All issues
Volume 23, Issue 6
Displaying 1-10 of 10 articles from this issue
- |<
- <
- 1
- >
- >|
-
Sexual Difference in the External Shape of the ShellNenosuke KOTAKE, Mitsuyasu KAWAMURA1957 Volume 23 Issue 6 Pages 287-289
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSSexual difference in the external shape of the shell of the pearl oyster Pinctada martensii has been investigated. The materials used for this investigation were 3 or 4-years old bivalves, which were collected at the coast of Hiwasa, Tokushima Prefecture. The dimensions in the length of shell (L), in the height of shell (H) and in the length of hinge line (hi) were measured respectively as shown in Fig. 1. The sexes were determined anatomically, being exactly ascertained their gonads.
As the result of measurement, Fig. 2 indicates the frequency polygon of each sex, in the dimensions of L/H×100 and hi/H×100. The distributions are supposed to be normal frequency curves (Table 1). The curves of the relative growth (L/H) are shown in Fig. 3. In these two figures, the male type of shell is not clearly different from the female one. On the other hand, the three types of shell (L>H, L<H and L=H types) are distinguished without regard to both sexes, as shown in Fig. 4. And, in these three types, the percentages for the male shells are always higher than those for the female ones (Table 2). Therefore, it is difficult to distinguish the sexual difference in the external shape of the shell.View full abstractDownload PDF (168K) -
The Rôle of Calcium Ions in Fertilization and DevelopmentRyuzo YANAGIMACHI1957 Volume 23 Issue 6 Pages 290-294
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESS(1) Ca ions play an extremely important rôle in the fertilization of Clupea eggs. When the eggs are repeatedly washed in an isotonic Ca-free Ringer's solution (M/4.5 NaCl 100 parts+M/4.5 KCl 3.5 parts+M/6.7 MgCl2 2.4 parts, pH 7.6 by NaHCO3) and inseminated in such a solution, not a single one is fertilized. However, if a few drops of CaCl2 solution are added to this solution, all the eggs are fertilized at once, In one experiment, the eggs and sperm were kept overnight in the Ca-free Ringer's solution. The next morning all the eggs were intact and not a single one was fertilized. At that time a few drops of CaCl2 Solution were added to this solution and instantly all the eggs were fertilized and began to cleave at the proper time. Thus the fertilization of the Clupea egg is closely dependent on Ca ions in the surrounding medium.
It has been found that the failure of fertilization in the Ca-free Ringer's solution results from the fact that the spermatozoa fail to enter the micropyle. As pointed out previously (YANAGIMACHI'57: Zool. Mag. 66; Bull. Jap. Soc. Sci. Fish. 23), the Clupea spermatozoa are rendered extremely active in the micropyle area of the mature egg. When Ca ions are lacking in the surrounding medium, the spermatozoa are not activated: the spermatozoa are quiescent even if they are brought to the micropyle area of the egg, so that not a single spermatozoon enters the micropyle. It is only when a sufficient amount of Ca ions is present in the medium, that the spermatozoa are activated and enter the micropyle.
It has been shown that Mg ions can be substituted for Ca ions, though the former must be in higher concentration than the latter. Data on fertilization of the eggs in the solutions containing various amounts of Ca ions and Mg ions are shown in Tables 1 and 2.
(2) Ca ions are necessary for parthenogenetic activation of the eggs. When the eggs are repeatedly washed in the Ca-free Ringer's solution and pricked with a fine glass needle, not a single egg is activated. The same is true when the eggs are treated with an isotonic solution of sodium oxalate (a Ca precipitant) for 15 minutes or longer. When such eggs are transferred into the isotonic Ringer's solution containing Ca ions, all the eggs are instantly activated without further pricking. Thus, the activation by pricking seems to depend on the presence of Ca ions.
The eggs are also activated by chemical agents, such as saponin. In this case, too, the presence of Ca ions in the surrounding medium is of essential importance.
(3) The eggs once fertilized are able to cleave in the Ca-free Ringer's solution. However, blastomeres tend to pull apart from each other (Fig. 1). This is probably due to the dissolution. of the so-called “surface gel layer”.View full abstractDownload PDF (336K) -
Tamotsu IWAI1957 Volume 23 Issue 6 Pages 295-301
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESS1. The embryos of the luminous shark, Etmopterus Lucifer J. et SN., are provided with the yolk duct lying between the yolk sac and the duodenum. Yolk may be taken up directly by the gut of embryo during the development through this duct, although it of course is also absorbed through the vitelline capillaries.
2. The internal yolk sac which organized by inflation of the posterior part of the yolk duct, is first established in the abdominal cavity of the embryo measuring approximately 60mm., and is still retained after the external yolk sac has disappeared.
3. The duration of the gestation period of this shark appears to be about one year.View full abstractDownload PDF (1463K) -
Nacreous Layer PearlKozi WADA1957 Volume 23 Issue 6 Pages 302-305
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSSections of nacreous layer pearls cultured in Pinctada martensii (DÜNKER) were observed with electron microscope and the results were as follows:
1. Very thick conchiolin layer often deposited on surfaces of nuclei and small crystal grains were sometimes contained in the layer. These grains are considered as calcite.
2. In rare occasion, there were no deposition of thick conchiolin on surfaces of nuclei and nacreous layers, composed of aragonite and conchiolin, deposited directly on them.
3. Some pearls have three successive layers, -periostracum, prismatic and nacreous layers.
4. Thick conchiolin layers were also found in nacres, whose structure were different at above and below the layers.View full abstractDownload PDF (1350K) -
On the Physico-Chemical Changes of Agar and its Intermediate Product, “Tokoroten” in the SpoilageHiroaki FUJISAWA, Terutake SUKEGAWA1957 Volume 23 Issue 6 Pages 306-314
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSThe “tokoroten” (gelidium jelly) which is an intermediate product during the manufacturing process of agar is often spoiled in the mild winter, and subsequently the quality of agar manufactured is depressed. This is called the “dankan” phenomenon.
In the present paper, the authors examined both organoleptic and physico-chemical changes of “tokoroten” during spoliage and the effect of spoilage on the quality of agar prepared. The results obtained are as follows:
(1) Physico-chemical properties of “tokoroten” change largely during the progress of spoilage and the quality of agar prepared is affected by these changes; the reducing sugar increases slowly but the relative viscosity and the jelly strength decrease rapidly during spoilage (Table 3, 4, 5 and 6).
As these changes especially the latter two parallel with that of organoleptic observations, it is assumed possible to assign three grades for the spoilage in terms of the ratio of relative viscosity to jelly strength (Fig. 5).
(2) Some causative microörganisms in the spoilage were separated from spoiled “tokoroten”, agar and other materials. They were chromobacteria producing red, orange, yellow and yellowish orange pigments, and one of them was an agar-decomposing bacterium. It is inferred that these bacteria are substantially derived from the tainted reed mat on which “tokoroten” is laid.
Therefore, it is necessary for the manufactures to sterilize the reed mat by any means in order to prevent “tokoroten” from spoilage in the mild winter.View full abstractDownload PDF (3196K) -
Tadashi TAWARA, Yûichi SASANO1957 Volume 23 Issue 6 Pages 315-319
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESS1. In the previous report, the authors found that the activity of chlorotetracycline (CTC) is reduced in the service water and suggested that the active chlorine in the water might be responsible for it. The hypothesis is tested in the present study.
2. Both iron and calcium, at their levels in the service water respectively, did not affect the activity of CTC. Since CTC was stable also in the sea water, it might be safely inferred that not only iron and calcium but the metals present in the service water do not affect CTC.
3. The use of the service water, which was previously added with some chlorine consuming substances such as vitamin C, Na-nitrite, Na-sulfite, citric acid or tartaric acid made it possible to prevent the decrease in CTC activity. Among these substances, vitamin C, Na-nitrite, Nasulfite, and Na-thiosulfate were more effective in removing the active chlorine than citric acid or tartaric acid. These acids, especially the latter is slow in the reaction with the chlorine, which needs the light-treatment.View full abstractDownload PDF (369K) -
Teizo MARUICHI, Yoshiaki HINO1957 Volume 23 Issue 6 Pages 320-323
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn the process of manufacturing a round dried fish, the fish growes often “musty” in the warm season.
After the previous paper, it has now been studied the effect of meteorological conditions on the body temperature in the process of drying, as it is presumed to exist some relations between the musty character and the temperature of fish.
The results obtained are as follows:
1. The body temperature of a round fish grows usually heigher than that of a split- or boiled- fish in the early stage of drying as shown in Figs. 1-4.
2. The temperature of fish viscera rises above that of the flesh in out-door drying (Tables 1-2).View full abstractDownload PDF (303K) -
Seborrhea Forming Activity of Esters of Fatty Acids with Higer Alcohols upon the Rats (2) Preventive Methods of SeborrheaTakashi KANEDA, Hisae SAKAI, Seinosuke ISHII1957 Volume 23 Issue 6 Pages 324-330
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn the previous paper2) dealing with the seborrhea forming activity of sperm whale oil or the esters of fatty acids with higher alcohols as oleyl oleate, it was observed that the rats fed with the above lipids contained large amounts of unsaponifiable matters in viscera and muscle.
In the present study aiming at finding a preventive method of seborrhea disease, the authors obtained the following results:
(1) The rats fed with sperm whale oil were found containing in their body hydrocarbons 150 times and sterols five times as much as those in normal rats (Table 1).
(2) Experiments on various preventive methods of seborrhea have revealed that some of them are not so effective to prevent seborrhea formation as they have been believed so for a long time. However, adding of phospholipids of soy bean to the basal diets showed good effects for the prevention of seborrhea (Table 2).
(3) On the basis of these findings, when the lecithin and cephalin fraction separated from the soy bean phospholipids were compared in the preventing effect, it became clear that the latter exerts a good effect, while the former no effects, to the rats (Table 3-6).
(4) The above results are suggestive of this. As far as the present study is concerned, it is not the genuine cephalin but the crude one that shows protective effect from the seborrhea for the rats fed with sperm whale oil or oleyl oleate. Because when the cephalin fraction was prepared by treatment with solvent extraction, it was likely contaminated with some other substances.View full abstractDownload PDF (1189K) -
Kiyoshi FUKUSHIMA, Takeaki KIKUCHI, Isami OSAKABE, Ikunosuke OKADA1957 Volume 23 Issue 6 Pages 331-334
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIn the polarographic studies of glutathione involved in marine products, the authors found a new polarographic reduction wave. This polarographic reduction wave has a half wave potential of nearly -1.25 V vs. S. C. E. in McIlvaine's buffer soln. of PH 7.0.
In this paper we examined the charcteristics of this reduction wave, and the following results were obtained.
1) The reduction wave was observed only in the muscles of mollusca and crustacea and not in common fish flesh. (Fig. 1 and 2)
2) The substance responsible for reduction wave was found to be readily soluble in water and insoluble in ether, and it was stable to heat (100°C) and had no volatility. (Fig. 3)
3) The potential of this wave was effected by the pH value of the electrolytic soln. and shifted to the positive side according to the decrease of the pH value (Fig. 4)View full abstractDownload PDF (254K) -
Confirmation and Determination of Radioactive Elements in Contaminated Fishes Caught in 1956 (Part 1)Harumi TOZAWA, Yoko TOKUE, Keishi AMANO1957 Volume 23 Issue 6 Pages 335-340
Published: October 25, 1957
Released on J-STAGE: February 29, 2008
JOURNAL FREE ACCESSIt has been already published that radioactive elements such as an Zn65, Fe59, Fe55 were contained in some organs and tissues of fishes contaminated by the test of nuclear explosion at Bikini Atoll in 19541, 2).
The present paper deals with radiochemical analysis that was carried out for the confirmation and determination of radioactive elements contained in the liver of a yellow-fin tuna and in the muscle of a big-eyed tuna caught at the station near 10°N, 157°30'E by the research vessel, “Shunkotsu-Maru”, on her second expedition to the Bikini area in June 1956.
The cathionic resin method previously reported were applied to separate the radioactive elements contained in the yellow-fin tuna, and the radioactivity was found mainly in the fraction eluted with 0.5% oxalic acid or 5% ammonium-citrate. In the latter, the elements were effluented at pH 4.1 and 4.6 (Fig, 1). Then, the radioactive fractions were treated with an anionic resin (Dowex 1) and the elements were separated again with the various concentrations of hydrochloric acid (Figs. 3, 4, 5). According to the measurements of decay and absorption curves of the radiations emitted from the elements, it has been confirmed that the elements are Fe55, a mixture of Zn65 and Fe55, and Cd113m. The last element, Cd113m, it is assumed from the results, is the same that was found in the liver of the skipjack caught in 1954 and reported as unidentified element on the previous occassion, But Fe59 detected from the skipjack was not contained in the present samples.
It is calculated on the basis of our experimental conditions that radioactivties of Fe55 and Zn65 in 100g of the liver of the yellow-fin tuna were about 0.1μc and 0.004μc respectively, but the activity of Fe55 in the muscle of the big-eyed tuna coincided with 0. 004μc per 100g of the tissue.View full abstractDownload PDF (321K)
- |<
- <
- 1
- >
- >|