From the analysis of fish catch data and mark-recapture experiments the population density and movement of rose bitterling Rhodeus ocellatus ocellatus was determined. The mean of the catch per trap was considered as the index of the population density.
It was found that the population density was high in summer and very low in winter with a peak in late summer.
In the daily mark-recapture experiments using Neutral Red and Bismark Brown solution, about 90% of the recapture numbers in every month were found within 30-40m from the released points. A very few of the fish managed to cover a distance of 100m. In other mark-recapture experiments using fluorescent pigment, in a five month period more than 90% of the recaptures were made near their point of release, having covered only a distance of 200-700m. From these, it was concluded that only limited and localized fish movement occurred during the daily or the five month interval of the experimental period.
Fish abundance estimates based on the daily mark-recapture date of each month using the Petersen method were calculated as 13, 000-35, 300 fish for a 36m river shoreline for August and September when the fish catch was highest.

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To study the calcification of sea urchin, calcium level of each part (coelomic fluid, gut, gonad, lantern, tooth and test) was examined in Hemicentrotus pulcherrimus.
Calcium level of coelomic fluid (0.54mg/ml) was higher than sea water (0.41mg/ml) by about 30%. Test, lantern and tooth, which were calcified tissues, showed much higher level than gut and gonad. Relative content of calcium of calcified tissues was about 99.8% to the whole body. In the test, the highest level of calcium was observed in the area between the anus and the equator (339.8mg/g). Second highest areas were observed around the anus (298.0mg/g) and along teh equator (283.3mg/g), and the lowest area was found around the mouth (214.4mg/g), showing that calcium levels of the test varied with the different areas.

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The head kidneys of salmonid fishes, which had a unique dark brown color, were examined electron microscopically and were found to have a large number of cells with round to oval intracyto-plasmic electron-dense granules (EDG; 150-450nm in diameter) in hematopoietic tissue. Most of these cells were round-shaped with a peripherally located nucleus rich in chromatin. The EDG were surrounded by membrane structure. X-ray microanalysis showed that these granules contained a large amount of calcium when compared with other electron-lucent cytoplasm. By atomic absorption study, the calcium contents of kidneys in two salmonid fishes, rainbow trout Salmo gairdnerii and coho salmon Oncorhynchus kisutch, were significantly higher (150-190μg/g-tissue) than those of liver and spleen (56-108μg/g-tissue) in the same species and those of kidneys, liver, and spleen (59-114μg/g-tissue)in carp Cyprinus carpio.

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To obtain an index for the attractive effect of food, a logistic curve y_j=g/(1+e^-r(^j-a)), was applied to the time-courses, i.e. the observed y_j wiht the passing time from j=1 to 10min., for three behavior patterns (entered, left, and remained in the test compartment containing food) of oriental weatherfish Misgurnus anguillicaudatus. Of 28 (7 series×4 kinds of food) time-courses in each behavior pattern, and 27 (entered), 16 (left) and 27 (remained) time-courses fit the logistic curve with 0.10 level by chi-square test.
Among the nine coefficients (g, r and a for each behavior pattern), coefficient a of the logistic curve for the oriental weatherfish which remained in teh test compartment coincided with the general evaluation of the attractive effect. The following three reasons explain this coincidence: (1) this coeffcient reflects the average remaining time, (2) the evaluation by behavior was based on the average remaining time, the number of fish that remained, and their exploratory and feeding activity, and (3) the second and third criteria have a close relation to the first one.

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An investigation was made on infestation of the shells of 119 abalone Haliotis diversicolor aquatilis from southern Japan, with burrowing polychaetes Polychaetes Polydora by direct microscopic and soft X-ray radiographic means.
The total 698 specimens of Polydora were collected from the shells of abalone, and the relative number of these worms was 64.5% of P. armata, 25.6% of P. websteri, 9.0% of P. flava orientalis and 0.8% of P. ciliata. The frequency of occurrence of Polydora in the shells of abalone was 33.6% of P. websteri, 14.8% of P. flava orientalis, 5.9% of P. armata and 2.5% of P. ciliata.
Specimens of Polydora were obtained from the shells over 29mm in length, and the borers increased in number with the size of shells. The data indicated that the flesh weight of abalone decreased significantly by the infestation with more than ten individuals of Polydora per shell.

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The intracellular digestion of proteins by the rectal epithelium cells in larave and juveniles of five teleost species was investigated using horseradish peroxidase (HRP) as a marker substance. The HRP injected into the intestinal lumen was ingested from the apical surface of the cells, and was transported to the supranuclear area and then accumulated in several large granules. The supranuclear granules then changed to a number of small granules decreasing their HRP activity. The HRP activity finally disappeared from the small granules.
The time required for complete digestion of HRP by the cells differed with species, 7 to 15 days in Oncorhynchus masou and 10 hours to one day in Hypomesus olidus. In H. olidus, stomachless larvae showed a higher ability of intracellular digestion than juveniles in which the gastric glands have already been developed.

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It was demonstrated that males of rose bitterling Rhodeus ocellatus ocellatus were able to discriminate post-ovulatory females from pre-ovulatory ones on the basis of a chemical cue. And also males of slender biterling Acheilognathus lanceolatus were able to discriminate between post-ovulatory females and pre-ovulatory ones on the basis of a chemical cue. Some important aspects derived from the experiments are listed as follows;
1. Post-ovulatory females of each species released a female sex pheromone respectively, which males detect by olfaction.
2. The pheromone of each species was present in the genital cavity fluid and in the ovaries of post-ovulatory females.
3. Males of each species discriminated post-ovulatory females of their own kind from those of other species by olfaction. And difference of female sex pheromone was observed between the two bitterlings.

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It was demonstrated that males of Yamame Oncorhynchus masou were able to discriminate post-ovulatory females from pre-ovulatory ones on the basis of a chemical cue. And also males of Amago O. rhodurus were able to discriminate between post-ovulatory females and pre-ovulatory ones on the basis of a chemical cue. Some important aspects derived from the experiments are listed as follows;
1. Post-ovulatory females of each species released a female sex pheromone respectively, which males detect by olfaction.
2. Female sex pheromone of each sepcies played some essential roles in the courtship behaviour of each species, such as informing males of the occurrence of ovulation in females, at-tracting males and eliciting persistent courtship of males.
3. Courtship behaviour of males of each species was elicited only by post-ovulatory females of their own kind. And males of each species discriminated post-ovulatory females of their own kind from those of other species by olfaction. Therefore the species-sepcificity of the pheromones was observed in the two salmonids.

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The effects of heating in acidic media on the survival and deoxyribonucleic acid (DNA) lesion of spores were studied in comparison with those in neutral pH media. The repair of heat-injured DNA in germinating spores was also studied. By heating at 70°C for 60min in neutral pH medium, DNA in spores was scarcely injured, but at pH 5.0 much of the spore DNA was broken. It is thought that the acid-heating introduces alkali-labile lesions(apurinic sites) in DNA. There fore, the DNA breakage in this case probably took place through 2 steps, namely (1) the depurination by acid-heating and (2) the subsequent split of the depurinated sites by alkaline treatment.
When the spores of B. subtilis which were heated at 70°C for 20 min at pH 5.0, were incubated in germination medium at 37°C for 120 min, the alkaline labile sites in DNA were restored. Under this condition the number of survivals was not much reduced. The process of DNA repair corresponded to the DNA synthesis during germination.

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The Ca²⁺ -ATPase activity of fish myosin was activated by N-ethylmaleimide (NEM) treatment, while the EDTA-ATPase activity was inhibited. These changes indicate that fish myosin, like rabbit myosin, contains first reactive thiol groups (SH₁).
On the other hand, myosin SH₁ in myosin B system was completely unreactive with NEM under the conditions where the association of actin-myosin occurred, i.e., at physiological ionic strength and pH, and in the absence of ATP. These results suggest that myosin SH₁ in fish muscle may be masked with actin under the conditions of postmortem storage. The Mg²⁺ -ATPase activtity of myosin B, however, increased by NEM treatment under the conditions where SH₁ was unreactive.
It was also found that the thermal stability of the ATPase activity of fish myosin B. on storage at high ionic strength, was decreased remarkably by the NEM treatment. This thermal instability of the NEM treated myosin B may be due to the dissociation of myosin and actin.

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Two methods were examined. In one method, the anolyte was first adjusted to the pH value for maximum coagulation by mixing of a part of the catholyte. The resulting coagulum was recovered. Then the mixture without the coagulum was mixed with the remainder of the catholyte; the coagulum which was produced at that time was also recovered. The anolyte was finally mixed with the catholyte in 1:1 volume ratio. The final mixture was almost neutral. The over-all coagulation was 71-81%, regardless of the concentration of protein. In the other method, the anolyte and catholyte obtained were electrolyzed again after the inversion of electrodes until the electrolytes were almost neutral. The coagulation in the method was about 35%. This coagulation is less than the coagulation obtained in mixing the anolyte directly with the catholyte in 1:1 volume ratio. The recovery seems to be due to dissolution of the coagulum in the strong alkali layer produced near the cathode.

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Two diethyl ether soluble toxins (PL toxin-I, II) and one 1-butanol soluble toxin (PL toxin-III) were isolated from a benthic marine dinoflagellate Prorocentrum lima. The major toxic component, PL toxin-II, was purified by several steps of column chromatography to yield colorless crystals: mp. 156-158°C, [α]²⁰D+23° Physical and chemical data pointed to a molecular formula C₄₄H₆₈O₁₃ having four hydroxyls, one carboxyl, seven ether linkages, three olefins, and five methyls in the molecule. A further examination of its properties and a comparison with an authentic specimen established that PL toxin-II is identical with okadaic acid, recently isolated as a cytotoxic component of two sponges Halichondria okadai and H. melanodocia.

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The technique of comparisons of the thin layer isoelectric focusing patterns of sarcoplasmic protein was applied to identfication of fish species.
One gram of muscle tissue was blended with 2ml of 0.01M phosphate buffer, pH 7.0, and centrifuged at 12, 000rpm for 20min. The resulting supernatant was used for the sarcoplasmic protein pattern analysis. Isoelectric focusing was carried out on an LKB Multiphor apparatus using Ampholine PAG plate, pH 3.5-9.5 gradient.
Preliminary studies showed that the sarcoplasmic protein of a species of fish exhibits essentially the same pattern, irrespective of the body size, and any location of muscle which was taken from ordinary muscle. Frozen storage below -20°C for 42 months did not affect the pattern significantly.
Forty-one species of fish were analyzed for sarcoplasmic protein. The results obtained showed that the patterns are species-specific in many of the fishes tested, while the patterns are polymorphic in some fishes (such as black cow tongue Rhinoplagusia japonica, black sea bream Mylio macrocephalus, gizzard shad Konosirus punctatus, frigate mackerel Auxis tapeinosoma, carp Cyprinus capio and Tilapia nilotica). Even with those fishes, however, the identification of each species was possible, to some extent, by comparing some protein bands specific to each species. Rather exceptionally, the fishes belonging to the genus Thunnus or Tetrapturus showed patterns too similar to be distinguished from each other.

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Water-soluble fractions of the orange coloring substance of canned skipjack meat were investigated. The water-soluble pigment was separated into six fractions by Sephadex G-15 gel filtration. The first and major fraction, the one having high molecular weight, exhibited an intensive orange color, strong biuret reaction, and weak ninhydrin reaction. The fractions with lower molecular weights had a low biuret and high ninhydrin reactivity.
The first fraction was precipitated in the presence of 10% trichloroacetic acid. Non-heat-coagulable fractions prepared from water-soluble proteins of raw skipjack meat, when cooked with G6P, produced orange pigments having a similar gel filtration behavior to that of the first fraction. A gel filtration pattern of pigments prepared from His-G6P mixture resembled that of the fractions with lower molecular weights which were mentioned above.
These results emphasize the importance of the water-soluble non-heat-coagulable proteins in the orange coloration of canned skipjack meat.

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A six week feeding experiment was conducted to study effects of methionine coated with various materials added to soybean meal diet on growth and feed efficiency of fingerling carp and channel catfish. the coating materials used were aldehyde treated casein, acid treated casein, and hydrogenated tallow. Supplements of methionine, either coated or uncoated, significantly improved growth and feed efficiency of both species. In carp, addition of methionine coated with aldehyde treated casein significantly enhanced growth over that of uncoated methionine. But in channel catfish, coating methionine with any type of material did not significantly improve the utilization of supplemented methionine. Comparded to the group fed the diet with uncoated methionine, addition of methionine coated with acid treated casein to the diet significantly depressed the growth of channel catfish. These results indicate that both carp and channel carfish can utilize crystalline methionine supplmented to soybean meal and that utilization of crystalline methionine by carp can be improved further by coating it with aldehyde treated casein.

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The effects of carnosine, anserine, and balenine on the buffering capacities and the taste of meat extracts were studied. The titration curves indicated that these dipeptides possessed strong and almost identical buffering capacities above pH 6 and required about 0.6mol NaOH/1mol to raise the pH from 6.5 to 7.5. The buffering capacities were determined on the composite simulated estracts (CSE). These were prepared by mixing authentic reagents to reproduce the natural meat extracts (ME) from the shark Lamna cornubica and the sei whale Balaenoptera borealis, which contained a considerable amount of anserine and balenine, respectively. About 90% of the buffering capacities of ME were accounted for by the amino acids, organic bases, nucleotides, organic acids, sugars, sodium chloride, and the dipeptides; among these, the dipeptides made the important contribution in the physiological pH range. Carnosine and anserine show sweetness and a slight bitterness, whereas balenine shows bitterness and a slight sweetness. However, CSE containing anserine or balenine was more meaty than that without the dipeptides. The taste profiles of consommé with or without carnosine or balenine, at three different pH's, were compared by the triangle difference test. The dipeptides enhanced only sourness at pH 5.7, but enhanced sweetness, heaviness, and thickness at pH 6.8 and 7.6. These changes in the taste profiles seemed to be due not only to the dissociation of the imidazole residue but also to the buffering capacity of the dipeptides.

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The L-amino acid oxidase of the marine red alga Gymnogongrus flabelliformis was partially purified and studied.
The enzyme was purified about 45-fold in a yield of 13% by means of acetone precipitation, gel filtration, and DEAE-Sephadex column chromatography. This enzyme had very limited specificity, catalyzing the oxidative deamination of basic L-amino acids and methionine. The relative activeties for the amino acids at pH 8.0 were as follows: 100 for L-gigartinine, 84 for L-arginine, 83 for L-ornithine, 54 for L-lysine, 29 for L-citrulline, 23 for L-histidine and 20 for L-methionine. D-Amino acids were not oxidized. L-Arginine, which was used as the substrate of the enzyme reaction was oxidized to equimolar amounts of α-keto acid and ammonia with consumption of equimolar oxygen. Hydrogen peroxide formation was also detected. These results led the authors to postulate that the enzyme is a kind of L-amino acid oxidase. The pH-activity curve had a relative broad maximum between pH 8.0 and 9.0. The optimum temperature was about 30°C. The enzyme activity was inhibited by the treatment of EDTA, but it was reactivated by some metal ions. Ca²⁺ was the most preferable. The occurrence of L-amino acid oxidase in marine algae is demonstrated for the first time.

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Meat textured krill protein concentrate (MT-KPC) was manufactured from various types of materials made from Antarctic krill Euphausia superba, such as: A, raw peeled meat; B, peeled meat frozen and stored at -40°C; C, peeled meat frozen and stored at -20°C; D, frozen surimi made from peeled meat obtained by using a roller-type peeler; E, frozen surimi from peeled meat obtained by centrifugation; F, meat-homogenate from frozen krill.
Essentially the same method was applied as reported previously to make MT-FPC from Alaska pollack. The colour of the product was pale pink and the form was granules or chips; the product had a shrimp-like flavour and good rehydration capacity.
Products made from C and E were more fragile and powdery than those made from A, B, and D. An estimation of solubility and SDS-gel electrophoresis showed the denaturation of the proteins in C and E to have progressed more than that in A, B, and D. Production of MT-KPC from F was not possible because of the high degree of decomposition of the myofibrillar protein. The amino acid composition of MT-KPC was very similar to that of raw krill muscle.
Sensory evaluations showed that MT-KPC made from the above-mentioned materials could all be used as the main material or as a partial substitute for shrimp meat in a variety of styles.

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The swelling of spores of Bacillus subtilis during germination was followed by measuring changes in the cell volume by means of the Coulter Counter method. It is generally recognized that there are three stages of swelling: (1) germination swelling involving a rapid increase of cell volume as the spore germinated, (2) pre-emergence swelling of cell volume before emergence from the spore coat, and (3) elogation. The spore volume increased about 30% after 40 min of germination in the Demain's germination medium. to confirm the accuracy in sizing by the Coulter Counter method, electron microscopic observation was done. The two results coincided.

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