Cs/K atom ratios were examined in Japanese coastal waters and biota. The Cs/K atom ratios in
coastal waters, chlorophyta (3 species), rhodophyta (10 species), phaeophyta (4 species), invertebrates
(7 species), teleosts (15 species) were 2.1, 2.1, 1.9, 4.6, 3.5, 12 (×10^-7), respectively. The Cs/K atom ratios were especially large in teleosts examined.
Cs/K atom ratios in organisms increased with the elevation of the trophic levelsof the organisms. An “increase ratio” of Cs/K ratio was approximately 1.62 per one step elevation of trophic level.
The highest Cs/K atom ratios observed in teleosts suggested both the discrimination of Cs from K in teleosts and the discrimination of Cs from K in transferring these elements along food chains.

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A multivariate autoregressive model is adapted to analyse and to forecast fishing and oceanographic conditions. Generally the optimal model is determined by minimizing the AIC within the Gaussian model. Whereas in the case an error term cannot be assumed to be Gaussian, the modification of this is expected to lead to abetter model. In this study we proposed a method to partly modify error terms which are assumed to be Gaussian distribution by Cauchy distribution. As for theexample, the variation of the distance of the appearance of the Kuroshio axis from the coast was analysed. Replacing the error term in the model by Cauchy distribution, AIC was diminished in comparisonto that of the Gaussian model and consequently the model was improved. After defining the optimal model, we made trials of checking the performance of the model that adapted the Cauchy distribution bysimulating the variation of the Kuroshio. The result of the 100 trials showed that the introduction of non-Gaussian model made the simulated fluctuations closerto the real data.

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Geographic variation in the skull morphology of the finless porpoise was studiedwith special reference to identifying local populations in Japanese waters. Twenty-five skull characters were measured for 146 specimens. These specimens were divided into five samples on the basis of available distributional information: 1) from Sendai Bay to Tokyo Bay, 2) Ise Bay and Mikawa Bay. 3) Inland Sea and theadjacent waters, 4) Omura Bay, 5) Ariake Sound and Tachibana Bay. Morphological differences were examined by the analysis of covariance and canonical discriminant analysis. The skull morphology varied among the samples. The porpoises in IseBay and Mikawa Bay possessed rather narrow skulls. There was no evidence that skull morphology was more similar between geographically close areas. Such geographic variation suggests that porpoises in each area rarely intermingle. We considered that there are at least five local populations in Japanese waters.

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Sexual maturation with age was analyzed for arrow squids Nototodarus gouldi and N. sloanii in New Zealand waters. A total of 654 specimens of N. gouldi and 771 specimens of N. sloanii were aged successfully using the statolith micro-structure. Based on the results of ageing, the relationships between age and some gonadsomatic indices were analyzed. The maturation patterns of both species are similar to each other, though the sample number of mature N. sloanii is not sufficient. The change of gonad somatic indices suggests that males start to mature from around 200 days old. Testis somatic index (TSI) reaches a maximum at about 270 days. Females start to mature at the time when TSI reaches the maximum in males. The development of ovary, oviduct, and Nidamental gland occurs simultaneously, and copulation also occurs at the same period. It is suggested that spawning may occur within two months after copulation, considering the period of copulation and a single year life span of arrow squids.

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Based on the results of the two Japan/New Zealand joint surveys, the distributions of the arrow squids Nototodarus gouldi and N. sloanii at paralarval and juvenile stages are described. The paralarvae of N. sloanii were distributed on the shelf and banks shallower than about 150m depth. The juveniles of N. gouldi ranged from 20-40mm DML and were distributed mainly on the continental shelf off the east and west coasts of the North Island and north-west of the South Island. On the other hand, the juveniles of N. sloanii were distributed on the continental shelf along the east and south coasts of the South Island, on the Auckland Islands shelf, and around the Chatham Islands. These distribution patterns at paralarval and juvenile stages are very similar to the distributions of adult squids. It is concluded that the two Nototodarus species are distributed in shallow water, mainly on the continental shelf throughout their life histories. It was estimated that the paralarvae and juveniles observed in the surveys were hatched mainly in April/June (austral autumn).

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The visual contrast threshold of Japanese common squid Todarodes pacificus Steenstrup was sought through a series of experiments by observing their responses to contrast test boards. The contrast test boards consisted of three vertical stripes of which the outer two were painted in black and the middle band was in 11 different hues from white to black, exhibiting the apparent contrast values of 31.3 to zero (O). The experiments were carried on under the light intensity of 1.01x at the water surface, and the total number of squid used was 68.
When an experimental squid was confronted with the test board of which apparent contrast was less than 0.63, he made a jet-hit response to it. This jet-hit response was particularly prominent when the apparent contrast was less than 0.008 and decreased in frequency with the increase of contrast value. At contrast values above 1.45, he avoided the middle band. By means of the 50-percent point of jet-hit response probability, the visual contrast threshold of the squid was estimated to be 0.006.

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A new test for antifouling substances against the young blue mussels, Mytilus edulis galloprovincialis was developed. Mussels crawl around and search, using their foot, for a suitablesubstratum to attach themselves to by byssus threads. Repellent substances applied to the substratum inhibit this behavior, leading to the present assay method which is simple and fast, and allows an evaluation of, not only repellent activity, but also toxicity of samples. This assay method can also be carried out under the con-ditions closer to natural than those of previous methods, causing less stress to test organisms. The minimum repellent concentration of p-nonylphenol, which is a known repellent, was one order of magnitude lower when evaluated by the present method than that by the “byssus-thread method”, while cupric sulfate was evaluated similarly by both methods. This method is, therefore, useful for the discovery of nontoxic, antifouling substances from natural sources, including marine organisms.

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The behavior of killer whales Orcinus orca during bottom longline fishing operations has been investigated in the Bering Sea and adjacent waters. Observations of fishery interactions with killer whales depredating longline caught bottom fish were noted during the Japan-U. S. cooperative longline research survey in 1988. During the survey, 15 of 108 stations encountered killer whales. Based on field observations and photographs of killer whales, we have identified three killer whale groups (BS1, BS2, and BS3) in the Bering Sea fishery interactions. Group size ranged between 4 and 50 whales. The time between the initiation of fishing and the first sighting of killer whales near thevessel varied considerably. With the start of hauling operations, the average time that elapsed before killer whales first arrived was 106 minutes with a range of-10 (killer whales observed 10 minutes prior to hauling operations) to 294 minutes. During depredation, killer whales stayed near the vessel from 62 to 331minutes. During most interactions, whales approached within 10 to 500m. At the start of the operations, whales were seen father away from the vessel (100-150m) but would swim closer as fishing continued (10-100m). There is some suggestion that killer whales depredate on fish at water depths of 200-300m or more.

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Feeding ecology of juvenile masu salmon, Oncorhynchus masou, collected by commercial set nets, was studied in the coastal waters of Hokkaido between 1991 and 1993. Stomach fullness indices varied among sampling dates and two areas sampled (Japan Sea and Pacific Ocean). The stomach contents of juveniles collected along the coasts of the northern Japan Sea were composed entirely of sand lances (Ammodytes personatus), which were 1/4-1/2 of the body lengths of the juvenile salmon. In contrast, stomach contents of the juveniles collected along the coast of the Pacific Oceanincluded a variety of organisms, and size ratios of prey to juveniles were lower than those in the northern Japan Sea. The results of comparisons of juvenile stomach contents between the Japan Sea and Pacific Ocean indicate that juvenile masu salmon occupy different ecological niches in the two areas. Production of juveniles in the northern Japan Sea may depend on the abundance of sand lance.

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Chromosome studies were carried out on six species of genus Takifugu: T. niphobles, T. pardalis, T. poecilonotus, T. radiatus, T. rubripes, and T. xanthopterus, which are found commonly in coastal waters of northern Kyushu, Japan. Chromosome preparations were made from kidney tissues with conventional airdry method. Chromosome numbers were determined as 2 n=44 and new arm numbers were determined as 46 in all the species. Karyotype analyses indicated to have 4m + 16 sm + 24 st or ac in T. niphobles, 6m + 16 sm + 22 st or ac in T. pardalis, 12 m + 10 sm + 22 st or ac in T. poecilonotus, 8m+ 14 sm + 22 st or ac in T. radiatus and T. xanthopterus, and 10m + 12 sm + 22st or ac in T. rubripes. Fundamental number (FN) of five species were determined as 66 except T. niphobles which had 64 in FN. Therefore, it was estimated that the chromosome complements of these fishes were remarkably similar. So, the occurrence of the natural hybrids of this genus Takifugu might be related with similarity of their karyotypes.

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The induction of cytochrome P4501A (CYP1A) mRNA in red sea bream Pagrus major was investigated using CYP1A cDNA. The CYP1A cDNA was derived from a 3-methylcholanthrene (MC)-inducible mRNA of P. major. CYP1A mRNA was induced in the liver, gill, gut and kidney after an intraperitoneal injection of 3-MC, although the induction levels of mRNA were different among these organs. Results of the time course experiment showed that the CYP1A mRNA content rapidly increased immediately after the 3-MC injection, then showed a slight decrease prior to a further increase until at least 70h after the injection. The CYP1A mRNA content increased in a concentration-dependent manner when fish were treated with various concentrations of 3-MC. The effect of water temperature on the induction of CYP1A mRNA was examined. The level of mRNA content was approximately double in fish maintained at 15°C of sea water than those at 11°C and 19°C. However, the induction levels of CYP1A mRNA were still higher in fish at 11 and 19°C than in the control fish.
These results suggested that the CYP1A mRNA may be useful as a biological indicator of the presence and concentration of chemical pollutants.

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Effects of temperature on nitrogenous excretion of Japanese flounder were examined at 16, 20, and 25°C with fish of 1.3 to 9.7g (juvenile), 57.2 to 100.6g (young), and 265.9 to 535.0g (immature) in body weight. The ammonia excretion rate of the starved flounder increased with an increase of temperature at all developmental stages. Temperature did not affect the urea excretion rate of juvenile and young fish, however, the rate of immature fish showed a similar trend to the ammonia excretion. Diurnal patterns of ammonia and urea excretion of juvenile fish after feeding were similar to each other among temperatures tested. Daily rates of ammonia, urea, and feces nitrogen excretion of the fed fish tended to increase with an increase of temperature, as well as the proportions of these substances to the consumed nitrogen.

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Histopathological and scanning electron microscopic observations were performed in the lesional tissues of the test and appendages of the sea urchin Strongylocentrotus intermedius affected by “spotting disease.” Spotting lesions with blackish red color on the test surface, separation of spines and attachment failure of tube feet are typical external signs. The epidermal lesions of the test and appendages is disorganized and infiltrated by migrating coelomic red spherule cells (eleocytes) and brown granules. Muscle fibers in the spine base, tube feet and ampullae are fragmented. These pathological signs are very similar to those of the bald-sea-urchin disease in S. purpuratus and S. droebachiensis. Invasions of the ameba Paramoeba invadens that was identified as a pathogen of thebald-sea-urchin disease, were not found in the diseased S. intermedius. However, seriously damaged epidermis, dermis and connective tissue were invaded by bacteria, one of which was a filiform bacillus. The results suggest that the spotting disease of S. intermedius would associate with a bacterial infection.

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Two types of GnRH contents, salmon type (sGnRH) and chicken-II type (cGnRH-II) were measured in the brain of goldfish after olfactory tract section in order to characterize the effects of the olfactory tract section on brain GnRH content and to determine an appropriate time for use of the olfactory tract-sectioned fish after the operation. Brain sGnRH contents started to decrease at 7 days after the operation, reached low levels by 14 days, and were decreased up to 56 days afterthe operation. Brain cGnRH-II contents showed no clear changes up to 56 days after the operation. Theresults indicate that it is appropriate to use olfactory tract-sectioned fish 14 days or later after the operation when the influence of GnRH of terminal nerve origin has been removed.

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After the harpacticoid copepod Tigriopus japonicus was cultured at 25°C on Tetraselmis tetrathele for several generations at 4, 8, 16 and 32 ppt, reproductive characteristics such as brood size, sex ratio, survival and mature age were studied. Results showed that 32 ppt was the best salinity for the population growth since significantly more nauplii were produced, reached the mature stage earlier, and had higher survival rates and longer lifesan. Sex ratio of a brood was not affected by different salinities. Sexual maturation occurs at younger stage with higher survival in offspring from broods produced by younger mothers. The male is dominant in the population. Instrinsic rate of increase (γ) was 0.150, 0.218, 0.273 and 0.276 at 4, 8, 16 and 32 ppt, respectively.

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We investigated the interaction between marine rotifer Brachionus rotundiformis (formerly called S-type B. plicatilis) and zooplankton species which contaminate in the rotifer mass culture tanks. These species include Brachionus plicatilis (formerly called L-type B. plicatilis), Diaphanosoma celebensis (cladoceran), Tigriopus japonicus (copepod) and Euplotes sp. (protozoan). We compared the population growth of 40ml single-species and two-species of mixed cultures fed on phytoplankton Nannochloropsis oculata at 8×105 cells/ml (food limitation level).
We observed three manners of interspecific relations that include competition, commensalism and amensalism. Predations or mechanical damages were not observed between tested species. The population growth of B. rotundiformis, B. plicatilis, and D. celebensis in mixed-species cultures were significantly suppressed when compared with those in single-species cultures. This indicates that the competition for the limited amount of food suppressed mutual population growth. Thepopulation growth of B. rotundiformis was not affected by the co-existence of T. japonicus, however. T. japonicus grew better when cultured with B. rotundiformis. Contrary, the existence of B. rotundiformis did not affect the growth of Euplotes sp, but Euplotes sp. population interferes the growth of B. rotundiformis. These suggest the possibility of bacterial intervention in the interspecific relation of T. japonicus and Euplotes sp. with B. rotundiformis.

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Marine bacteria that kill the noxious red tide flagellate Chattonella antiqua (Raphidophyceae) were screened and isolated from northern Hiroshima Bay, the Seto Inland Sea, Japan in 1991. Four strains (S, K, D, R) of Alteromonas spp. were selected and examined on characteristics of algicidal activities. Strains S and R showed wide algicidal range killing all cells of the 3 raphidophycean flagellates, 2 diatoms, and one dinoflagellate examined, in co-culture. Algicidal activities of the strains K and D depend on prey phytoplahkton species. Bacterial culture filtrate experiment shows that the bacterial strains K and D give lethal effects on C. antiqua by means of extracellular products, and the strains S and R not by such substances but by predation. If one or two bacterial cells were inoculated into C. antiqua culture, all of the host cells were killed by the 4 strains of algicidal bacteria within 7 days. All of the 4 bacterial strains could proliferate in filter-sterilized seawater, indicating theirubiquitous existence in the coastal sea. We suggest that the algicidal activity by bacteria may be a significant factor influencing the population dynamics of phytoplankton, and potentially might account for rapid termination of red tides in the coastal sea.

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A method to measure noise at the output of echo integrators has been developed for precise estimation of fisheries resources by acoustic means. This method is more practical than the method to measure noise at receiver output, because noise contribution can be easily compared withthe volume backscat-tering strength (SV) of fish and because there is less ambiguity in noise measurement. Also a conversion equation of the echo integrator output to the equivalent noise spectrum level isderived. This facilitates the comparison, for example, between different echo sounding system.We applied this method to a dual beam echo sounding system on board research vessel Kaiyo-maru, and confirmed that the difference in noise SV of 5 dB agreed with the theoretical prediction.

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Acoustic surveys for studying the behavior of kokanee Oncorhynchus nerka in LakeKuttara, Hokkaido, have been conducted over the past ten years and several interesting results have been obtained. Kokanee were recorded on echograms as school echoes in the daytime and as numerous individual echoes in the nighttime. Their swimming layer changes seasonally in accordance with the depth change of thermocline in the lake. Kokanee also have a diurnal behavioral pattern. Namely, they form schools after sunrise and they disperse after sunset. The shifting process from individuals to schools or from schools to individuals is strongly related to illuminance, and it takes 50 minutes at sunrise and sunset for the change to occur. The swimming speed of kokanee in the daytime is faster than that in the nighttime, and the fastest speed of the day occurs at twilight. Average swimmingspeeds were estimated to be 57cm/s in the twilight, 48cm/s in the daytime and 20cm/sin the nighttime periods, respectively.

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The diurnal variation of the dorsal aspect target strength of encaged fish was investigated, and an attempt was made to estimate the fish tilt angle distributions. The experiment was conducted at Lake Kuttara in Hokkaido. In this lake, kokanee Oncorhynchus nerka are the dominant species. The net cage was made of nylon monofilament, had a volume of approximately one cubic meter, and was nearly acoustically transparent. Five kokanees, caught by gill net, were released into the net cage. During the experiment periods, the net cage was kept at a depth of 10m under the transducer which was driven by a 50 kHz transmitter. About 600 echoes from encaged fish occurring over a 24 hour period were measured and analyzed. The results obtained were as follows:
1) The shape of the dorsal aspect target strength probability density functions (PDFs) of encaged fish showed a large variation before and after sunrise and sunset.
2) Diurnal variation of the averaged dorsal aspect target strength of encaged fish was about 18 dB.
3) Some of the observed target strength PDFs agree approximately with estimated target strength PDFs based on fish tilt angle distribution which was assumed to truncated normaldistribution.

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The anticoagulant effects of potassium warfarin and the antagonistic effects of vitamin K₃ against warfarin were examined in the common carp. Warfarin (1.0mg/kg/day) with and without vitamin K₃ was orally administered to the common carp for 35 days, and prothrombin time (PT), Russell's viper venom time (RVVT) and the absorbance of the chromogenic substrate assay (CSA) using S-2337 were measured at intervals of 7 days. Prolongation of PT and RVVT, and a decrease in the absorbance in the CSA were observed after the oral administration of warfarin, indicating that both activities of the extrinsic and common pathways were affected. Supplementation with vitamin K₃ (0.1mg/kg/day) was effective in preventing the prolongation of PT and RVVT, but the decrease in theabsorbance in the CSA was not prevented. These findings suggest the existence of vitamin K-dependent factors involved in both the extrinsic and common pathways.

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The variations of the tensile strength of myosin gel during heating were measured based on an equation, which was derived from the thermodynamics of elastic deformation, in orderto clarify the mechanism of the elasticity of kamaboko. Myosin was extracted from the croaker Nibea mitsukurii, and 85mg protein/g gel/0.6M KCl was prepared by heating at 80°C for 20min. The myosin gel was extended to twice its original length, and successively heated by an electric heater alone or in combination with an infrared ray. A commercially available kamaboko and a rubber band were also submitted to the experiments to compare with the myosin gel. The tensile strength of both myosin gel and kamaboko increased and immediately decreased when these gels were heated by the electric heater and it continuously decreased with heating by an infrared bulb. In the case of rubber, on the other hand, the tensile strength increased continuously. From the results of myosin gel and kamaboko, the entropy of these gels was found to increase with elongation under a constant temperature. Hence, both myosin gel and kamaboko were found to have another mechanism for elasticity, different from that of rubber, or entropy elasticity. As a result, myosin gel was concluded to be an energy elastic body, not an entropy one.

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Toxin compositions in xanthid crabs Zosimus aeneus and Atergatis floridus were examined. Three specimens of each were collected on reefs of Ishigaki Island, Okinawa Prefecture, and were dissected into 6 parts; muscle of appendages, muscle of cephalothorax, skeleton of appendages, skeleton of cephalothorax, viscera, and gills. Toxicity of each tissue was determined by mouse bioassay and toxin compositions by high performance liquid chromatography (HPLC) with fluorometric detection. In both crabs, muscle of appendages gave the highest toxicities (1, 100 5, 900 MU/g)among the 6 tissues, and those of muscle of cephalothorax and gills were less than one tenth of it. In Z. aeneus, relative abun-dances (mole%) of carbamoyl-N-hydroxyneosaxitoxin (hyneoSTX) and neosaxitoxin (neoSTX) were rather high, and 10_??_15% of gonyautoxins (GTXs) were contained in addition to similar amounts of carbamoyl-N-hydroxysaxitoxin (hySTX), decarbamoylsaxitoxin (dcSTX), and saxitoxin (STX) irrespective of tissues except for gills. A. floridus possessed STX predominantly over the other STXs with no detectable amount of GTXs. In both crabs, gills had a somewhat different toxin profile from the other tissues with higher neoSTX and STX but lower hyneoSTX and hySTX. A good correlation was observed between the toxicities calculated from the results of HPLC analyses andthose from mouse bioassay.

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An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibody in serum of Japanese flounder, Paralichthys olivaceus against Edwardsiella tarda. Sera were collected from the flounder which had been injected with formalin-killed E. tarda cells (FKC). The sera were precipitated with a 40% saturated ammonium sulfate solution, and immunoglobulin (Ig) was purified from the precipitates by gel-filtration and ion-exchange chromatography. The purified Ig was administered to a rabbit to prepare anti-flounder Ig serum. Sensitivity of the ELISA was more than 6 times higher than that of formerly used agglutination methods.
The flounder were vaccinated by three different methods; intraperitoneal injection of lipopolysaccharide of E. tarda (LPS), immersion in LPS, and immersion in FKC solution. The titers of vaccinated groups except for immersion in LPS were significantly higher than that of a control group (p<0.05). However, in the challenge test, there were no significant differences in the survival rates between vaccinated and control groups.

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Rats were fed a fat-free diet with or without soluble dietary fiber in seaweeds, sodium alginate, to investigate the effect of fiber on digestive organs and fatcontents of liver and serum under the conditionof no fat. Food intake of rats fedon diets with alginate was smaller than that without alginate during the early feeding period, but there was no difference between the rats fed with basal and alginate dietson the final day. Body weight and body weight gain of rats fed withalginate were less than those fed without alginate. Fecal weight of the alginatediet group was the largest. Wet weights of digestive or-gans such as liver, spleen, pancreas, kidney, cecum, small intestine, and large intestine were not significantly different among each diet group. In the liver, fat concentrations were significantly higher inrats fed without fat than in those fed with fat. The fat content in serum of fat-free diet rats was the highest, whereas that of the alginate diet rats was the lowest.

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The suppressing effect of garland chrysanthemum Chrysanthemum coronarium L., on niboshi odor was studied by a combination of sensory testing, gas chromatography, and gas chromatographymass spectrometry.
In a sensory test, it was found that the niboshi odor was distinctly suppressed by the addition of garland chrysanthemum. Eight carbonyls and one alcohol identified in niboshi soup stock were also detected in the niboshi soup stock to which garland chrysanthemum was added, and two gas chromatographic patterns of these fishy volatiles were essentially the ame. On the other hand, eight compounds identified in garland chrysanthemum, whose main components were myrcene, β-ocimene, and trans-2-hexenal, were also detected in niboshi soup stock to which garland chrysanthemum was added. The effect of the addition of the above three authentic compounds (myrcene, β-ocimene, trans-2-hexenal) on niboshi odor was then examined using sensory tests.
It was concluded that myrcene, β-ocimene, and trans-2-hexenal greatly contributed to masking the odor of niboshi in cases where the garland chrysanthemum was added.

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Attempts were made to elucidate the responsible toxins in the gastropod Niotha clathrata and Zeuxis scalaris which recently caused food poisoning incidents inSouth Taiwan. The remained (cooked) and captured (live) specimens of both gastropods were assayed for toxicity (as tetrodotoxin=TTX). The average toxicity of cooked and live specimens was 150±126 (mean±S. D.) and 345±192 mouse unit (MU) in N. clathrata, and 13±9 and 98±46 MU in Z. scalaris, respectively. The toxin was partially purified from the methanolic extract of the gastropod by ultrafiltration and Bio-Gel P-2 column chromatography. Cellulose acetate membrane electrophoresis, TLC, and HPLC analyses demonstrated that the toxin consisted mainlyof TTX (about 80%), along with minor paralytic shellfish poison (PSP, about 20%). The PSP components were identified as gonyautoxin 1-4 and neosaxitoxin in bothgastr-opods. It was concluded from these results that the causative agents of theabove food poisoning were TTX and PSP.

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The changes of rheological properties of a cuttlefish and four squids by heat treatment were studied by the differential scanning calorimetry (DSC), the rupture test, and the stress relaxation test. Thethermograms of raw “ika” mantle meat showed three major endothermic peaks at 50°C, 57°C, and 74°C. The first andsecondpeaks mainly corresponded with the denaturation of myosin and collagen.The thirdpeak was that of actin which was almost native up to 63°, while the other proteins had been completely denatured below 63°. The thermograms for all samples indicated that the denaturation ofmantle meat had been completed up to 80°C. Then, the rheological properties were measured for rawmeat and heated meat at 63°C or 80°C. A positive correlation between the content of crude protein andthe instantaneous elastic modulus was only found in heated meat at 63°C. It is considered that thisrelationship was associated with the amount of remaining native actin.

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An orange pigment-producing bacterium, which was identified as Flavobacterium sp., was isolatedfrom a Palauan marine sponge Homaxinella sp. The main orange pigment was extracted from the cultured mycelium and purified by chromatographic method. It was identified as myxol by means of a spectral data. This is the first isolation of myxol, which is known as the aglycone of myxoxanthophyll widely distributed in cyanobacteria.

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Biochemical natures of calcitonin (CT)-like substance obtained from Brockmann bodies (BB) ofthe medaka Oryzias latipes (Teleostei) were examined. A crude extract of BB was fractionated byreversed-phase HPLC and screened with anti-salmon CT antisetum by Western blotting. Although 4 fractions showed positive immunoreactivity, CT-like biological activity was detected only in one ofthese fractions. The molecular weight of the identified CT-like substance was calculated as 20 kDa, which is considerably higher than that (3.5 kDa) of authentic CTs of other vertebrates.

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Effects of freezing, frozen storage, thawing, and cold storage after thawing onpost-mortembiochemical changes in scallop adductor muscle were studied. Freezing and frozen storage at -70°C did not affect the post-mortem biochemical changes in scallop adductor muscle.
The profile of ATP and its related compounds drastically changed by the thawing procedure: ATP entirely decomposed and AMP accumulated. These changes in the scallop adductor muscle by rapid thawing were smaller than those by slow thawing. The content of octopine increased during thawing, but that of D-lactic acid was unchanged.
During cold storage, the changes in the content ofATP and its related compounds, arginine, octo-pine, and D-lactic acid in thawed muscle were more remarkable than those in unfrozen muscle. AMP was rapidly converted into inosine (HxR) and hypoxhantine (Hx), and the amounts of HxR and Hx exceeded 65% of the total amount of ATP and its related compounds during cold storage after thawing. The degree of accumulation of octopine and D-lactic acid in thawed muscle during cold storage wasmuch larger than in unfrozen muscle. This suggested that activation of glycolysis was induced by the thawing procedure.

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A 2×3 factorial experiment was conducted using two degrees of oxidation of the 10% supplemental fish oils in the diet [fresh oil, peroxide value 17 meq/kg (FO)and oxidized oil, peroxide value 256meq/kg (XO)], three levels of supplementalL-ascorbyl-2-phosphate-Mg (APM) 0, 50 and 500mg/100g diet on red sea bream Pagrus major juveniles (initial body weight_??_3.36g). The fish grew 9-10 fold over a 60 days period of feeding in the groups of APM-supplemented with fresh or oxidized oil (50-FO, 50-XO, 500-FO and 500-XO) and showed better performance (weight gain, feed conversionefficiency, specific growth rate, survival), body condition (condition factor, hepatosomatic index, collagen content of bone), and biochemical parameters (tissue ascorbic acid and thiobarbituric acid value(TBA value) thanthe groups of APM-unsupplemented (0-FO and 0-X0). However, the analysis of variancerevealed that there was significant (p<0.05) interaction of APM-level andoil-type in the tissues ascorbic acid level and condition factor. APM had strong main effect on all variables whereas oil type hadnot. A depletion of APM from the diets (0-FO and 0-XO) resulted in accelerating lipid peroxidation ofmuscle measured as TBA value and low lipid accumulation as triglyceride in muscle and liver.

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High-pressure effects (50_??_300MPa) on lecithin-added yellowfin tuna actomyosin ATPase activities were investigated. A marked activation of lecithin-added actomyosin Mg-ATPase was manifestedby pressurizing up to 100 MPa for 10min, indicating a maximum value of 0.6_??_0.8mg lecithin/mg protein. There was no appreciabledifference in volume change obtained from Ca-ATPase activity betweenactomyosin with added lecithin and that without added lecithin. Upon application of high pressure at 150, 170 and 200 MPa the EDTA-ATPase activity of lecithin-added actomyosin (0.4, 0.6, and 0.8 mg lecithin/mg protein) markedly increased. It was assumedthat by pressurization lecithin played a significant role in the activation of actomyosin Mg-ATPase up to 100 MPa and in the dissociation into myosin and F-actin between 100 and 200 MPa.

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Free L-cysteine was detected in the cell sap of the green alga Valonia macrophysa using high perfor-mance gel filtration chromatography and fluorometric detection after pre-column derivatization with the thiol-specific reagent N-(7-dimethylamino-4-methylcoumarinyl) maleimide. Large quantities of cysteine (up to 39.3μg/ml) were detected together with small amounts of glutathione when cell sap was prepared without exposure to air at pH 2.0. On the other hand, when sap was exposed to air at pH 7.0 for 2h, cystine rather than cysteine was detected at levelsof 41.7μg/ml using post-column derivatization with ninhydrin reagent. Since the molar ratio of cysteine to cystine was 1.8:1.0, it is probable thatcystine was derived by oxidation of cysteine that must accumulate in cell sap in situ. When the levels of half-cystine were measured for other cell compartments it was found that high molecular weight compounds in cell sap contained high amounts of half-cystine (18.0% of total amino acid pool) compared to the water insoluble fraction of protoplasm-layer and cell wall fractions which contained 8.9% and 7.6% half-cystine, respectively.

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Salmon surimi has not been preferred commercially due to its poor gel formability resulting from the absence of setting response. The causes were investigated. It was found thatthe activity of transglutaminase extracted from the salmon surimi was too low to produce cross-linkedmyosin polymers and to set gels. In addition, the contents of myosin and Ca²⁺ were also lower than those in walleye pollack surimi. The inhibition of protease activity did not enhance the polymerization of myosin at all. Salmon actomyosin could be cross-linked in great extent by carp transglutaminaseand resulted in the gelation. Although the enzyme-inducedset gel was formed from salmon actomyosin paste, carp transglutaminase supplied to salmon surimi paste did not induce the myosin cross-linking nor did the gelation. This result suggests the presence of factors inhibiting the enzyme activityin the salmon surimi paste.

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