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Volume 26, Issue 4
Displaying 1-14 of 14 articles from this issue
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SPECIES OF FISHES ATTRACTED TO BAMBOO RAFTSShumpei KOJIMA1960 Volume 26 Issue 4 Pages 379-382
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSDuring the months from June to October “Shiira-zuke” fishery is operated off Shimane Prefecture on the Japan Sea coast with help of bamboo rafts serving as floating shelters for the dolphin, Coryphaena hippurus, and other fishes. (For construction of the raft see KOJIMA, 1956. Bull. Jap. Soc. Scien. Fish., 21: 1049 ?? 52). In catching fish gathering around the shelters purse seines are used. The present work deals with relative importance of catches by species and individual size on the basis of the data made available for the 1955-58 seasons.
In Table 1 the amount of landings from four fishing units is indicated by species and month. As the fishing season lasts from early summer till autumn, a majority of catch is represented by warm-water species. Of the total weight of the annual catch, the dolphin occupied 93-96 percent, the rest being composed of such species as Seriola, filefish (Monacanthus cirrhifer), and hardtail (Caranx helvolus). Each of them seems to occur in almost the same months every year under study. As skipjack and tunas can not be caught by purse seine, their catches as in Table 1 must have been made by angling during the trip from one shelter to another.
Numbers of individuals sampled from “shiira-zuke” catches at various ports were identified as to species, and the total length of them measured as in Table 2. In a report by previous workers the size of fish following drifting seaweed was noted. They were smaller in size than those observed in the present work. Differences in the size of fish are attributable to the fact that the former group of fish following drifting substance is too small, while the latter staying with the bamboo shelter kept at a point is large enough, to resist the current.View full abstractDownload PDF (220K) -
BEHAVIOURS OF FISH GATHERING AROUND BAMBOO RAFTSShumpei KOJIMA1960 Volume 26 Issue 4 Pages 383-388
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSBehaviours of the dolphin (Coryphaena hippurus L.) and other fishes taking shelter around bamboo rafts were observed at sea off Hamada, Shimane Prefecture during the 1955-58 seasons. The observations on which the present report is based were made on board a commercial fishing boat, by trolling fish during oceanographic surveys, or by diving under a bamboo shelter. The following are essential results thus obtained.
1) All the fish attracted to the shelter were found staying in parallel with it. Most of them were centering either around the anchor line or at the head of the raft held against the current, but very few were at the tail of the raft.
2) In an underwater observation carried out in the daytime, the shadow of the raft was not so visible as it was from above the surface. Therefore, the area of the shadow assumed from the positions of the sun and the raft was compared with the distribution of fish around the shelter. The result revealed that a particular part of the shelter attracting fish was more dependant on the direction of the current than on the position of the shadow.
3) Among the various species swarming about the raft, the smallest was “mejina” (“Girella punctata” Gray) of about 5cm. in length. When the author held out the hands to scare them, they fled away a little from the shelter but soon returned there again, without being driven off by the current. From that finding it may be feasible to consider that fish staying at the shelter are those having grown enough to, resist against a normal speed of the current (Fig. 3). When the current was unusually fast, however, a very few dolphins, and still less the others, could apparently stay with the raft.
4) At night a lamplight held alongside the shelter was successful in getting dolphins to come out of the shelter. Seemingly the fish would stay under the shelter overnight.
5) In vertical distribution along the anchor line, the larger the size of fish, the further they stayed away from the raft. Tendency in the horizontal distribution appeared nearly si-milar but was not so clear as in the vertical pattern (Fig. 4).View full abstractDownload PDF (449K) -
TROPISM IN GROWTH DIRECTIONEizi OGATA1960 Volume 26 Issue 4 Pages 389-392
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIt was successively observed how the Conchocelis germlings grew in the shells which were faced sidewards in culture vessel.
The germlings spread the filaments inwards far off from the shell surface. Accordingly they tend to run horizontally at a right angle to gravity.
When the shells were laid in a prone position, the filaments also grew into inner layer of shells receding from their surfaces. Namely, they run upwards against the gravity.
Anastomosed filaments always throve in the close layers which run parallel to the shell surfaces having no connection with the direction to which their surfaces were faced.
Generally speaking, gravity shows no influence on branching and growth in Conchocelis filaments.View full abstractDownload PDF (1271K) -
EFFECTS OF SOME ENVIRONMENTAL FACTORS ON THE VERTICAL GROWTHEizi OGATA1960 Volume 26 Issue 4 Pages 393-396
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSGrowth rate in Conchocelis-filaments under some environmental conditions has so far been examined measuring the elongation of main filaments only for horizontal direction in shell matrix.
In this paper the elongation of filaments for vertical direction besides for horizontal direction was measured in order to elucidate the effects of light intensity and sea water concentration on the growth rate. Results are as follows:
1. It seems that the vertical filaments grow most rapidly under 2000 lux irradiation. But these cease to grow under the irradiation less than 5 lux. (Fig. 2, a; Fig. 2').
2. In half diluted sea water, the vertical growth is a little worse than in the normal. Such filaments cultured in extremely concentrated (twice) or diluted (one eighth) sea water show no more elongation for vertical direction (Fig. 3, a).
3. Under the identical experimental conditions, both growth rates for vertical and horizontal directions scarcely show large gaps in the trends obtained in experiments (Fig. 2, a•b; Fig. 3, a•b).View full abstractDownload PDF (918K) -
Yasushi KONDO1960 Volume 26 Issue 4 Pages 397-400
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe object of this study is to measure tension of the netting cord by impact test using strain gauge. The netting cords composed of short fibers and of endless filaments were used.
The results obtained were as follows:
1) The breaking strength of the netting cord obtained by impact test is constant independent with the impact force. Regarding to the short fibers cord, breaking strength obtained by impact test are larger than those obtained by static test, respectively. For the endless filaments cord, it is whether same tendency or the formers are smaller than the latters.
2) The breaking elongation obtained by impact test are smaller than those obtained by static test.
3) The breaking energy of the short fibers cord obtained by impact test are larger than those obtained by static test. For the endless filaments cord, it is whether same tendency or the formers are smaller than the latters.View full abstractDownload PDF (310K) -
ON THE ANNUAL VARIATION OF FISHING CONDITIONJun NAKAGOME1960 Volume 26 Issue 4 Pages 401-402
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe author studied on the annual variation of fishing condition of bigeyed tuna of an area of the Pacific Ocean spreading from Marshall Islands to Palmyra Island.
The rate-of-catch (catch number per one hundred hooks) of bigeyed tuna in that area was considerably high in 1952, declined in 1953, declined a little in 1954 and 1955, declined very much in 1956, increased very much in 1957, increased a little in 1958 and again declined a great deal in 1959 (Fig. 1).View full abstractDownload PDF (90K) -
COMPARISON BETWEEN 1956 AND 1958 IN REGARD TO FISHING PERIOD AND FISHING GROUND AND RELATION BETWEEN FISHING CONDITION AND FISHING EFFORTJun NAKAGOME1960 Volume 26 Issue 4 Pages 403-405
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe author made a comparison between the fishing period and fishing ground of bigeyed tuna in the area from Marshall Islands to Palmyra Island of 1956 (poor catch year) and that of 1958 (high catch year), and studied on the relation between the fishing condition and the number of fishing gear used.
1) The rate-of-catch (catch number per one hundred hooks) from December of 1957 to March of 1958 was higher than that of 1955 ?? '56. Namely, good fishing of 1958 was brought by higher rate-of-catch in December-March of 1957 ?? '58 (Fig. 1-A).
2) Good fishing of 1957 ?? '58 was brought forth also by use of more fishing gear in December-March of 1957 ?? '58 year than in the months of 1955'56 (Fig. 1-B).
3) Rate-of-catch by latitude and by longitude in 1958 were higher than those in 1956. But no specific inclination by latitude and longitude is noticeable in the distribution of the rates-of-catch of 1958. Namely, good fishing of 1958 was brought forth by higher rate-of-catch in the whole area (Figs. 3 and 4-A).
4) Good fishing of 1958 was hardly influenced by any specific inclination in the number of fishing gear used (Figs. 3 and 4-B).
5) Accordingly it is presumed that the annual variation of the fishing condition was brought about by variation of the rate-of-catch of the whole area, particularly at best fishing season, though it might have been somewhat affected by some inclination in the catch effort.View full abstractDownload PDF (226K) -
RELATION BETWEEN MONTHLY AND ANNUAL VARIATIONS OF FISHING CONDITION AND THOSE OF SURFACE WATER TEMPERATURE OF THE FISHING GROUNDJun NAKAGOME1960 Volume 26 Issue 4 Pages 406-407
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe author studied on the direct relation between monthly and annual variations of fishing condition of bigeyed tuna and those of surface water temperature in the area of lat. 5-15°N, and long. 160-180°W.
1) The surface water temperature in average by month was low (26-27°C) in the first half of a year and was high (28-29°C) in the latter half (Fig. 1).
2) The rate-of-catch (catch number per one hundred hooks) was high in the period (the first half of year) when the surface water temperature was low (Fig. 1).
3) The rate-of-catch and the surface water temperature vary annually, however, the direct relation between them could not be seen (Fig. 2).View full abstractDownload PDF (120K) -
RELATION BETWEEN ANNUAL VARIATION OF RATE-OF-CATCH AND THE THAT OF BODY-LENGTH OR OF AGE FREQUENCYJun NAKAGOME1960 Volume 26 Issue 4 Pages 408-410
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe author studied if there should be any relation between annual variation of rate-of-catch and that of body-length or of age frequency.
1) Annual variation of rate-of-catch did not relate directly with that of body-length frequency.
2) Annual variation of age frequency had a relation with that of rate-of-catch. It is presumed that the latter was based on the former, especially appearance of a dominant age group.View full abstractDownload PDF (131K) -
QUANTITATIVE ANALYSIS OF UNSATURATED FATTY ACID BROMIDESHideo HIGASHI, Yaichiro SHIMMA, Hisako TAGUCHI1960 Volume 26 Issue 4 Pages 411-420
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSMany studies on the fatty acids of the marine animal livers have been done usually by the distillation of fatty acid esters extracted from high oil content livers. However, little effort has been made for quantitative determination of unsaturated fatty acids in low oil content livers. Kinds of animals used for the present study include bluefin tuna, bigeyed tuna, Indian tuna, Skipjack, fur-seal and fin whale. Free fatty acid and oil were extracted from the livers which had been minced and stored at about -10°C for 1 ?? 2 months. By saponifying the liver oil, mixed fatty acid which had formed glycerid and esters with vitamin A, sterol and other unsaponifiable alcohols, were separated from other components. In order to differentiate two groups of fatty acids, the authors propose to call the former “free type of fatty acids” (FFA) and the latter “ester type of fatty acids” (EFA). On each of the two types of fatty acids, iodine value and neutralisation value were determined (Table 3). Each of them was treated with lead acetate in 95 % alcohol, and separated into solid acid (SA) and liquid acid (LA). After brominated, the latter was separated into four fractions: oleic, linoleic, linolenic and arachidonic acid fractions, by making use of difference of solubility for petrol ether, ether and chloroform (Tables 2 and 4).
The results of our experiments were as follows
1. During a long storage, glycerid was destroyed by the lipase in the tissues, but esters of unsaponifiable matters seemed to be hardly attacked by the enzyme (Table 1 and Fig. 1). Then in low oil content livers such as under report, unsaponifiable contents in the extracted oils ran up to 30 ?? 50 % (Table 3).
2. In those fish livers, SA content has been found 22 ?? 27 % in EFA and 24.2 ?? 35.5 % in FFA. The sum of SA and oleic acid was 61 ?? 76 %. Between the two types of FA, percentage of each other unsturated FA was almost the same. Accordingly it may be concluded that a greater portion of FA which forms esters with such unsaponifiable matters as vitamin A and sterols must be composed of oleic acid and SA likewise in glycerid (Table 4).
3. In fin whale, SA was found 41.4 % in FFA and 15.1 % in EFA, whereas in a specimen of fur-seal (B) it was 20.2 %-16.5 % in each type of FA. But the constitution percentages of unsaturated FA of the marine mammals were similar to those of fishes, with the sum of SA and oleic acid being also 61 ?? 76 %. However, the fur-seal (A) had an embryo and exceptionally low content of highly unsaturated FA. Some kinds of vitamins in the liver of fur-seal (A) and (B) were determined (Table 5).View full abstractDownload PDF (1326K) -
SPHINGOLIPIDS OF DARK-COLORED AND ORDINARY MUSCLESMuneo KATADA1960 Volume 26 Issue 4 Pages 421-424
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSSphingolipid preparations obtained from the dark-colored and ordinary muscles of a tuna, Thynnus orientalis, respectively gave eight fractions by chromatography on silicic acid eluting with chloroform/methanol.
These were found to be six galactosphingosides (monoacylgalactosylsphingosine), a sphingomyelin (monoacylsphingosylphosphorylcholine), and a lipid having a galactose-sphingosine-nitrogen molar ratio of 1:1:2.View full abstractDownload PDF (244K) -
DISTRIBUTION OF LIPIDS IN DARK-COLORED MUSCLE, ORDINARY MUSCLE, AND SEVERAL OTHER TISSUESMuneo KATADA, Koichi ZAMA, Hisanao IGARASHI1960 Volume 26 Issue 4 Pages 425-429
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSDistribution of lecithin, phosphatidylethanolamine, phosphatidylserine, acetal lipid, sphin-gomyelin, cerebroside, and cholesterol in various parts of the dark-colored and ordinary muscles and several other organs of a tuna, Thynnus orientalis was determined with the results presented in Table 1 and 2.
In the external parts of dorsal, ventral, and dark-colored muscles, the content of total lipids, iodine numbers of the lipids, and the ratio of total-phospholipids/cholesterol were found to be higher than those of the internal parts.
A similarity in lipid constitution was observed between the internal dark-colored muscle and liver.View full abstractDownload PDF (290K) -
Sang CHOE1960 Volume 26 Issue 4 Pages 430-437
Published: 1960
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe tube-dwelling bristle-worm, Diopatra neapolitana which lives in sand occupying a parchment-like tube is found in common in the tidal flat along the coast of inland seas and frequently is used as a bait. The tube of this worm is characterized by the presence of fragments of shells or sea-weeds and other debris adhering to its upper part, which projects above the surface of the sand.
The present study was undertaken to secure information concerning on the life history of this worm, viz., breeding season, development, metamorphosis, growth and age etc. For this purpose observations and measurements were made of worms collected in 1955-1956 from the coast of Maeshiba and Umeyabu, Toyohashi City, Aichi Prefecture. Attempts were also made with success to inseminate the egg of this worm artificially and to culture the larva. The results obtained are summarized as follows:
1) The sexes are seperated and no external morphological difference can be detected between them. In the breeding season, however, they can be distinguished each other by the gonad color externally observable through the body wall. The breeding season lasts from June to early September, with the peak spawning in mid-July and early August.
2) The immature ovarian egg has two strings of nurse-cells which fall off as the egg matures. The matured egg has a diameter of approximately 200 microns.
3) About 13 hours after fertilization at 27.0-29.5°C, the embryo becomes a free-swimming protrochophore larva. After about 3 days the free-swimming larva grows to 0.5mm in body length and sinks to the bottom. About a month after settling, the worm reaches 3-8mm in body length.
4) Judging from the shifts in the modes found on the body-weight frequency distributions of the worms collected from the field, this worm seems to grow as follows:
Age 1 yr. 2 yrs. 3 yrs.
Total body length (cm) 12.4-13.9 21.1-23.2 28.5-31.7
Total body weight (gr) 1.3-1.7 3.4-4.0 5.7-6.3
5) The relation between the total body weight (W gr) and the total body length (L cm) is given by a formula, W=0.0184L1.6799.View full abstractDownload PDF (1330K) -
1960 Volume 26 Issue 4 Pages 442
Published: 1960
Released on J-STAGE: April 22, 2008
JOURNAL FREE ACCESSDownload PDF (43K)
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