as quickly as possible, and also in the expen ?? of the accuracy, the authors took advantage of the S_NOW's method in which the measurement is performed between 25-40 minutes after combining the sample and the reagent and without removing turbidity.

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