-
Kazuhiko SUDO, Hideaki NAKATA
1995 Volume 43 Issue 1 Pages
1-9
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
In order to clarify the factors affecting the abundance of Pondsmelt population in Lake Ashinoko (35°12'N, 139°E), we investigated the date of hatching, growth rate, and the age composition of pondsmelt. In addition, we estimated the seasonal and annual losses of pondsmelt due to predation by fish species present in the lake such as rainbow trout, brown trout, and largemouth bass. The results are summarized as follows:
(1) It was revealed from the estimation of the date of hatching and the growth rate of pondsmelts collected in the lake that the fish originating from released eggs were more frequent than those from spawnings.
(2) The 1+ age fish were dominant among pondsmelt caught by gill nets. This suggests that recent declines in the gill net catch may be chiefly caused by poor survival of the 1+ age fish.
(3) The estimated loss of the pondsmelt due to the predation by other fish exceeds that due to the fishing. Likewise the percentage of pondsmelt in the diet composition of largemouth bass remarkably increased in recent years; this suggests an increase in predation pressure by the largemouth bass.
Overall, these results indicate that predation is a crucial factor determining the abundance of pondsmelt in the lake.
View full abstract
-
Akihiro SUGITA, Hiroo YAMADA
1995 Volume 43 Issue 1 Pages
11-18
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The behavioral and morphological changes with growth in reared larvae and juveniles of the four-spine sculpin,
Cottus kazika were observed. Specimens used for breeding were wild mature fish collected from Kuzuryu River in Fukui Prefecture. Natural spawnings occured 13 times during the period from February 2 to April 2. The eggs were light yellow in color and their diameters were 1.70 to 1.81mm. The eggs were adhesive and clung to each other forming an egg-cluster.
The newly hatched larvae had large yolk sacs and from one to several oil globules. At birth, total length of the larvae was 6.2mm; total length increased to 22.2mm after 80 days. The larvae started to swim up to the surface and ate rotifers 8 days after hatching (7.1mm in total length) . Larvae at 41 days (13.1mm in total length) tended to swim at the bottom of the tank. At 50 days (16.3mm in total length), they lingered at the bottom and started to prey on each other. The larvae transformed into juveniles 74 days after hatching (21mm in total length) .
The appearance of melanophores and the formation of spines were compared with wild specimens.
View full abstract
-
Shotaro OHYA, Toshikazu SHIMIZU, Yoshiaki HORIKAWA, Shin-ichi YAMAMOTO
1995 Volume 43 Issue 1 Pages
19-22
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
Cultured Ayu,
Plecoglossus altivelis, with initial body weights between 20-25g, grew to about 40g in a period of a month around June. In that period, the best growth performance was observed in fish reared under water velocities of 20-30 cm/s, followed by 30-40 cm/s, 3-5 cm/s and 40-50 cm/s. In July, growth performances were directly proportional to water velocity. At the end of August, when the fish begin gonadal development, significant growth was observed velocities at velocities above 20 cm/s, Where as fish reared at 3-5 cm/s maintained positive growth. These findings indicate that rearing water velocity, accelerates growth of immature Ayu fish and on the contrary, inhabits the growth of Ayu in the vitellogenic stage.
View full abstract
-
Shotaro OHYA, Toshikazu SHIMIZU, Yoshiaki HORIKAWA, Shin-ichi YAMAMOTO
1995 Volume 43 Issue 1 Pages
23-26
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
We studied the effect of rearing water velocity on the mode of ovulation of cultured Ayu,
Plecoglossus altivelis. Ovulation was asynchremous (scattered ovulation mode) among fish reared at a velocity of 50-60 cm/s for at least 2.5 months before ovulation. In contrast, ovulation was concentrated over a short period (concentrated ovulation mode) when the fish were reared at a velocity of 3-5 cm/s for at least 1.5 months before ovulation when reared at 20-30 and 30-40 cm/s, and when reared at 50-60 cm/s for less than 2.5 months before ovulation. These results indicate that ovulation modes of cultured Ayu are regulated by water velocity. The concentrated ovulation mode is reasonable and progressive to conduce somatic growth and seedling production of Ayu.
View full abstract
-
Hitoshi KITO, Masahiko KUNIMOTO
1995 Volume 43 Issue 1 Pages
27-31
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The conchocelis of
Porphyra yezoensis f.
narawaensis has been obtained in axenic culture by disrupting and washing in SDS solution by using ultrasonication and subsequent spreading on solid ES medium. Isolated conchocelis confirmed its purity with Provasoli's STP
ss, ST3
ss, sabouraud's dextrose agar, and DAPI staining.
This result promise the easy maintenance of stock culture and the elucidation of physiological interesting concerning
Porphyra conchocelis.
View full abstract
-
Shigehisa YAMASAKI, Fujio UCHIYAMA, Hachiro HIRATA
1995 Volume 43 Issue 1 Pages
33-41
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The efficiency of bicarbonate addition on the growth of
Nannochloropsis sp. was investigated by measurement of cell volume and cell density increment after addition of sodium hydrogencarbonate. In measurement of cell volume increment, it increased rapidly by the addition of the sodium hydrogencarbonate, however, little or no increase of the cell volume was obtained in the control treatment. In the latter case, dissolved inorganic carbon (DIC) concentrations during the light photoperiod were determined to be lower than 15 ppm (as CO
2) on average. In measurement of cell density increment, transparencies of
Nannochloropsis sp. culture water were 60.7, 51.7, 46.8, and 47.2 % under DIC concentrations of 15, 20, 55, and 110 ppm, respectively, at 08: 00 on the 3rd day after initiation of culture. Masses of
Nannochloropsis sp. cells attached on the bottom and side of culture vessels at DIC concentrations of 55 and 110 ppm in the late light period of the 3rd day. It was suggested that an appropriate concentration for cell density increment was existed between 20 and 55 ppm.
View full abstract
-
Shigehisa YAMASAKI
1995 Volume 43 Issue 1 Pages
43-50
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The appropriate depth of the culture medium for mass culture of
Nannochloropsis sp. was estimated on the base of the photosynthetic rate. The relationship between photosynthetic rate and light intensity was represented by the following equation;
P=PmI/Ime (1-I/Im)
Where Pm is the maximum oxygen production rate, Im is the light intensity at Pm, and I is the light intensity. Pm and Im increased exponentially as temperature increased up to 25.6°C and decreased exponentially with further increases in temperature. The depths where average oxygen production rate from the surface of the culture became maximum were calculated to be 75-7cm within the range of chlorophyll content from 101 to 1, 767μg/l (2×10
6-30×10
6 cells/ml) under meteorological conditions prevailing in Kagoshima City, Japan, between April and October, 1988-1991, in which monthly average temperatures were 16.8-28.2 and solar radiations were 771-1, 000 μmol/m
2/sec. On the other hand, the depths of the compensation points were calculated to be 249-29 cm. Shallower values were obtained in June, rainy season, for both depths.
View full abstract
-
Katsuhiko HARADA, Taiko MIYASAKI, Yukiyoshi TAMURA
1995 Volume 43 Issue 1 Pages
51-55
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The attraction potential of sugars and related compounds were statistically estimated on thebasis of an exploratory and feeding behavior of yellowtail,
Seriola quinqueradiata. Among six monosaccharides, three disaccharides, six sugar alcohols, six glycosides, and two artificial sweeteners tested, the following compounds were found active; glucose, fructose, galactose, xylose, and rhamnose (monosaccharides), maltose and lactose (disaccharides), sorbitol and mannitol (sugar alcohols), glycyrrhizin, stevioside, rebaudioside, and phyllodulcin (glycosides), and saccharin and aspartame (artificial sweeteners) . Galactose, maltose, and glycyrrhizin were highly attractive, particularly glycyrrhizin. The attraction capability of glycyrrhizin and maltose increased as concentration increased.
View full abstract
-
Shusaku TAKAGI, Masahiko TAKEDA, Hidetsuyo HOSOKAWA, Sadao SHIMENO, Ma ...
1995 Volume 43 Issue 1 Pages
57-65
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The practical inclusion levels of deflated soybean meal (SBM) as a substitute for fish meal in mash for oregon moist pellet (OMP), mixed same weight with mash and raw sardine mince, was evaluated with yearling yellowtail,
Seriola quinqueradiata fed on test mashes containing SBM 0-30% for 162 days (expt. I) and 139 days (expt. II) .
In expt. I, the fish fed test mash containing SBM 10% was similar growth performance to the fish fed control mash free from SBM. In expt. II, best performance was found in the fish fed on mash containing SBM 20%, and same performance was found in the fish fed on mash containing 10% and 30% SBM.
There were no marked differences in proximate compositions of carcass, muscle and liver, and hematological characteristics among the groups.
These results indicate that commercial SBM proved to be a satisfactory alternative protein source of mash for OMP for yearling yellowtail, and practical inclusion levels in the mash should be 20-30%, replacing up to 25-38% of fish meal in mash.
View full abstract
-
Shusaku TAKAGI, Masahiko TAKEDA, Hidetsuyo HOSOKAWA, Sadao SHIMENO, Ma ...
1995 Volume 43 Issue 1 Pages
67-74
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The practical inclusion levels of corn gluten meal (CGM) as a substitute for fish meal in mash for Oregon moist pellet (OMP), mixed same weight with mash and raw sardine mince, was evaluated with yearling yellowtail,
Seriola quinqueradiata fed on test mashes containing CGM 0-30% supplemented with lysine and arginine for 134 days.
The growth performance increased in the fish fed on mash containing up to CGM 20%. But the performance decreased slightly in the fish fed on mash containing CGM 30% compared with the fish fed on control mash free from CGM.
Furthermore, hematological characteristics of the fish fed on test mashes reduced inversely related to CGM inclusion levels in mash, and the fish fed mash containing CGM 30% significantly decreased in hematocrit and hemoglobin levels compared with the fish fed control mash free from CGM.
There were no remaked differences in proximate compositions of carcass, muscle and liver among the groups.
These results indicate that commercial CGM proved to be a satisfactory alternative protein source of mash for OMP for yearling yellowtail, and practical inclusion levels in the mash should be 20%, replacing up to 25% of fish meal in mash.
View full abstract
-
Masashi NAKAJIMA, Toshio TAKEUCHI, Takeshi WATANABE, Sachio SEKIYA, Ma ...
1995 Volume 43 Issue 1 Pages
75-81
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
This experiment was conducted to clarify the adequate and excess amounts of n-3 highly unsaturated fatty acids (HUFA) in the diet for juvenile striped jack,
Pseudocaranx dentex. Experimental diets were formulated to contain 65% white or brown fish meal as protein source. Dietary lipid contents and n-3HUFA levels were adjusted to about 15% and 1.5-6.1%, respectively, using triglycerides (EPA 28 oil), a n-3HUFA mixture (Ester 85), beef tallow and palm olein. After a 10-week feeding experiments, best weight gain and feed efficiency along with the lowest hepatosomatic index (HSI) were observed in fish fed diets containing 2.3-3.4% n-3HUFA. Further elevation of dietary n-3HUFA content resulted in reduced growth and increased HSI. In the liver, moisture contents decreased and crude lipid contents increased with increase of dietary n-3HUFA level.
It is suggested that adequate levels of n-3HUFA in the diet and in the dietary lipid for juvenile striped jack are 2.3-3.4% and 15-25%, respectively, whereas excess amounts are more than 4.8% and 30%, respectively, at the 15% dietary lipid level.
View full abstract
-
Takafumi SHIKATA, Shunsuke IWANAGA, Sadao SHIMENO
1995 Volume 43 Issue 1 Pages
83-88
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
In order to investigate the effect of feeding frequency on the hepatopancreatic enzyme activities and the serum and body compositions, carp,
Cyprinus carpio were fed on a commercial diet once or 3 times a day for 30 days in the experiment 1 and on a glucose-based diet once or 4 times a day for 40 days in the experiment 2. The growth, protein retention, and hepatopancreatic fat content were lower in the fish fed once a day than in those fed several times a day in both experiments. The activities of lipogenic enzymes such as glucose-6-phosphate dehydrogenase and NADP-malate dehydrogenase were not affected by feeding frequency. In both experiments, the activities of gluconeogenic and amino acid-degrading enzymes such as glucose-6-phosphatase and aspartate aminotransferase were somewhat high in the fish fed once a day. These results suggest that the extremely low feeding frequency slightly accelerates amino acid degradation and gluconeogenesis in the hepatopancreas of carp, resulting in a low protein retention.
View full abstract
-
Gabriela del VALLE, Nobuhiko TANIGUCHI, Akio TSUJIMURA
1995 Volume 43 Issue 1 Pages
89-95
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The physiological effect of a shallow water stressor was tested on normal diploids, meiotic diploids, heterozygous and homozygous clones of the ayu,
Plecoglossus altivelis, in order to reveal potential physiological differences between the genetically manipulated groups. We measured the stressor effects on the hematocrit, leucocrit, hemoglobin, plasma glucose and mean corpuscular hemoglobin concentration and used replicas of the abovementioned fish groups as non-stressed controls. We found non-significant differences between the normal diploids and the genetically manipulated groups in 73% and 60% of the comparisons within non-stressed and stressed groups, respectively. Overall, a significant stress response was detected in 65% of the cases and was mainly characterized by alterations of the hematocrit, hemoglobin and plasma glucose levels. The expected reduction of the variation in the measured traits of the clones, in comparison to the normal diploids, was most prominent in the heteroclones.
View full abstract
-
Shingo SEKI, Motohiro TAKAGI, Nobuhiko TANIGUCHI
1995 Volume 43 Issue 1 Pages
97-102
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The genetic variability of the landlocked population of Ayu,
Plecoglossus altivelis in the Nomura dam was estimated using DNA fingerprinting and allozyme markers. Based on the allele frequencies of the
GPI-1 100 and
MPI 100 markers, it is suggested that the Nomura's population originated from the amphidromous form. Using 22 allozyme markers, the proportion of polymorphic loci and the average heterozygosity (Ho) were estimated as 0.182 and 0.061, respectively, suggesting that the genetic variability in the Nomura's population has been maintained at a level similar to the native amphidromous populations. On the other hand, the genetic similarity (as Band Sharing Index, BSI) obtained by DNA fingerprinting was 0.586 with YNZ22 probe, and 0.472 with 33.15 probe. These values were higher than those of the native amphidromous populations, suggesting that the effective population size (
Ne) of the Nomura's population is decreasing.
View full abstract
-
Sadaharu MAKINOUCHI, Ketut SUGAMA, Toni RUCHIMAT, TRIDJOKO, Tatam SUT ...
1995 Volume 43 Issue 1 Pages
103-108
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The effects of eyestalk ablatin on maturation, spawning, hatching, molting, and growth of the precocious pond-reared broodstocks ( (1) 4 month-old, (2) 5 month-old, (3) 1 year-old) and (4) wild spawner
P. monodon were investigated for cost reduction and facilitate the broodstock operation.
In group (1), there was significant difference (p<0.05) in the progress of ovarian maturation between ablated (GSI 0.59±0.22) and unablated females (GSI 0.33±0.12) after 35 days culture period. In group (2), it was observed that the minimum size at first ovarian maturation was 36g (BW) in ablated and 44g in unablated females. The minimum age or size at first spawning of female was observed in an ablated individual 5-month-old; weighting 38g. This individual fully matured and spawned two times 30 and 33 days after ablation (300, 000 total eggs/prawn) . The results suggested that it is possible to use precocious pond broodstock as a spawner.
On the other hand, in group (3), 50 % of unablated females matured and spawned 1-3 times between 4-16 days after the onset of the experiment (534, 000 total eggs/prawn) . In group (4), 43% of unablated females fully matured and spawned 1-3 times between 5-10 days after the onset of the experiment. They produced 2.2 million eggs and 1.2 million nauplii; mean hatching rate 63.1±13%. In contrast, 86% of the ablated females spawned at a rate of 4-7 times/spawner/month, but the hatching rate was only 19.4 ±17 %. From these results, it can be conclused that ablation increase maturation and spawning rates, however, unablated females show more higher fecundity, hatching, and survival rates. Furthermore, unablated females showed 2-10 times faster growth rate and shorter molt-cycle than that of ablated females.
View full abstract
-
Sadaharu MAKINOUCHI
1995 Volume 43 Issue 1 Pages
109-118
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
In order to investigate the effects of male situations on maturation, spawning, mating and hatchery cost of
P. monodon, six groups ( (1) first male, (2) second use male, (3) third use male, (4) ablated male, (5) pond male, (6) without male) were evaluated for a 31-day culture period, and replicated 8-63 times from 1987 to 1990.
The average spawning rate and fecundity in six groups showed no significantly difference (p>0.05), ranging from 63-80 % and 1, 150, 000-1, 337, 000 eggs per spawner/month, respectively. The mating and hatching rates varied as follows; 83.1% (41.4%) in first male, 72.3% (38.2%) in second use male, 70.8% (40.9%) in ablated male, 64.8% (31.9%) in third use male and 21% (24.6%) in pond male, respectively. However, there was no significant difference among group (1) - (4) except pond male (P>0.05) . Hatchery cost for 1 million nauplii in five groups was little difference, ranging from M$27-37. It can be conclused that second-or third-use male could be utilized more for reduced cost and to facilitate hatchery management.
Full ovarian maturation and spawning was attained 3-4 days after abration with a first peak at 5-6 days, and that a second peak occurred between 18-20 days. Spawning frequency was 25.5% at first, 28.3% at second, 26.1% at third, 13.9% at fourth, 5.6% at fifth and 0.4% at sixth spawning. Fully matured females spawned between 19: 00 and 07: 00 with 92% of occurring from 21: 00 to 04: 00. Release of eggs took 5 minutes, and the terms of spawning was characterized as 64.2% spawned in the same day and 34.4% within 1 day after stocking in the spawning tank.
In terms of the molt-cycle rhythm, there were also two peaks, first peak occurring between 10-12 days and second peak was between 26-30 days after ablation. It was observed that spawning increased 4-5 days after molting and decreased 4-5 days before molting. There was no relationship between female size, which ranged from 70-300g (BW), and molt-cycle duration. The molt-cycle duration of ablated females was between 13 and 25 days. Likewise, there was no correlation between female size and total number of eggs or nauplii for 1 month culture period.
View full abstract
-
Yoshiaki TANAKA, Shusaku KADOWAKI
1995 Volume 43 Issue 1 Pages
119-124
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
It is well known that there is a close relationship between pond water color during the culture period and final yield in prawn culture. Water coloration in the pond is divided broadly into brown color (brown wter) and green color (green water) . The purpose of this paper is to present the environmental characteristics of brown and green waters. The results obtained were as follows:
1) There was a difference in optical properties (transparency and extinction coefficient) between the brown and green waters.
2) Neglecting the effect of zooplankton respiration, bacterial respiration and phytoplankton respiration account for the total oxygen consumption in the pond water. An experiment was designed to distinguish bacterial respiration from phytoplankton respiration. Phytoplankton respiratory rate was responsible for 92% and 46% of the total respiration in the brown and green waters, respectively.
3) Regarding the relationship between dissolved inorganic nitrogen (DIN) and inorganic phosphate (IP) concentrations in pond water, brown and green water were clearly classified into two groups of DIN/IP ratio respectively over and under 3.5. It is suggested that phytoplankton composition and consequently water coloration in the pond depend on the DIN/IP ratio of sea water.
View full abstract
-
Yasuhiko TOSHIMA, Katsutoshi ARA, Koichi YOSHIMURA
1995 Volume 43 Issue 1 Pages
125-128
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The bioconcentration of
n-dodecylbenzene sulfonate (C
12LAS) was investigated in goldfish,
Carassius auratus, using a long term continuous flow system. The bioconcentration factor (BCF) of fish exposed for 26 days to a test solution with 1.0 mg C
12LAS/
l was low. The BCF were 1 or less in the liver and kidney, approx. 30 in the gills, and about 20 in the whole fish body. However, the BCF was about 1000 in the gall bladder. In addition, peaks of possible metabolites as well as C
12LAS itself were found on the HPLC chromatogram of the bile. These facts suggested that C
12LAS was positively metabolised in the fish. When the concentration of the test solution was 0.5 mg C
12LAS/
l, the tendency of bioconcentration in the gall bladder and whole body was similar to that under exposure to the concentration of 1.0 mg/
l.
View full abstract
-
Minoru TAKABA, Tomohisa KATOU
1995 Volume 43 Issue 1 Pages
129-135
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
Red sea bream seeds from two different origins were released in Aug. 1992 into Okiura Fishing Port and fed by acousitc conditioning and ordinary artificial feeding until Dec. 1992. During this period, we surveyed the growth, dispersion, of as well as triglycerides (TG) and RNA/DNA ratio of the fish. A total of 2699 red sea bream were recaptured in 125 samplings with basket net. The numbers of individuals caught decreased steadily with time during periods (40 to 110 days after release) and 2 (110 to 135 days), but not in Period 0 (0 to 40 days) . Survival rates (S) were 98.3% (P1) and 93.3% (P2) . The dispersion rates (1 minus S) were 1.7% (P1) and 6.7% (P2) . Dispersion began when the temperature of water fell, red sea bream seeds were no longer recaptured at or below 15°C. The amount of TG in the liver decreased steadily from 3.3-4.6%at the time of release until 31-38 days after release. The rate of decrease, however, was smaller than when the seeds were directly released outside the fishing port. RNA/DNA ratio, which was 3.5 at the time of release and fell to 2.6-2.8 at 10 days after release, but recovered after the 17th day. Overall, it appears that release artificial feeding with in the port have no negative effects on redsea bream and that the seeds adapt well to the release site. Furthermore, the seeds successfully disperse to the outer waters. These results suggest that fishing port waters are an appropriate place for release of artificially propagated seeds.
View full abstract
-
Hironobu KOMAKI, Koji TOYOTA, Koichi MASAOKA, Naoya OHTSUKI
1995 Volume 43 Issue 1 Pages
137-143
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The acceleration of spawning of red sea bream,
Pagrus major was attempted by subjecting the fish of 20°C to either a constant water temperature or to a temperature 3°C higher (+3°C group) than that of natural sea water. Fish maintained under natural sea water served as controls. Spawnings under 20°C began 1-1.5 months earlier than in the control. The beginning of spawning in the +3°C group occurred 0.5 month earlier than that of control. The percentages of buoyant eggs and viable hatching of eggs spawned at 20°C were higher than those of the control.
The egg diameters of the +3°C group and of the control were inversely correlated with the water temperature. Since the variation in egg diameter at 20°C was small, it is suggested that these parameter can also be controlled by water temperature.
These results suggest that the manipulation of water temperature may be an effective method for the acceleration of spawning and the improvement of the yield of viable hatching.
View full abstract
-
Osamu MURATA, Shigeru MIYASHITA, Toshiro NASU, Hidemi KUMAI
1995 Volume 43 Issue 1 Pages
145-151
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
This study compared the growth, survival, external morphology, and resistance to environmental stress of the hybrids of red sea bream,
Pagrus major (_??_) and black sea bream,
Acanthopagrus schlegeli (_??_) with the pure breeds. The fertilization rate among buoyant eggs obtained by artificial insemination was the highest in black sea bream, followed by red sea bream and the hybrid. The hatching rate was highest in red sea bream, followed by black sea bream and the hybrid. The survival rate 30 days after hatching was the highest in red sea bream, followed by the hybrid and black sea bream. However, the survival rate 71-140 days after hatching was much higher in the hybrid and black sea bream than in red sea bream. Growth until about 8 months after hatching was faster in the hybrid, followed by red sea bream and black sea bream. However, red sea bream gradually outperformed the hybrid from 1 year. After 3 years, the size of the hybrid was about twice that of black sea bream, and half that of red sea bream. The resistance to variation in water temperature or decreases in specific gravity and dissolved oxygen of the hybrid were lower than those of black sea bream but considerably higher than those of red sea bream. The hybrids were closer to black sea bream in the external morphology and body color, suggesting more marked paternal inheritance.
View full abstract
-
Sung Hee JUNG, Hiroshi KAWATSU
1995 Volume 43 Issue 1 Pages
153-156
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
The hemostatic disorder in the common carp induced by exposure to the herbicide molinate and the preventive effect of menadione dimethylpyrimidinol bisulfite (MPB) were examined by means of clotting time and chromogenic substrate assay using S-2337. Fish were arranged in three groups of 7 animals each. The fish in the first group were exposed to molinate alone at 0.32 ppm, those in the second group to 0.32 ppm of molinate and 32.4 ppb of MPB, and those in the third group served as the control. Measurements of activated partial thromboplastin time (APTT), prothrombin time (PT), Russell's viper venom time (RVVT) and chromogenic substrate assay (CSA) were performed at the start, and after 7 and 12 days of exposure. Prolongation of APTT, PT, and RVVT, and a decrease in absorbance in the CSA were observed after 7 days of exposure to molinate. Thereafter, the prolongation of PT became more pronounced than that of APTT and RVVT, indicating that dysfunction of the extrinsic pathway was more severe than that of intrinsic and common pathways. MPB was highly effective in preventing the prolongation of clotting time and the decrease in absorbance in the CSA.
View full abstract
-
Termpong WAYUSUWANWIT, Hiroshi KAWATSU
1995 Volume 43 Issue 1 Pages
157-161
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
An investigation on the acute toxicity and hemolytic activity of a homologous series of anionic surfactant, sodium alkyl (C
5-C
12) sulfonate, was carried out using common carp
Cyprinus carpio. The 96-h LC
50 ranged from 0.25mM (C
12) to 129mM (C
5), and 50 % hemolysis concentration ranged from 0.37mM (C
12) to 730mM (C
5) . The acute toxicity and hemolytic activity increased with increasing length of the alkyl chain. In addition, a close relation between LC
50 and 50% hemolysis concentration was observed. This finding suggests that cytotoxic effects of these surfactants are the cause of death of the experimental fish.
View full abstract
-
1995 Volume 43 Issue 1 Pages
163-176
Published: March 20, 1995
Released on J-STAGE: March 09, 2010
JOURNAL
FREE ACCESS
