Plankton were sampled at 17 stations by two types of nets in the Yellow and the East China Seas in June, 1956. The covered area was divided into 4 by plankton distribution and oceanographic features: The 1st area where the cold waters from the Yellow Sea prevail and Euphausia pacifica is abundant, the 2nd area where the cold waters and the coastal ones mingle and plankton show a successive figure, the 3rd area where the coastal waters from the Yantsu River prevail and Sagitta spp., Leptochela aculeocaudata, and microcopepods are abundant, and the 4th area where the Kuroshio Current bears its powerful influence and plankton show a very different figure from those of the other areas, both quantitatively and qualitatively.
As to distribution of plankton species, Leptochela aculeocaudata PAULSON is reported for the first time from these sea areas which has been reported from the Indian Sea, the Red Sea, and Tokyo Bay in Japan¹⁴⁾.

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1) A study on the food habit of the abalone, Haliotis discus hannai Ino, an industrially important gastropod in northern Japan, has been made by feeding it with 7 species of brownalgae, 2 species of green-algae, 3 species of red-algae, and diatom.
2) It has been clarified that brownalgae such as Undaria pinnatifida, Laminaria religiosa, Colpomenia bullosa are the most suitable food for H. discus hannai in respect to its growth and the efficiency of its food conversion. Green-algae, Ulva pertusa and Enteromorpha linza come next in the food value. Red-algae such as Pachymenia sp., Rhodoglossum pulcherum, Carpopeltis affnis etc. and brown-algae, Sargassum fulvellum are inferior in value as food for H. discus hannai. Melobesiae has also been found effective in the shell formation of the adult shellfish.
3) Diatom such as Melosira borealis or Navicula sp. has been found to be a suitable food even to adult abalones and they grow sufficiently well with this food alone.
4) When 2 species of algae are simultaneously given to abalones, they prefer Ulva pertusa to C. afinis, and Undaria pinnatifida to Ulva pertusa, showing some likes and dislikes. Generally speaking, when a mixed food is given to abalones, their growth are inferior to the growth of abalone, fed with algae which are superior as food.
5) It has been assumed that the optimum temperature for the growth of H. discus hannai is within the range of 15-20°C.
6) The efficiency of food conversion at the water temperature of 10.5°C has been found to be 5-8% (12-21% in calorie equivalence) for abalones of 20-30g in weight fed with Undaria pinnatifida and 9-11% (24-29 cal. %) for ones of 60-90g in weight, and the case fed with Pachymenia sp. shows 8-13% (7-11 cal.%) and 22-31% (20-28 cal.%) respectively, and in either case large sized abalones have shown higher rates, but the rates secured the stability at least between 50-100g in body weight.
7) For maintaining the body weight of abalones, necessary daily rates of feeding with U. pinnatifida are 1.75% (0.42% in calorie equivalence) and 0.65 (0.15 cal.%) respectively, for the ones of 20-30g and the ones of 60-90g in weight, and in the case fed with Pachymenia sp. 0.82%1 (0.53 cal.%) and 0.08% (0.05 cal.%) respectively. These rates are smaller for the larger sized abalones.
8) The relation between the species of food and the maturation of gonad of abalones is in exact conformity with the relation between the species of food and the growth rate of abalones, and the food suitable for the growth of the shell also brings a good result to the maturation of gonad.
9) No significant difference in the chemical composition of the meat of abalones due to the species of food has been found, but it has been found that the content of glycogen is greater in those fed with U. pinnatifida or L. religiosa than those fed with other foods.
10) When H. discus hannai are fed with brown-algae, green-algae and diatom, they form a shell of bluish-green color. On the other hand, when they took red-algae, brown colored shells resulted without exception. When they are fed with brown-algae and red-algae alternately, the shells turn into bluish-green color and brown color alternately.

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In the abalone, Haliotis discus hannai Ino, growing ground Onagawa Bay, Miyagi Prefecture, a proportion of the bluish-green area to the whole shell surface may be assumed as an index to the relative growth of the univalve. In this respect the author (1962) experimentally proved that the abalones fed with brown algae grow faster than those given green or red algae, and their shell bears bluish-green color. He (1958) also reported that correlation exists between annual harvests of the abalones and their favorite food, Undaria pinnatifida, a brown seaweed.
The present work was undertaken to evaluate various localities around the Bay for propagation of the abalone by observing the ratio of the bluish-green area to the whole shell surface of the sample specimens and algal vegetation in these areas (Table 1 and Fig. 1). The survey indicated that 1) the annual harvest of U. pinnatifida per kilometer of the coast line was different from place to place (Fig. 1); 2) where the brown alga was more abundant, the abalone grew faster with the bluish-green shell area being larger, than in specimens from the other localities (Fig. 2); 3) even among the specimens from the same seaweed ground, those which had a higher ratio of the bluish-green area grew faster than the others (Fig. 3).
These findings suggest that in a locality where U. pinnatifida is flourish, the abalone oftener eats this seaweed, grows faster, and comes to bear the bluish-green shell area at a higher ratio. In other words, the shell complexion of the abalone from a locality may reveal, to some extent, whether or not the locality is suitable for propagation of the univalve.

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Off Chiba and Ibaraki Prefectures, major fishing grounds for the Japanese anchovy, Engraulis japonica (HOUTTUYN), are located in the waters along Kujûkuri Hama and Kashima Nada. In the area, the fishing activities are concentrated in two seasons of the year, January to July for II-age fish and October to December for 0-age fish. For a period from 1949 to 1960, the prefectural catch from a year class in one of the two seasons is highly correlated with the other, and with the catch of shirasu in Shizuoka, Aichi and Mie Prefectures.
On the basis of these correlations, formulae are given for predicting the catches of 0-and II-age fish in several months or two years prior to the fishing seasons. Application of the formulae to the past data showed that the predicted amount agreed with the actual catch for eight or nine years out of ten. In order to advance the techniques of prediction, studies should be conducted on the following three subjects: 1) compositions of the commercial catch in regard of spawning ground and season, 2) preference of fishermen on a species to another, and 3) environmental effects on distribution of the fish.

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Changes in the contents of various minerals have been followed during the development of rainbow trout, Salmo gairdnerii irideus. The wet weight of 100 eggs increased after fertilization by absorbing water and then decreased gradually as development proceeded. After hatching of the eggs the wet weight increased rapidly (Table 1). The percentages of sodium, potassium, silicon, calcium, and copper on dry basis increased after hatching (Table 2).
As an individual egg changes in its wet weight during development, it is not correct to consider that the contents of various minerals expressed as percentages on dry basis indicate the exact changes taking place within the egg. Thus the changes in weights of minerals in 100 eggs were caluclated. As shown in Table 3, the contents of sodium, potassium, silicon, calcium, and copper increased after hatching out, among them sodium, potassium, and silicon being more remarkable, whereas phosphorus showed rather little increase and magnesium decreased more or less in larval fish.

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From the viewpoint of opening the use of residual oil brought forth in preparing a concentrated product of vitamin A by molecular distillation, a few investigations were advanced into the technique of obtaining from molecular distillation residue of dogfish liver oil a concentrated preparation of glyceryl ether as well as into the surface-active properties of the preparation thus obtained.
In the first part of the present work, a sample of dogfish liver oil as starting material was hydrolyzed by following the routine saponification procedure, unsaponifiable matters were separated and these matters were then collectively submitted to molecular distillation (see Table 1). From the sum of distillate fractions 2, 3 and 4, there was thus obtained through the trial of taking out glyceryl ether from said kind of residual oil in which the ether had been known to be present as resistive to molecular distillation a concentrated preparation of glyceryl ether containing selachyl alcohol as main constituent and having an acetyl value of 246-257.6 and an iodine value of 82.1-87.9 with an yield of 5.36% based upon the amount of starting material. Then, by hydrogenating the preparation of glyceryl ether and recrystallizing the hydrogenation product in ethyl ether, a refined preparation as fine crystals was obtained, which had a melting point of 67.5°C and was proved by elemental analysis to contain C of 73.28% and H of 12.71%. These data may be looked upon to be in a close approximation to those for batyl alcohol appearing in literature.
In the second part of the present work, measuring the interfacial tension between a kerosene solution of the concentrated preparation of selachyl alcohol and water (see Table 6 and Figs. I and 2), said preparation obtained as above from a molecular distillation residue of dogfish liver oil was examined in its aspect of surface-activity (see Tables 2, 3, 4 and 5). As seen from the values thus obtained, the interfacil tension between kerosene and water is strongly minimized by adding the former with selachyl alcohol as said type of concentrated preparation in an amount of 0.25-1%. It was found also that, with kerosene solution containing said preparation in amounts not in excess of 1%, selachyl alcohol exerts the greater ability of lowering the interfacil tension between kerosene and water at the lower temperature, insofar as the temperature concerned is in the range of 20-60°C. Further, to estimate the emulsifying power of said concentrated preparation of selachyl alcohol, two similar series of samples were prepared, which consisted of refined coconut oil added with said selachyl alcohol preparation, on the one hand, and mono fatty acid glyceryl ester, on the other, up to various concentrations ranging from 0.5 to 4%, and these samples were compared with one another in respect of the emulsifying effect they developed in water. According to the result obtained (see Table 7), the two substances examined were both found to be fairly good in emulsifying power. As to the state of emulsion they produce, however, these substances used as emulsifyer were observed to behave somewhat differently from each other. Thus, when the breakdown of emulsion commences, while the emulsion prepared with mono fatty acid glyceryl ester begins to separate an aqueous layer, that prepared with the concentrated preparation of selachyl alcohol does so an oily layer.

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Reduced viscosities of Funori extractive, the water-soluble extractive from the red sea weed Gloiopettis tenax, in aqueous potassium chloride were measured at 30°C. as a function of Funori concentration C and KCl concentration x. The family of η_sp/C vs. C curves obtained for different x was essentially similar to that which had been reported for many other polyelectrolytes. From comparison with data for agar-agar some evidence was obtained which indicates the Funori molecule to have a higher charge density than the agar-agar molecule. A parameter, m, in the PALS-HERMANS method of iso-ionic dilution was found to have a value less than unity, which may be attributed to a binding of counterions to the oppositely charged polyion.

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In the former papers^1-5), studies have been carried out on the polarographically reducible and ultraviolet light-absorbing base (abbreviated as PRB) which is peculiar to the muscle or tissues of mollusca and crustacea. In this experiment, isolation of the PRB was tried from the extracts of dried squid muscle. The fraction precipitable with phosphotungstic acid from the above extracts was chromatographed on a cation exchanger column by the method described in the former papers^{4, 5)}. Other bases and amino acids were removed by adsorbing the PRB with active charcoal or by precipitating with ammoniumreineckate or alcoholic saturated picric acid solution (in Figs. 1, 2 and 3; in Table 3).
The PRB was positive in DRAGENDORFF's reaction (in Table 1).
Then, the PRB was compared with commercial specimens of trigonelline (N-methyl nicotinic acid betaine, an isomer of homarine), purines or pyrimidines, nucleosides and 5-hydroxy tryptamine⁴⁾ by paperchromatographic technique (in Table 2), to show the R_ƒ values roughly resembling to those of trigonelline. The melting point of the PRB chloraurate was 188-189°C. Thus, the PRB seemed to be homarine (N-methyl picolinic acid betaine) isolated for the first time from lobster by HOPPE-SEYLER^{8, 9)}.

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Succeeding to the experiment in the previous paper¹⁾, comparative studies were carried out on the following attempt to establish that the PRB (polarographically reducible base) isolated from the extracts of dried squid muscle is homarine (N-methyl picolinic acid betaine):
1. PRB-HCl derived from its chloraurate.
2. Synthetic homarine•HCl prepared by the methylation of picolinic acid.
3. Trigonelline, a commercial specimen (N-methyl nicotinic acid betaine, an isomer of homarine).
The comparison of the PRB-HCl was made with synthetic homarine•HCl and trigonelline in regard of their absorption spectra, half wave potentials and paperchromatographic behaviors (Tables 1-3 and Figs. 1-4).
The result showed that the PRB-HCl and the synthetic homarine•HCl are intirely same m these properties.
Also, as the results of elementary analysis of the PRB-chloraurate (in Table 4), the PRB isolated from the extracts of dried muscle was identified as homarine.

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In the present work antioxigenic and synergistic effect of Na-erythorbate on BHA which is applied to salt-dried fishes (salmon, saury pike, and horse mackerel) are examined.
The antioxidative effect of Na-erythorbate on salt-dried fishes was evaluated both by organoleptic test and by measurement peroxide value. The available period was decided within 15 days, and better result was obtained at the concentration of 0.5% Na-erythorbate to dry salt than at 1%. But fishes are kept in better quality when they were treated with 0.5% Na-erythorbate solution before salting.
Antioxidative effect of BHA is larger when it was applied with Na-erythorbate than was applied it alone.
As Na-erythorbate is very soluble in water and easily penetrates into fishes, fish oil may be protected from oxidation by the antioxigenic ability of Na-erythorbate until BHA penetrates into fish oil to such quantity as it demonstrates its ability. Thus, the main cause of the synergistic ability of Na-erythorbate may be attributable to the water soluble property of this chemical.

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One of the present authors previously proposed the use of reflectance constant (K_R) as an indication of the rate of browning⁷⁾.
In the present work, the possibilities of the use of K_R was examined in detail. The results may be summerized as follows. Reflectance and K_R were obtained with flounder flesh to which various amounts of caramel were added (Table 1). K_R value linearly correlated with the concentration of caramel (Fig. 2), while reflectance at 500mμ correlated with logarithm of the concentration of caramel (Fig. 1). From these, it is considered that the use of K_R value is appropriate to express the rate of browning caused by amino-sugar reaction. Another advantage of the use of K_R was to eliminate the variation of reflectance due to species of fish (Fig. 3 and Table 2). Slight browning was observed on the flounder flesh with K_R of 2.5, and heavy with 3.0. Autoclaving of the flounder flesh below 115°C for 1 hour did not cause intense browning (Fig. 4).
The degree of browning varied among flesh from different parts of body or with different freshness (Table 3). At fresh stage, caudal muscles of most species tested showed a trend to be browned by autoclaving, while dorsal muscles of some species such as seabass browned strongly after storage. In the previous paper⁸⁾, it was shown that the caudal muscle of fresh seabasc contained greater amounts of hexose compounds than other parts, while the dorsal muscle contained greater amounts of pentose compounds. These facts suggest that hexose seems to be a limiting factor in the browning of fresh flesh, whereas pentose to be liberated from pentose compounds during storage plays an important role in the browning of stored or spoiled flesh, as postulated by JONES¹²⁾.

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Free amino acids, trimethylamine oxide, and betaine in the mantle muscle of six species of squids were determined, and interesting facts on the species-difference in the amount of components were observed, as shown in Table 2 and Fig. 1.
Squids having a better taste, such as Loligo chinensis GRAY, Loligo kensaki WAKIYA and M. ISHIKAWA, Sepioteuthis lessoniana FÉRUSSAC, and Sepia esculenta HOYLE, were rich in free amino acids, in which glycine, proline, and alanine were prominent.
In some squids inferior in taste, Ommastrephes sloani pacificus STEENSTRUP and Thysanoteuthis rhombus TROSCHEL, trimethylamine oxide was the dominent component with less amount of free amino adid, with single exception in arginine, than the other species of squids.
From these facts, such free amino acids, as glycine, proline and alanine are assumed to be responsible for the deliciousness of squids.

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The use of CTC makes the naturally occurring resistant bacteria predominant in the treated fish during storage³⁾. If CTC is to be used constantly it would be necessary to give sufficient consideration to antagonism between resistant and sensitive bacteria.
Experiments were made concerning the antagonism between CTC-sensitive and an invitro resistant strain of Pseudomonas fluorescens, a typical organism associated with putrefaction of marine fish, or a naturally occurring resistant strain of Pseudomonas, isolated from the CTC-treated fish.
Results may be summarized as follows:
1. In mixed cultures of sensitive and resistant cells, it was noted that without the presence of CTC the resistant bacteria were inhibited when the mixing ratio was 1:1. The larger was the ratio, the more conspicuous the antagonism was (Table 1 and 3).
2. In the presence of 1 ppm CTC, which was far less than the maximum tolerance level of the sensitive organisms tested, resistant organisms became predominant even in a 1:1 mixture (Table 2 and 4).
Even if a tetracycline is used repeatedly, putrefactive bacteria are expected to develop very low resistance^{1), 2)}. Nevertheless, sufficient attention should be paid to such possibility. It is not likely that naturally occurring resistant bacteria become predominant in nature, considering the growth antagonism between sensitive and resistant bacteria.

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