Trachurus Japonicus Research Articles

Color and Gel‐forming Properties of Horse Mackerel (Trachurus japonicus) as Related to Washing Conditions

ABSTRACTA beneficial decoloration effect resulted for horse mackerel mince washed with ozonized water within 10–20 min, but a longer washing time was required to improve the color properties when cold water or alkaline solution was used. Increase in pH as well as improvements in gel‐forming ability occurred for mince washed with alkaline solution. The maximal gel strength of surimi was found when washed for 90 min. A marked decrease in pH and an undesirable gel strength of mince, as well as oxidation of the fish oil occurred during ozone treatment. Since the salt‐soluble protein concentration increased for all minces washed with the three methods, improvement in gel‐forming ability of washed mince was attributed to the increase in pH rather than to oil removal.

ストロボ光の威嚇効果に関する行動生理学的研究‐ＩＩ ストロボ光頻度によるマアジの心拍数変化

The stimulating effect of strobe light on jack mackerel Trachurus japonicus was examined for the heart rate change under different flash frequencies. Heart rate change was clearly observed to increase during strobe flashing, with a tendency of sudden decrease immediately after ending of the stimulus. The observation was repeated three times for each individual with an interval of two hours. The data analysis focused on the stimulating effect of the strobe light with flash frequencies ranging from 1.7 ?? 430Hz, as well as habituation by repeated trials. Under these test conditions, the flash frequencies of 5 and 10Hz produced the strongest effect of strobe stimulus. There was no significant decrease of the stimulating effect by the repeated trials, suggesting that of habituation does not occur.

Effect of Measuring Temperature on the Physical Properties of Horse Mackerel Gels.

In order to investigate the difference in the protein network structure among suwari gel, kamaboko gel, and suwari-kamaboko gel, the effect of measuring temperature on their visco-elasticity was examined. These gels were prepared from the same surimi paste of horse mackerel Trachurus japonicus, by setting at 40°C for 1h, by heating at 80°C for 30min, and by heating at 80°C for 30min after setting at 40°C for 1h, respectively. With rising the measuring temperature from 5°C to 40°C, storage modulus and loss modulus obtained by dynamic test, elasticity modulus and viscosity obtained by stress-relaxation test, and compression stress before breakage in a puncture test decreased for all the gels but the breaking force and breaking deformation increased. Furthermore, master curves could be drawn from the time-stress curves recorded by the puncture test for these gels. Based on the above results, the network structure in these gels and its dispersion in them were discussed.

相模湾西湘地域の定置網における複数魚種の漁獲量予測

In this paper the supervised learning paradigm with three layered networks and backpropagation algorithm of artificial neural networks were used for forecasting catches of multiple species in set nets. Three-month means of CPUE of jack mackerel Trachurus japonicus, Japanese sardine Sardinops melanostictus, chub mackerel Scomberjaponicus and total catch for all species in set nets of the Seishyo region in Sagami Bay were collected as output vectors. The input vectors of oceanic conditions were the average temperature anomalies around the set nets and at the surface and 50m depth in Sagami Bay, the Kuroshio path type, and the distances of the Kuroshio current from Cape Irou-zaki and Cape Nojima-zaki. We examined four cases of networks considering fish species and fishing seasons. The CPUE of jack mackerel and total catch in the set nets can be predicted from those of the preceding period and oceanic conditions. Predictions using the same season data were more successful than those using the preceding seasons.

Glutathione Peroxidase Activity During Storage of Fish Muscle

ABSTRACTActivity of fish muscle glutathione peroxidase, which presumably protects muscle from oxidative deterioration during storage and processing, was found in both Japanese jack mackerel and skipjack tuna. Activity of the peroxidase and level of reduced glutathione (enzyme substrate) decreased during 5 days storage at 4°C. Lipid hydroperoxides were substantially formed in the fish muscles during the storage.

Comparison of techniques for monitoring waterborne mutagens: blue-rayon, Sep-Pak, and a biota, corbicula

Among 20 species of freshwater fishes examined, Pseudorasbora parva, Rhodeus ocellatus, Cobitis anguillicaudatus, Carassius auratus, Oryzias latipes, Gambusia affinis, and Gyrinocheilus anymonieri were found to drink water like seawater fishes, while 13 remaining species did not drink. For fish species found exclusively in fresh water, angiotensin II (AII) treatment did not induce drinking. In contrast, those freshwater fishes which survive in estuarine brackish water (Leuciscus hakonensis, C. carassius, Parasilurus asotus, G. affinis, Chaenogobius annularis, Tridentiger obscurus, and G. anymonieri responded to AII by drinking. Furthermore, some freshwater fishes which survive either in hypertonic water (C. auratus) or in sea water (Anguilla japonica and O. latipes) also responded to AII by drinking. Of 17 seawater fishes examined, Eptatretus burgeri, Triakis scyllia, and Heterodontus japonicus failed to drink water, and for Trachurus japonicus, Platichthys bicoloratus, and Glossogobius giuris fasciatopunctatus, water intake was minor (similar to freshwater fishes). The 11 remaining seawater fishes drank water. AII did not induce drinking in fishes living exclusively in sea water. However, seawater fishes which survive either in tide pools (Chasmichthys dolichognathus gulosus) or in brackish water (Sillago japonica, Mugil cephalus, G. giuris fasciatopunctatus) responded to AII by drinking. P. bicoloratus, Acanthopagrus schlegeli, and Fugu niphobles were exceptional, in that they survive in brackish water, but did not respond to AII. Although some exceptions exist, it is generally concluded that a drinking response to AII is characteristic of fishes which encounter water more hypertonic than that in which they typically reside. Accordingly, a drinking mechanism induced by AII may be a compensatory emergency reaction to dehydration stress.

Rapid and sensitive PCR detection of Vibrio trachuri pathogenic to Japanese horse mackerel (Trachurus japonicus).

A polymerase chain reaction (PCR) method was performed for rapid and sensitive detection of pathogenic Vibrio trachuri isolated from cultured Japanese horse mackerel. A set of primers was selected from the base sequence of the Pst I fragment of T9210 chromosomal DNA and used for PCR detection of T9210. This PCR specifically amplified the DNAs from V. trachuri T9210, T9213, and T9216 but not of those other bacterial strains. PCR using a Pst I-1 primer set made it possible to detect 100 fg of T9210 DNA. The PCR method reported here may be useful for detection and identification of V. trachuri pathogenic to Japanese horse mackerel.

Vibrio trachuri sp. nov., a new species isolated from diseased Japanese horse mackerel.

A new species, Vibrio trachuri sp. nov., was isolated from the cultured Japanese horse mackerel (Trachurus japonicus). These Vibrio were Gram negative, motile rods and formed yellow colonies on BTB teepol and TCBS plate, turned TSI medium to yellow and was sensitive to 150 microM O/129 (2,4-diamino-6,7-diisopropyl pteridine phosphate) like Listonella anguillarum which has been described as Vibrio anguillarum. However, the results of VP test and decarboxylation of lysine or dihydrolation of arginine suggested that these Vibrio are rather closely related to V. parahaemolyticus. DNA similarity determined by the microplate hybridization technique revealed that these Vibrio are genetically quite distant from Listonella anguillarum or V. parahaemolyticus and rather close to V. harveyi, although there was no Vibrio species which had more than 70% similarity value. From these results we propose to nominate Vibrio trachuri sp. nov. for this new Vibrio species.

小型定置網への魚群の入網時刻

In order to identify the entrapping time of fish into the set-net, experimental operations were conducted at a small scale set-net fishing area in Tateyama Bay, Chiba prefecture. The bag net was hauled up 6 times per day at 03:00, 07:00, 11:00, 15:00, 19:00 and 23:00 hours at 4 hour intervals. A total of 60 hauls at 6 different times of day were made and the catch was recorded for each species for studying the entrapping time of fish. Total catch was increased at the twilight time and the catch patterns of the main species were classified as the diurnal, nocturnal, crepuscular and aperiodic types. For example, the diurnal type included frigate mackerel Auxis thazard, the nocturnal type bottom perch Apogon semilineatus and flying fish Prognichthys agoo, and the crepuscular type round herring Etruneus teres and jack mackerel Trachurus japonicus.

Endurance and Muscle Lactic Acid of Swimming Jack Mackerel

The swimming endurance was measured in a flume tank at 20°C water temperature for 14.5-21cm long jack mackerel Trachurus japonicus. The endurance time (E. s) decreased drastically as the speed (U. BL/s) increased. An equation log E=-0.35 U+5.63 was derived. The maximum sustained speed of 6.2 BL/s was recorded for a 14.5cm fish. Swimming at 10.8 BL/s could not continue for more than 25 s for an 18.3cm fish. The concentration of lactic acid (mg per 100g wet muscle) in the red and white muscles of fish that swam at 78cm/s (4.2 BL/s) and 124cm/s (7.1 BL/s) was measured to compare with those of the control fish. In addition, the lactic acid change in the stages of 3, 12, and 24 h recovery after exhaustion was measured. The lactic acid concentration of the fish swam at 124cm/s increased to 176 and 486mg in the red and white muscles respectively, almost twice that of the control fish. The lactic acid concentration of the exhausted fish decreased to the same levels as the control fish in both muscle types after 3 h of recovery.

ストロボ光の威嚇効果に関する行動生理学的研究 Ｉ ストロボ光に対するマアジの回避行動

The avoidance response of the jack mackerel Trachurus japonicus to a strobe light barrier was investigated in the laboratory, by electrocardiogram measurement. The avoidance response varied with the strobe flash frequency (1.7-430 Hz) and strobe light intensity. Avoidance was greatest at flash frequencies of 5 and 10 Hz and clearly decreased as the strobe light intensity (15 Ix•s) was reduced. Heart rate increased when the fish stayed in the dark section of the tank or approached the barrier, but decreased when fish avoided or passed through the barrier or strobe light. Therefore, heart rate change can be used as an index of fish response to the effect of strobe light stimuli.

Effects of processing and storage on some chemical characteristics and lipid composition of a ghanaian fermented fish product

AbstractTo evaluate the effectiveness of the traditional method of processing in preservation of the final product, the changes in composition of lipids, free amino acids and organic acids of ‘momoni’, a Ghanaian fermented fish product, were investigated using Japanese jack mackerel (Trachurus japonicus) which is similar to African jack mackerel (Caranx hippos). The moisture content decreased drastically from 751 to 505 g kg−1 after fermentation for 3 days, and then remained almost constant during subsequent storage. Changes in pH were minimal although a gradual decrease was observed from 6·2 in the raw material to 5·9 after 2 months storage. Salt accumulation due to the salting process increased up to 325 g kg−1 but remained almost unchanged during subsequent storage. Volatile basic nitrogens (VBN) increased to 0·8 g kg−1 on a salt‐free dry matter basis, after 2 months storage. Most free amino acids, except histidine which was present in the highest concentration in the samples, increased during processing and subsequent storage. However, no detectable amount of histamine was formed after 2 months storage. Lactic acid, the most prominent organic acid (3·12 g kg−1 salt‐free dry matter) in the raw materials, decreased during processing and subsequent storage. Diphosphatidylglycerol, free fatty acids, and lysophosphatidylcholine increased appreciably. Processing resulted in depletion of sphingomyelin, phosphatidylserine and phosphatidylinositol with decreases in triglycerides, cholesterol, phosphatidylethanolamine and phosphatidylcholine. The proportion of the extracted total lipids present as polyunsaturated fatty acids decreased and this was accompanied by increases in the proportions of saturated fatty acids, indicating a high degree of oxidation. Peroxide value and thiobarbituric acid value increased on fermentation, confirming the observed oxidation, but decreased during storage. In conclusion, although oxidation was extensive, following hygienic and good manufacturing practices, this simple method could prevent spoilage taking place in fish if good‐quality raw materials are used.

Red and White Muscle Activity of the Jack Mackerel Trachurus japonicus During Swimming.

In order to examine the functions of the red and white muscle of jack mackerel Trachurus japonicus during swimming locomotion, the fish was dissected to observe muscle distribution along the body. The electrical activity of the lateral muscle was analyzed using an electrophysiological technique. The ratio of red muscle to total muscle in a transverse section of the fish body reached a maximum at a position between 55% and 65% of fork length from the snout. The red and white muscles accounted for 5.1% and 61% of the body weight respectively. The white muscle was 12 times as heavy as the red muscle. In the electromyographic observations, the red muscle was active in sustained swimming at low speeds, whereas there was no electrical activity from the white muscle at speeds below 108cm/s for fish of 17.8cm in fork length. The bursts of discharge appearing in the electromyograph were measured for three components: frequency, amplitude, and duration. The frequency increased in proportion to swimming speed in both muscles. The tendency for the amplitude to increase with swimming speed was much more remarkable in the red muscle than in the white muscle. The duration in the red muscle decreased, whereas in the white muscle it rose with the swimming speed. The results indicate that for jack mackerel only the red muscle is used in sustained swimming, while the white muscle is used during burst swimming above a threshold speed of 6.4BL/s, together with red muscle.

定置網漁場における魚群の移動行動

The migrating behaviour of fish schools such as jack mackerel Trachurus japonicus, spotted mackerel Scomber australasicus, and Japanese anchovy Engraulis japonicus was investigated in set-net fishing grounds by means of sonar image records. The spotted mackerel and Japanese anchovy schools moved at an average speed of 18-19cm/s, while the jack mackerel schools moved at 29cm/s. Schools of all species changed their direction of movement at an average veering angle of 19 ?? 36°. However, the veering angle of Japanese anchovy schools showed a tendency to be larger than that of the other two species. The average duration of straight movement of the spotted mackerel and Japanese anchovy schools was 2 ?? 2.4min, while that of the jack mackerel schools was 2.9min. This confirms a frequent veering of fish schools in the set-net fishing grounds. The jack mackerel and Japanese anchovy schools tend to move along the isobathic route with a depth change ratio of 0.6 ?? 0.8m/min between the first and final image. In case of the spotted mackerel schools the larger depth change was observed up to 6m/min.

気泡幕による魚群の行動制御に関する研究 ＩＩ 大型円形水槽内における気泡幕の魚群駆集効果

The herding effect of an air bubble curtain was examined for jack mackerel Trachurus japonicus in a 2m wide annular trough set in an outdoor tank of 7m diameter. Sixteen air pipes were radially arranged on the bottom at the same interval. The bubbling position can be alternated in order by the valve switches which are connected to the air blower. Group of 10 fish swam away from the bubbling position, and were successfully herded by the position movement of the air bubble curtain to keep going around in the trough. The fish response was observed with varying bubbling intervals of 1, 2, 3, 5, and 10 seconds in daytime and nighttime. Bubbling intervals were equivalent to 7.9-79cm/s or 0.5-5.4 BL/s of the fith swimming speed. In the case of intercepting the trough by a sheet of netting or air bubble curtain, fish was herded toward the stationary barrier, and concentrated just in front of it. This experimental result can be applied to the practical fish capturing methods, such as the set-net, by herding fish into the final trap without net hauling procedures.

気泡幕による魚群の行動制御に関する研究 Ｉ 小型水槽内における気泡幕の魚類駆集効果

In order to develop a new method for the control of fish behaviour, the authors observed the response of fishes to an air bubble curtain by laboratory experiments. An annular trough set up in a small scale test tank was intercepted by the air bubble curtain, which was rotated along the trough. The response toward the air bubble curtain of Japanese parrotfish Oplegnathus fasciatus, jack mackerel Trachurus japonicus, and threeline grunt Parapristipoma trilineatum were observed with the variation of moving speed (11.0-31.7cm/s) and air flow (3-12l/min). The results show the typical herding effect of the moving air bubble curtain, as the fish keep swimming in escaping from the bubbles with a possible herding time of one hour in some specific conditions. The herding effect, however, varies with experimental species and condi-tions, and is lowered with the habituation of fish kept in an air bubbled tank.

光束断続光を利用したマアジの行動制御

Utilizing the fact that the horse mackerel Trachurus japonicus, has an outstanding aversion for specific intermittent light, it has been elucidated through a series of experiments that the passage of a fish school can be blockaded or a fish school can be trapped into an enclosed site. In this investigation, the intermittent light was used as a beam, and a certain number of beams were projected at once. Under adaptation to dark conditions, the passage of the fish school was completely suppressed when the ratio of light intensity between light beams and background was more than 83:1, and the space between the beams was less than 50 cm. However, under light adaptation, suppression of passage required a ratio of more than 60 times that needed under dark adaptation. It has additionally been confirmed that such a suppressional effect as discussed was sustained for more than 100 hours without necessitating any changes in conditions of intermittent light beams.

マアジの摂餌刺激物質に関する研究―ＩＩＩ マアジに対する核酸関連物質およびトリプトファン関連物質の摂餌刺激活性

The feeding stimulant activities of nucleotides-related and tryptophan-related componunds were tested on young jack mackerel Trachurus japonicus at concentrations of 1 and 5 mmol/100g dry diet, respectively. Effective doses of inosine 5'-monophosphate (IMP) and L-tryptophan (Trp) added to the diet on feeding activity were also examined. Of 33 compounds tested, IMP, guanosine 5'-monophosphate (GMP), uridine 5'-mono-phosphate (UMP), UDP, UTP, and Trp were effective. Hipoxanthine, nucleosides (inosine, adenosine, guanosine, uridine), nucleotides including adenosine 5'-monophosphate (AMP), ADP, ATP, IDP, ITP, GDP, GTP, xanthosine 5'-monophosphate, 3'-IMP, 3'-UMP, 2-deoxy-IMP, allyltio-IMP, and Trp-related compounds (D-Trp, DL-Trp, 5-hydroxy-Trp, 5-methyl-DL-Trp, tryptamine, 5-hydroxy-tryptamine, indolepropionic acid, indole-3-pyruvic acid, β-indolelactic acid, indole) were all ineffective. These results suggest that the molecular structure of 6-hydroxy-or 2-amino-6-hydroxy-purine riboside-5-phosphate is required for feeding stimulation toward jack mackerel, and that the activity of Trp was lost by a chemical modification of the molecule. The minimum concentrations of IMP and Trp needed to show the maximum effect were estimated as 0.8 and 5 mmol/100g dry diet, respectively.

Immunoreactive atrial natriuretic peptide in the fish heart and blood plasma examined by electron microscopy, immunohistochemistry and radioimmunoassay

The immunoreactivity of atrial natriuretic peptide and ultrastructure of cardiocytes were examined in 5 species each of freshwater and seawater teleosts, as well as in 2 species each of elasmobranchs and cyclostomes. Immunoreactivity was strong in the atria of Cyprinus carpio, Anguilla japonica and Conger myriaster, rather weak in atria of Channa maculata, Lepomis macrochirus, Salmo gairdneri, Oplegnathus fasciatus and Eptatretus burgeri, very weak in atria of Pagrus major, Trachurus japonicus and Triakis scyllia, and not detectable in atria of Hexagrammos otakii, Narke japonica and Lampetra japonica. The immunoreactivity of the atrial cardiocytes was generally stronger in freshwater than seawater fish. Ventricular immunoreactivity was detected only in 7 species, always being weaker than that observed in the atrium. Ultrastructurally, however, secretory granules were found in atria and ventricles of all species examined, being more frequent in the former than the latter. By radioimmunoassay, immunoreactive ANP was detected in the extracts of blood plasma and both atrial and ventricular tissues of all species examined. There were no statistically significant differences in the values between freshwater and seawater species.

Body characteristics of Peruvian jack mackerel Trachurus symmetricus murphyi to determine the mesh size of nets.

Fundamental body characteristics of Peruvian jack mackerel and approximation of girth were studied to determine the mesh size of nets in the future. On specimens collected off the coast of Callao-Peru, the girth, height and breadth at both maximum position (suffix “m”) and operculum position (suffix “o”), weight and fork length were measured. The relationships of girths (Gm, Go), heights (Hm, Ho), breadths (Bm, Bo) and weight (W) for fork length (L) were presented as Gm/L=0.511, Hm/L=0.188, Bm/L=0.125, Go/L=0.483, Ho/L=0.169, Bo/L=0.118 and W/L3=0.113×10-4. Assuming the girth as a circumference of an ellipse, approximation of girths (Gm, Go) was attempted using maximum height (Hm) and maximum breadth (Bm). The approximation obtained could be used with high precision. The body characteristics of Peruvian jack mackerel is nearly similar to that of large-size Japanese jack mackerel.