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Vol.01-10
No.11-20
No.21-30 No.31-40
No.41-50
No.31 No.32
No.33 No.34
No.35 No.36
No.37 No.38
No.39 No.40
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Sci. Rep. Hokkaido Fish Hatchery
(40), 1986
- 40-1
Changes in composition of the muscles during the spawning
migration of chum salmon. Shimizu, I., and Nomura, T. pp.
1-9. (In Japanese with English summary)
 (414KB)
Abstract
The contents of lipid, moisture,
and protein in the muscle of chum salmon during the spawning
migration were examined. The amount of total lipid was lower in
adults from the Chitose River than in these from the coastal
water, while the moisture content was higher in mature salmon
than in maturing salmon during the seawater migration. In chum
salmon during the spawning migration, the total lipid decreased
but the moisture increased. In addition, the triglyceride
contents decreased, but phospholipid was maintained at a
constant levels.
- 40-2
Two species of Chloromyxum (Myxozoa: Myxosporea) in chum
salmon, Oncorhynchus keta (Walbaum): taxonomy and life
cycle. Urawa, S., and Hiroi, O. pp. 11-20. (In Japanese with
English summary)(595KB)
Abstract
Chloromyxum wardi
Kudo, 1920 and C. salvelini Fujita, 1923 from adult chum
salmon in the Chitose River were described, and their life
cycles were speculated. Morphological comparisons with other
species of Chloromyxum revealed that C. chitosense
Fujita, 1923 is synonymous with C. wardi. Chum salmon fry
became infected with both species during their freshwater life,
but spore formation might not occur for 2.5 to 4.5 years after
the seaward migration. Young trophozoites of the parasites were
present in the gallbladder of maturing chum salmon that migrated
into the coastal waters near their natal river. By the time of
spawning, the spore formation had completed, and mature spores
were expelled through the host's intestine into fresh water.
Prevalences of spores of C. wardi and C. salvelini
in spawning chum salmon were 59.6% and 23.7%, respectively, and
decreased over the course of the spawning season.
- 40-3
Zooplankton study at the coast of Ishikari Bay I. The
distribution and body size of two species, Tortanus
discaudatus and Centropages abdominalis (Copepoda:
Calanoida). Seki, J., Shimizu, I., and Mayama, H. pp. 21-30.
(In Japanese with English summary)(464KB)
Abstract
Vertical distribution and body
size of two copepod species, Tortanus discaudatus and
Centropages abdominalis, were investigated in the Ishikari
Bay from March to June, 1981. The abundance of these species
showed a peak in the early May. Males of both species were more
abundant than females in all layers in April and in the upper
layer (0-1 m in depth) in May.
- 40-4
Ecological study on early life of the chum salmon,
Oncorhynchus keta (Walbaum). Kaeriyama, M. pp. 31-92.
(In Japanese with English summary)(9,213KB)
Abstract
Life history pattern of chum
salmon during their early life period was investigated in
Hokkaido and Sanriku coast of Tohoku region based on the
morphology, development, growth, distribution, migration, and
feeding ecology. Developmental stages of chum salmon in the
early life period were morphologically and ecologically
classified into alevin (20-38 mm in fork length (FL)), fry
(38-50 mm in FL), pre-fingerling (50-80 mm in FL), and
post-fingerling (80-120 mm in FL), with the period from fry to
fingerling as the juvenile stage. The early life history pattern
of chum salmon was classified into "river type", "foraging
migration type", and "escaping migration type".
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Sci. Rep. Hokkaido Fish Hatchery
(39), 1985
- 39-1
Experimental release of masu salmon, Oncorhynchus masou,
smolts into the Shiribetsu River. Adult returns of marked fish
released in the spring of 1981. Mayama, H., Ohkuma, K.,
Nomura, T., and Matsumura, K. pp. 1-16. (In Japanese with
English summary)(2,288KB)
Abstract
Preliminary studies on the release
of masu salmon smolts were carried out in the spring of 1981.
About 70,000 hatchery-produced smolts were marked by
fin-clipping and released into the Shiribetsu River, Hokkaido. A
total of 481 marked maturing fish were recaptured in the coastal
waters near the river mouth from February to June in the next
year. The size of marked fish recovered in the coast averaged
53.5 cm in fork length and 2.43 kg in body weight. In addition,
361 marked masu spawners were recaptured in the river. The
estimated return rate was 0.7 % in the natal river, 5.8 % in the
coastal waters within 50 km from the river mouth. Only one
marked fish of 4 years old returned the next year, spending two
winters in fresh water. Thus it became clear that masu salmon
spend only one year in the ocean.
- 39-2
On the studies of scale pattern and growth of masu salmon (Oncorhynchus
masou) 2. Growth and scale pattern of hatchery reared masu
salmon returned in 1982. Ohkuma, K., and Mayama, H. pp.
17-25. (In Japanese with English summary)(428KB)
Abstract
The scale pattern of adult masu salmon
in the Mena River of the Shiribetsu River System was examined
for the growth estimation. Their fork length at the beginning of
seaward migration was estimated by Belding's back-calculation
formula. There was no significant correlation between the actual
and estimated fork lengths, suggesting that large smolts did not
always grow larger by their return. The proportion of fish with
resting zone in the scales was lower in the large group than in
the small one. 73% of masu adults had an intermediate band in
the scale. Average number of circuli and width of this band were
5.4 and 0.158 mm, respectively. An allometric relationship
between scale radius and fork length was not sufficiently
satisfied in the period just after the beginning of scale
formation.
- 39-3
Food and feeding habit of juvenile salmon (genus Oncorhynchus)
in coastal waters of Ishikari Bay, Hokkaido-II. Vertical
distribution of food organisms of the coastal waters in spring,
1980-1981. Seki, J., Mayama, H., and Shimizu, I. pp. 27-90.
(In Japanese with English summary)(2,002KB)
Abstract
Vertical distribution of zooplankton
was investigated in the Ishikari Bay from late March to June in
1980 and 1981. The standing crop of zooplankton decreased after
late May. The dominant species were Pseudocalanus minutas
and Calanus plumchurus in March and April, medusa
in early March, and Evadne nordmanni after late May. The
abundance of zooplankton exceeded in the layer between 5 to 20
m. Low salinity in the upper layer may prevent the distribution
of zooplankton.
- 39-4
Ecological studies on the chum salmon, Oncorhynchus keta,
fry and its surroundings in the coastal waters of the Nemuro
Strait in spring, 1984. Kasahara, K. pp. 91-111. (In
Japanese with English summary)(908KB)
Abstract
Early marine life of chum salmon in
the Nemuro Strait was investigated in the spring of 1984. Chum
salmon fry inhibited in the shore area between May and mid June.
Juveniles were distributed in the coastal water until early July
when the water temperature became 12-13°C.
- 39-5
The effect of temperature on the toxicity of the MEP (sumithion)
and the heat acclimation on the rainbow trout. Hashimoto, S.
pp. 113-123. (In Japanese)(1,202KB)
Abstract
Toxicity of MEP (sumithion) for
rainbow trout was studied. The TLM within 24 hours increased
with a increase of water temperature, being 12.8-42.4 ppm at
7.7-20.6°C. The toxicity was also influenced by the condition of
fish.
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Sci. Rep. Hokkaido Fish Hatchery
(38), 1984
- 38-1
Food and feeding habit of juvenile salmon (genus Oncorhynchus)
in coastal waters of Ishikari Bay, Hokkaido-I. Horizontal
distribution of food organisms of the coastal waters in spring,
1977-1981. Seki, J., Mayama, H., and Shimizu, I. pp. 1-23.
(In Japanese with English summary)(1,142KB)
Abstract
Horizontal distribution and
temporal change of zooplankton were surveyed in the Ishikari Bay
from March to July in 1977-1981. Abundance of zooplankton showed
a peak in late March or April. The dominant species in the
zooplankton fauna changed from cold-water copepods (mainly
Pseudocalanus minutus) to warm-water cladocerans in May. The
zooplankton fauna was different between the coastal and offshore
areas.
- 38-2
On the studies of scale pattern and growth of masu salmon (Oncorhynchus
masou) 1. Age and scale pattern in fresh water life.
Ohkuma, K., and Mayama, H. pp. 25-31. (In Japanese with English
summary)(435KB)
Abstract
The scale pattern was examined for
masu salmon parr, smolt and adults in the Mena River, a branch
of the Shiribetsu River, Hokkaido. Number of circuli and scale
radius (nucleus to the edge of 1st annulus) of 1+ year resident
parr captured in July were 6-12 (mean 8.8) and 0.14-0.36 mm
(mean 0.25 mm), respectively. Some of these 1+ fish might
migrate to sea in the following spring as 2+ smolt based on an
evaluation of their gonad development. Age determination from
668 adult masu salmon returned to the Mena River in 1982 and
1983 revealed that age 2.1 fish represented 6.7% in1982 and 9.4%
in 1983, while others were age 1.1 fish.
- 38-3
A study on the physiology of masu salmon (Oncorhynchus masou)
-I. Change in crude fat content. Nomura, T. pp. 33-41. (In
Japanese with English summary)(428KB)
Abstract
Changes in the crude fat content
in the muscle of masu salmon in fresh water and seawater were
determined using the Soxlet method. The fish samples were
collected from rivers and coastal waters of Hokkaido and
Niigata. The crude fat content in the muscle tissue of juveniles
in fresh water increased from spring to summer, and rapidly
decreased in autumn. In winter, it declined to approximately 1%
of muscle wet weight. In the following spring, it increased in
parr but declined in smolts. The crude fat content in the muscle
tissue of fish collected from the coastal sea was significantly
higher than that of fish in fresh water.
- 38-4
On the distribution of the related three species of genus
Bryocamptus (Copepoda, Harpacticoida), in Hokkaido and
Honshu, Japan. Ishida, T. pp. 43-49. (In Japanese with
English summary)(267KB)
Abstract
The geographical distribution and
morphology of freshwater copepods, Bryocamptus hiemalis,
B. nivalis, and B. calvus in Hokkaido and Honshu
were reported in this paper.
- 38-5
On the newly discovered three species of copepod Halicyclops
sp., Acanthocyclops venustoides bispinosus (Yeatman)
and Attheyella dentata (Poggenpol) of fresh waters of
Hokkaido, Japan. Ishida, T. pp. 51-56. (In Japanese with
English summary)(263KB)
Abstract
Halicyclops
sp., Acanthocyclops venustoides bispinosus, and
Attheyella dentata were identified on the basis of specimens
collected from freshwater areas in Hokkaido. The latter two
species are the first record from Hokkaido. The geographical
distribution in Hokkaido and morphology of these species were
noted.
- 38-6
Characteristics of water supplies in salmon hatcheries of
Hokkaido. Shimizu, I. pp. 57-77. (In Japanese with English
summary)(862KB)
Abstract
Water supplies of salmon
hatcheries were divided into spring water, groundwater,
infiltration water, and river water. In spring water, the
concentrations of chloride ion, silica and phosphate were higher
than in other waters. In ground water, not only water
temperature but the concentration of ammonium-N, nitrate-N and
total iron was higher, while pH value and sulfate ion were lower
level than in other waters. In infiltration water, the
concentration of magnesium ion was higher, but water temperature
and silica were lower than in other waters. In artesian well
waters, the level of ammonium-N, nitrate-N and total iron was
often high. Therefore, the water quality of these waters should
be analyzed before using for salmon eggs.
- 38-7
Southern extreme in the range of pink salmon, Oncorhynchus
gorbuscha, along the Pacific coast of Honshu, Japan.
Kaeriyama, M., and Hikita, T. pp. 79-82. (In Japanese with
English summary)(3,171KB)
Abstract
A pink salmon was caught in the
lower Oh River, Miyagi Prefecture, Japan, on August 26, 1983.
The specimen was a mature male measuring 457 mm in fork length.
The scale counts on the lateral line was 193. Number of circuli
on scale in first year of this fish was fewer than that of pink
salmon in Hokkaido. The Oh River is located about 120 km south
of the Akka River which was previously reported as the
southernmost distribution of pink salmon in Japan.
- 38-8
Further records on the small pink salmon (Oncorhynchus
gorbuscha) caught in Hokkaido, Japan. Hikita, T. pp.
83-88. (In Japanese with English summary)(306KB)
Abstract
Precocious male and small adult of
pink salmon were recorded from rivers along the Okhotsk Sea
coast of Hokkaido. Their morphological characters were described
in this paper.
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Sci. Rep. Hokkaido Fish Hatchery
(37), 1983
- 37-1
Studies on the chum salmon released in the Ishikari River
System-II. On the seaward migration and inshore distribution of
liberated fry in 1980 and 1981. Mayama, H., Seki, J., and
Shimizu, I. pp. 1-22. (In Japanese with English summary)(988KB)
Abstract
Downstream migration and inshore
distribution of chum salmon fry were examined in the Chitose
River, Ishikari River System from March to June in 1980 and
1981. Chum salmon fry released in early March migrated to the
coastal sea from late March to early May after staying in the
upper stream for 1-2 months, while most chum fry released in mid
April migrated to sea within 10 days after the release. Chum
salmon fry captured in the coastal area near the river mouth
during a period of offshore migration were clearly differed in
the body size between 1980 and 1981. It was considered that many
chum fry of 1980 releasing group could not stay in the river and
died soon after migrating to the coastal water, because they
decreased the swimming performance due to possible diseases.
- 37-2
Growth-rate and smolting-rate of anadromous "masu" salmon (Oncorhynchus
masou) juveniles under artificial conditions. Kubo, T.
pp. 23-39. (In Japanese with English summary)(926KB)
Abstract
Rearing experiments of anadromous
masu salmon juveniles were conducted at the Nanae Fish Culture
Experimental Station from 1952 to 1982. Usually, the separation
of the two modes in the frequency distribution of body length
begins in the late summer of the first year of life, and the
feature of bimodality becomes clear in the following spring. The
climax of the smoltification of masu salmon juveniles occurs
from late April to late May in southern Hokkaido. The fish
ranked in the upper mode of length frequency are mainly composed
of smolts and precocious male parr which matured previously
during the preceding autumn. The critical minimum size for
smoltification is approximately 11 cm in total length at the mid
smolt stage. The results of rearing experiment in an artificial
small stream suggest that the smolting rate of juvenile masu
salmon in natural stream may be considerably high, if the
environmental factors are favorable for their growth.
- 37-3
On the device for stamina measurement of salmon fry.
Kobayashi, T., and Ohkuma, K. pp. 41-44. (In Japanese)(768KB)
Abstract
Besides the fatness and seawater
tolerance of salmon fry, the swimming performance may be an
index of fish health and quality. A new apparatus was developed
for measuring stamina and swimming capacity of salmon fry to
evaluate their quality.
- 37-4
On the distributions of the related three species and a variety
of genus Attheyella (Copepoda, Harpacticoida), in
Hokkaido and Honshu, Japan. Ishida, T. pp. 45-51. (In
Japanese with English summary)(292KB)
Abstract
The geographical distribution of
Attheyella sp., A. nakaii, a variety of A.
nakaii, and A. coiffaiti was reported. In addition,
morphological variations among these species were noted.
- 37-5
Incidence of Aeromonas salmonicida among chum salmon,
Oncorhynchus keta, in Chitose River. Nomura, T., Kimura,
T., Shimizu, I., and Nara, T. pp. 53-61. (In Japanese with
English summary)(452KB)
Abstract
In 1980 and 1981, the incidence of
Aeromonas salmonicida, the causative agent of fish
furunculosis, was examined for adult chum salmon in the Chitose
River. The incidence of A. salmonicida was higher in
adults held in ponds than these in the river.
- 37-6
Incidence of Aeromonas salmonicida among anadromous
salmonids, 1980-1982. Nomura, T. pp. 63-65. (In Japanese)(127KB)
Abstract
From 1980 to 1982, the incidence
of Aeromonas salmonicida was examined for apparently
normal adults of chum, pink and masu salmon in Hokkaido and
Niigata. The incidence was from 0% to 100% in this study.
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Sci. Rep. Hokkaido Fish Hatchery
(36), 1982
- 36-1
Studies on the chum salmon released in the Ishikari River System-I. On the
seaward migration and inshore distributions of liberated fry in 1979. Mayama,
H., Kato, M., Seki, J., and Shimizu, I. pp. 1-17. (In Japanese with English
summary)(845KB)
Abstract
Seaward migration and coastal distribution of
europium-marked and non-marked chum salmon fry were examined in the Chitose
River, Ishikari River System, the adjacent coastal water in the spring of 1979.
Almost all marked fry released on April 2 migrated to the coastal sea within 10
days after the release. The chum fry obtained in the intertidal zone from March
to May were 3.0-4.5 cm in fork length (FL). In the coastal zone, the fry stayed
mainly in shallow waters near the mouth of the river in April (4.5 cm in average
FL), in deep waters in May (5.7 cm in average FL), and displaced from the
adjacent waters to the river in June (7.0 cm in average FL). Furthermore, marked
fry were collected frequently in early and middle June in the northern coastal
waters of Hokkaido. These results suggested that chum salmon fry migrated
north-ward along the shoreline with a large schooling, and that their offshore
migrations occurred when the fry attained to approximately 7 cm in the minimum
FL.
- 36-2
Research on culture of chum fingerlings for stocking-II. Consistency of diet,
feeding skill, frequence, time, and insufficient water flow. Hashimoto, S.
pp. 19-37. (In Japanese with English summary)(977KB)
Abstract
The author estimated effects of diet consistency,
feeding skill, frequency, time, and insufficient water flow on the health of
chum salmon fry. The results showed that feeding by hand was not good from the
view point of food efficiency, but it was improved by using an automatic feeding
machine.
- 36-3
Studies on the metabolic functions of young chum salmon, Oncorhynchus keta
(Walbaum)-III. Effect of deletion of vitamin C and K from and addition of water
to manufactured diet. Hashimoto, S. pp. 39-47. (In Japanese with English
summary)(496KB)
Abstract
A sufficient supply of water to artificial diets
seems to prevent physiological trouble of chum salmon fry. Chum salmon fry seem
to like essentially soft and watery diets. However, the soft and knead diets
with full moisture like cement-mixer food will pollute the rearing water,
encouraging occurrence of diseases. The hematocrit value did not change despite
deleting vitamin K.
- 36-4
Further notes on the freshwater harpacticoid copepods of Hokkaido, northern
Japan. Ishida, T. pp. 49-61. (In Japanese with English summary)(400KB)
Abstract
In addition to the prior report (35-4), 8 species
of freshwater harpacticoid copepods and male of Moraria sp. were
identified on the basis of specimens collected in fresh water in Hokkaido.
- 36-5
Vibriosis in chum salmon fry-I. The occurrence and symptoms. Nomura, T.,
Tomioka, K., and Shimizu, I. pp. 63-69. (In Japanese with English summary)(1,829KB)
Abstract
This communication described an outbreak of
vibriosis in chum salmon fry reared in a saltwater pond. The epizootic occurred
among 50,000 chum salmon fry (mean fork length, 3.2 cm; mean weight, 1.47 g).
The highest mortality was 2.1% per day. Internally numerous hemorrhages were
present on the liver of moribund fish. All culture plates inoculated with the
kidney and liver from the diseased fish showed pure or predominant growth of
gram negative curved rod. The bacterium was identified as Vibrio sp. This
is the first record of vibriosis of chum salmon fry in Hokkaido.
- 36-6
Required oxygen discharge into the fish transport tank for the adult chum
salmon. Hashimoto, S. pp. 71-78. (In Japanese)(164KB)
Abstract
The author estimated the optimum oxygen
concentration for adult chum salmon transported in a canvas tank (3.6 x 1.1x1.0
m). The oxygen release pressure per fish weight (100 kg) must be 4.0-5.9 L/min
for active fish, but 3.8 L/min for resting fish.
- 36-7
On the
benthic Cladocera and Copepoda of Lake Shikotsu, Hokkaido, northern Japan.
Ishida, T. pp. 75-78. (In Japanese)(148KB)
Abstract
The benthic crustacean fauna was examined in Lake
Shikotsu during the early winter of 1980 and late spring of 1981. Three
cladoceran, 9 cyclopoid, and 8 harpacticoid species were recorded. Vertical
distribution and seasonal change of harpacticoids were also noted in this paper.
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Sci. Rep. Hokkaido Fish Hatchery
(35), 1981
- 35-1
Studies on the metabolic
function of adult chum salmon, Oncorhynchus keta (Walbaum)-IV. Analysis
of adult chum salmon's behavior and activity measured by oxygen meter in the
stocking pond. Hashimoto, S. pp. 1-8. (In Japanese with English summary)(438KB)
Abstract
The author analyzed the behavior of adult chum
salmon, comparing with patterns of fluctuation of dissolved oxygen concentration
in the inlet and outlet of holding ponds. The fish showed a trend to migrate
upstream toward the inlet with a special moving behavior during the night when
the oxygen concentration increased. An increase of the oxygen concentration
level might be a trigger to increase the activity of adult salmon in holding
ponds.
- 35-2
On the coho
salmon transplanted from North America into the Ichani River. Umeda,
K., Matsumura, K., Okukawa, G., Sazawa, R., Honma, H., Arauchi, M.,
Kasahara, K., and Nara, K. pp. 9-23. (In Japanese with English
summary)(2,364KB)
Abstract
Two hundred thousand eyed eggs of coho
salmon were transplanted in Hokkaido from North America. Growth,
dispersal and smoltification of coho juveniles released into the
Ichani River in May and August were studied. Coho juveniles grew
rapidly during spring and summer, but did slowly during late fall
through winter. In the next spring, coho juveniles again grew
rapidly with a gradual increase of water temperature. A number of
juveniles recaptured in planted pools in the Ichani River decreased
gradually with an approach of winter season. They overwintered in
several spring streams where the water temperature was constantly
high, or in some pools where driftwood were fallen in. From April to
June, coho smolts began to move downstream. The seaward migration
became most frequently in early June, being earlier than that in the
domestic masu salmon.
- 35-3
Note on the aggressive
behaviour of juvenile chum salmon, Oncorhynchus keta (Walbaum).
Yamagishi, H., Matsushima, T.,
and Nakamura, M. pp. 25-31. (In Japanese with English summary)(2,734KB)
Abstract
Aggressive behavior, social hierarchy, and growth
of juvenile chum salmon were studied in freshwater and seawater aquariums.
Nipping, chasing, lateral display, wigwag display, fighting, and territory
defense were always observed. A dominance order of incomplete nip dominance type
was recognized all the time.
- 35-4
A preliminary account of
the freshwater harpacticoid copepods of Hokkaido, northern Japan. Ishida, T. pp.
33-56. (In Japanese with English summary)(877KB)
Abstract
Fifteen species (7 genera) of freshwater
harpacticoid copepods were identified on the basis of specimens collected from
seeping springs, small streams, ponds, and lakes in Hokkaido.
- 35-5
The fishes from eastern
waters and rivers of the Shiretoko Peninsula in Hokkaido, Japan. Hikita, T. pp.
57-88. (In Japanese with English summary)(13,570KB)
Abstract
Nemuro Strait is known as one of the most important
fishing grounds in Hokkaido. This paper is a report on fishes collected from
commercial catches by set net, gill net, and long line operations. One hundred
and thirty fish species (46 families including 98 genera) were recorded between
1952 and 1980.
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Sci. Rep. Hokkaido Fish Hatchery
(34), 1980
- 34-1
Studies on the life
history of the "masu" salmon (Oncorhynchus masou) in Hokkaido.
Kubo, T. pp. 1-95. (In Japanese with English summary)(7,237KB)
Abstract
Masu salmon varies from other
Pacific salmon species in being geographically restricted to the western region
of the North Pacific Ocean. Various developmental stages and phases of masu
salmon cause several problems in the study of their life history. Each stage is
characterized by the external appearance, somatic growth, behavior pattern, and
response of fish to various environmental factors. The stream life of masu
salmon juveniles is divided into the larval, parr and smolt periods. Also, the
ocean life of young salmon and the stream life of maturing adults are
respectively divided among many stages. A period from the phase differentiation
to smolt transformation is very important and critical in their life history.
Intensive studies on various physiological and ecological aspects of masu salmon
life history are presented in this paper.
- 34-2
Studies on the planting
of hatchery-cultured masu salmon fry into streams 8. Observations on dispersal
and residence of fry released in different manners. Ohkuma, K., Sasaki, S., and
Sato, Y. pp. 97-103. (In Japanese with English summary)(389KB)
Abstract
Dispersal and residence of masu salmon fry released by
different methods were observed in three tributaries of the Mena River:
Sannosukesawa, Tsubamenosawa, and Kusurinosawa. Four thousand fry released in a
point of upper reaches of Sannosukesawa resided as about same numbers as
released in four points, one thousand respectively, in previous observation.
However, these results show little difference between two manners, because
density of previously resided native fry diversified greatly between previous
and this observation. Upward dispersion of released fry occurred markedly in
three tributaries in this observation, perhaps due to weather and water flow
condition at releasing time. A priority phenomena was confirmed in the
observation of Tsubamenosawa.
- 34-3 Studies on the metabolic
function of adult chum salmon, Oncorhynchus keta (Walbaum)-III. Oxygen
consumption and metabolic excretion of adult chum salmon under crowded
conditions, and influences of diurnal and daily fluctuation of dissolved oxygen
concentration in water being supplied into the stocking pond upon the pond
capacity. Hashimoto, S., Abe, T., and Kato, H. pp. 105-113. (In Japanese with
English summary)(530KB)
Abstract
The author examined oxygen
consumption, carbon dioxide and ammonium excretion of adult chum salmon held in
a pond at high density. The oxygen consumption of maturing fish was maintained
at a high level even 1.5 hours after these fish selection by hands. The lowest
dissolved oxygen concentration was recorded between 4 a.m. and 7 a.m. The mean
NH4-N excreted from adult chum salmon was 0.13 mg/kg/min.
- 34-4
On the water-washing
time of chum salmon eggs soon after the artificial fertilization. Hiroi, O. pp.
115-120. (In Japanese with English summary)(419KB)
Abstract
Optimum water-washing time of fertilized eggs was
investigated in the Chitose Hatchery and Nijibetsu Hatchery. There was a
significant difference in occurrence of stillborn egg among the non-sperm eggs
between broods from mature fish soon after the catch in the Chitose (1.6%) and
those from held fish over 7 days after the catch in the Nijibetsu (4.5%). High
stillborn egg contents of the broods in the Nijibetsu resulted in not only the
increase in mortality of fertilized eggs but also the decrease in fry-liberation
rates, suggesting possible influences due to the artificial holding of fish up
to full maturation. Fertilized eggs treated by two-hour suspension of water
supply at 5 to 45 minutes after the fertilization died more or less, mainly in
early egg-developing stage, 0 to 200°C in daily cumulative water temperature
after the fertilization. From the result, it was shown that chum salmon eggs
soon after the artificial fertilization needed to wash over 30 minutes into
running waters with adequate current, for transporting them with suspension of
water supply.
- 34-5
On the mesh selectivity
of gillnet for kokanee. Ishida, T., Tanaka, M., and Ohkuma, K. pp. 121-123. (In
Japanese with English summary)(139KB)
Abstract
Mesh selectivity of gill nets for
lacustrine sockeye salmon "himemasu" was examined in Lake Shikotsu and Lake
Yunoko. Large salmon showed a tendency to be captured by a tangle with gill
nets.
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-
Sci. Rep. Hokkaido Fish Hatchery
(33), 1979
- 33-1
Studies on the planting of hatchery-cultured masu salmon fry into streams 7.
Effect of released time and priority on the residence of fry. Ishida, T.,
Sasaki, S., and Sato, Y. pp. 1-6. (In Japanese with English summary)(281KB)
Abstract
Optimum stocking time in a day and
effect of priority on residence were examined for masu salmon fry released in
the Mena River of the Shiribetsu River System. There was no difference in
dispersal migration among masu salmon fry released in morning and evening. Masu
salmon fry were stocked into the same place in the continuous two days. The fry
stocked in the first day grew faster than the fry stocked in the second day.
This result suggested that a prior resident masu salmon fry dominated over a
posterior resident fry in a habitat.
- 33-2
On the
coho salmon transplanted from North America into the Shibetsu River (II).
Nara, K., Shimizu, M., Okukawa, G., Matsumura, K., and Umeda, K. pp. 7-16. (In
Japanese with English summary)(465KB)
Abstract
Coho salmon fry were released into tributaries of the
Shibetsu River in 1977 and 1978. Most coho fry dispersed downward within 2-3 km
from the release point. In the tributaries where channel was altered by
straightening and logging, juveniles could not survive over the first summer,
because of high water temperature over 25°C. Juveniles mainly fed on aquatic
insect larvae during summer and autumn. The diet was as same as that of
sympatric juvenile masu salmon. In winter, juvenile coho salmon stayed in a pool
with covers such as scored bank and vegetation.
- 33-3
Studies on the effect of bathing drugs to salmonid fishes-I. Bathing toxicity of
nifurpirinol to chum salmon and kokanee fry. Nomura, T., and Shimizu, I. pp.
17-23. (In Japanese with English summary)(336KB)
Abstract
Toxicity of nifrupirinol (NFP) to
chum salmon and sockeye salmon fry was studied using Franece granule. A normal
use of NFP (0.5-1.0 ppm) showed no toxicity for salmon fry (body weight 0.3-3.9
g).
- 33-4
A
research on chum fingerlings for stocking-I.
Hashimoto, S. pp. 25-30. (In
Japanese with English summary)(221KB)
Abstract
The author investigated the
survival rate, physical structure and body composition of chum salmon fry
transferred in seawater. Thin chum fry showed a tendency to die in the seawater
challenge test. The condition factor of most dead fry in seawater was less than
7.0. Percentage of thin chum fry whose condition factor was less than 7.0 was
0-46% in the Chitose River. The protein content of these thin chum fry was lower
than that of normal fry.
- 33-5
Studies on a growth and feeding habit of the chum salmon fry during seaward
migration in the Tokachi River System-II. Aquatic fauna in the Tokachi River
System during months of March to July in 1977. Kaeriyama, M. pp. 31-45. (In
Japanese with English summary)(574KB)
Abstract
Fauna and standing crop of aquatic
animal community were examined in the Tokachi River System in the spring of
1977. At a location with stable flow and river beds, the benthic animal
community had an abundant standing crop, and was dominated by Stenopsychidae and
Hydropsychidae. There was no obvious relationship in abundance between benthic
and drifting animal communities. The standing crop of drifting animal occupied
dominantly by Chironomidae, and Capniidae were very abundant from late March to
early April.
- 33-6
Studies on a growth and feeding habit of the chum salmon fry during seaward
migration in the Tokachi River System-III. Relationships between migration time
and the growth or the feeding behavior of the fry during 1977. Kaeriyama,
M., and Sato, S. pp. 47-73. (In Japanese with English summary)(1,334KB)
Abstract
Seaward migration, growth, and
feeding behavior of chum salmon fry were ecologically examined in the Tokachi
River System from February to July in 1977. Only a few fry released initially
from hatchery in early spring remained in the river for several months with
large body size (40-80 mm in fork length). However, numerous fry (30-40 mm in
fork length) migrated seaward immediately after the release. Their stomach
contents corresponded with the drifting animal community, indicating that chum
fry had no selectively on a specific prey in the river.
- 33-7
The
spotless rainbow trout (Salmo gairdneri) collected in the Nishitappu
River, southwestern coast of Hokkaido, Japan. Hikita, T. pp. 75-78. (In
Japanese)(1,433KB)
Abstract
Eight abnormal rainbow trout were captured in the
Nishitappu River along the Pacific coast of Hokkaido. These fish had no parr
mark on the body nor black spots in the fins. They might originate from "hourai
masu", a race of rainbow trout bred in Aichi Prefecture.
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-
Sci. Rep. Hokkaido Fish Hatchery
(32), 1978
-
32-1
Studies on the Pacific salmon in the Yurappu River and Volcano
Bay 3. On the returning of pink salmon. Kobayashi, T., Abe,
S., and Ozaki, Y. pp. 1-8. (In Japanese with English summary)(496KB)
Abstract
Pink salmon were transplanted in
the Yurappu River from the Iwaobetsu and Nishibetsu rivers in
1965 and 1966, respectively. Pink salmon fry reared in spring
water were released in the early March of 1965 and late March of
1966, while pink fry reared in stream water were released in the
late April of 1965 and 1966. There was no difference in growth
between the spring and stream groups. Almost all fry migrated
seaward within 2 days after release. Homing migrations of adult
pink salmon were observed in the Yurappu River. In two groups
reared in spring water, the return rate was higher in the fish
group released in late March than in early March. The number of
adult returns per spawner was estimated 2.24 fish in 1966 and
2.06 fish in 1967.
- 32-2
Ecological observation on the adult salmon-II. Diurnal variation
of upstream migration of the adult chum salmon in the Chitose
River. Mayama, H. pp. 9-18. (In Japanese with English
summary)(540KB)
Abstract
Diurnal variation in the upstream
migration of adult chum salmon was observed at the Nishikoshi
Catching Station in the Chitose River, a tributary of the
Ishikari River, during the autumn of 1976 and 1977. It was
estimated that their upstream migration was essentially inactive
in the daytime, while it became active at dawn or dusk when
there was inconsiderable fluctuation of the water flow. The
active movement of adults was also caused by turbidity of stream
water. The examination of sex composition on plural fishes
caught in every basket of fish wheel suggested that the
couplings were already formed in the majority of ascending adult
salmon at the catching station.
- 32-3
Studies on the retention of gametes of salmonid fishes-3. Change
in fry-liberation rate of stored chum salmon eggs inseminated
with sperms preserved in same conditions. Hiroi, O. pp.
19-26. (In Japanese with English summary)(545KB)
Abstract
Eggs and sperms of chum salmon
were shut tight in each plastic bag with oxygen and stored in
corrugated cardboard box at the hatchery room at 2-9°C. Stored
eggs were inseminated with sperms preserved in same conditions
at various periods of storage. Motility of the spermatozoa
preserved was examined in the distilled water at the various
periods of storage under a light microscope.
- 32-4
Studies on a growth and feeding habit of the chum salmon fry
during seaward migration in the Tokachi River System-I.
Influence of thaw on a growth and feeding habit of the fry.
Kaeriyama, M., Sato, S., and Kobayashi, A. pp. 27-41. (In
Japanese with English summary)(832KB)
Abstract
Growth and feeding habit of chum
salmon fry during seaward migration were examined in the Tokachi
River System in the springs of 1975 (remarkable thaw) and 1976
(indistinct thaw). Water temperature and turbidity in 1975 were
higher and less than those in 1976, respectively. The body size
of 1976 chum fry was 1.0-1.3 times in fork length and 1.0-3.1
times in body weight larger than that of 1975 fry. The average
stomach content of 1976 fry was about 4 times as much as that of
1975 fry. Most of chum fry dominantly fed on chironomids in
Diptera in both 1975 and 1976. Chum salmon fry in the spring of
1975 might not stay to grow up by an extreme thaw.
- 32-5
Pathological studies on the brood rainbow trout died after
egg-stripping-II. Occurrence of Aeromonas salmonicida.
Nomura, T. pp. 43-48. (In Japanese with English summary)(299KB)
Abstract
Occurrence of Aeromonas
salmonicida was examined for the kidney of rainbow trout (n=557)
after egg stripping from 1974 to 1976. Percentage of fish with
the agent was 18.6% in 1974, 42.6% in 1975, and 15.9% in 1976.
The organism varied from 2.08 x 102 to 1.00 x 108
per gram. The number of bacteria in the kidney and spleen was
higher than in the liver.
- 32-6
Feeding habit of adult kokanee salmon (Oncorhynchus nerka)
in Lake Shikotsu. Mayama, H. pp. 49-56. (In Japanese with
English summary)(429KB)
Abstract
Stomach contents of lacustrine
sockeye salmon (n=188) caught by gill net in Lake Shikotsu from
January 1977 to December 1977 were examined to determine their
feeding habit. The food organism was composed of 4 species of
crustacean plankton, larvae and pupae of chironomid, pupae of
caddis fly, larvae of may fly, palaemoid shrimp, fish larva and
terrestrial insects. Crustacean plankton was the most important
food in all seasons. Dominant species of food plankton was
Daphnia longispina in winter and spring, and
Acanthodiaptomus pacificus in summer and autumn. Aquatic
insects, mainly chironomid, and terrestrial insects became
important food in spring and summer. When the principal food
plankton suddenly disappeared in the summer and autumn of 1977
(see Ishida 1978; 32-7), neritic and benthic plankton (Alona
affinis and Chydorus sphaericus) replaced as major
foods for lacustrine sockeye salmon in the lake.
- 32-7
On the abundance of plankton crustaceans in Lake Shikotsu during
1974-1977. Ishida, T. pp. 57-60. (In Japanese)(168KB)
Abstract
Seasonal changes in abundance of
zooplankton were examined in Lake Shikotsu between 1974 and
1977. Acanthodiaptomus pacificus (Copepoda) disappeared
from the lake by the early autumn of 1977. Simultaneously
abundance of cladocerans (Daphnia longispina and
Bosmina longirostris) changed as in 1950's: a reduction of
D. longispina and an increase of B. longirostris.
- 32-8
A hermaphroditic chum salmon, Oncorhynchus keta, from the
Chitose River, with a example of itself-fertilization.
Hikita, T., and Hashimoto, S. pp. 61-64. (In Japanese)(2,353KB)
Abstract
The authors examined the serum
protein of a hermaphroditic chum salmon adult captured in the
Chitose River. The serum electorophoretic pattern showed an
existing of female specific protein in the serum. Eggs from this
chum salmon were fertilized with the sperm from the same fish,
and the hatching fry were reared for 138 days. These chum salmon
fry had thin body color, and their parr mark was unclear,
comparing with normal chum fry.
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-
Sci. Rep. Hokkaido Fish Hatchery
(31), 1977
-
31-1
Studies on the Pacific salmon in the Yurappu River and Volcano
Bay 2. On the migration and the growth of the fry during seaward
migration and the return of marked adults. Kobayashi, T.,
and Abe, S. pp. 1-11. (In Japanese with English summary)(611KB)
Abstract
Migration and growth of juvenile
chum salmon during the period of seaward migration in 1965 and
1966 were observed in the Yurappu River. Most chum salmon fry
migrated seaward immediately after release. The specific growth
rate of body weight for marked juvenile chum salmon indicated
0.0374 in the river and 0.0392 in the coastal water. There was
no significant difference in the return rate of adults between
the frozen diet-feeding group and no feeding controls.
-
31-2
Feeding of juvenile masu salmon in the stream life.
Hashimoto, S., and Ishida, T. pp. 13-20. (In Japanese with
English summary)(458KB)
Abstract
Feeding habit was observed for
juvenile masu salmon obtained from the Mena River, a tributary
of the Shiribetsu River. A study of feeding activity in masu
salmon was conducted in mid-July, 1975 and 1976. The daily
stomach content index was 5.32 in 1975, and 3.75 in 1976. The
stomach content index changed with amount of drifting organisms,
with partial modification by internal physiological rhythm of
the fish. The food transit rate from the stomach to the
intestine varied with the stomach content index. It was found
that a considerable amount of moisture was absorbed in the
stomach.
-
31-3
Ecological observation on the adult salmon -I. Diurnal variation
of upstream migration of the adult chum salmon in the Chitose
River (1). Mayama, H., and Takahashi, T. pp. 21-28. (In Japanese with
English summary)(498KB)
Abstract
Diurnal variation in the upstream
migration of adult chum salmon was observed at the Nishikoshi
Catching Station of the Chitose River, a tributary of the
Ishikari River, in the October of 1974 and 1975. Their upstream
migration became active principally in daytime. A major factor
controlling their upstream movement might be the fluctuation of
stream flow discharged from the drainage of power plants in the
upper stream.
-
31-4
Biochemical studies of carotenoids in the chum salmon (Oncorhynchus
keta) during up-stream migration for spawning-V. Behavior of
carotenoids in the kokanee (O. nerka) with the
advancement of maturation. Kitahara, T., and Saito, K. pp.
29-36. (In Japanese with English summary)(436KB)
Abstract
Characteristics of carotenoid
pigments were compared between chum and lacustrine sockeye
salmon. With an advancement of maturation, both species showed
the same changes in the quantity of carotenoid pigments in the
muscle, skin and gonad. At the immature period, astaxanthin
mainly accumulated in the muscle was moved to the skin and
gonads in female and male, respectively. Muscle carotenoids
consisted of astaxanthin, zeaxanthin and lutein. With an
advancement of maturation, the total muscle carotenoids
decreased, and specially the composition of astaxanthin
decreased in the muscle carotenoids. The component carotenoids
of the gonads were the same as those of the muscle. Skin
carotenoids contained astaxanthin, lutein and flavoxanthin.
-
31-5
Studies on the effective promotion of artificial salmon
production in the Tokachi River System-I. Utility and
surrounding conditions in the chum salmon production of the
Utsunai Holding Pond. Kaeriyama, M., and Kobayashi, A. pp.
37-53. (In Japanese with English summary)(987KB)
Abstract
In the autumn of 1974 and 1975,
rearing environment and mature condition of adult chum salmon
were examined in the Utsunai Holding Pond of the Tokachi River
System. A significant negative relationship between water
temperature and survival of female adults was observed in the
holding pond. In addition, it was suggested that the survival of
female adults might be affected by stress and water flow.
-
31-6
Studies on the effective promotion of artificial salmon
production in the Tokachi River System-II. Escapement and
catching or spawning procedures of the chum salmon in the
Tokachi River System during 1976. Kaeriyama, M. pp. 55-70.
(In Japanese with English summary)(3,945KB)
Abstract
Escapement trend and artificial
fertilization procedures of adult chum salmon were examined in
the Tokachi River during the autumn of 1976. Most adults were
captured from late September to October. A significant negative
relationship was found between ascending time of adults and
their maturing period (days from capture to fertilization).
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