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Vol.01-10
No.11-20 No.21-30
No.31-40
No.41-50
No.11 No.12
No.13 No.14
No.15 No.16
No.17 No.18
No.19 No.20
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Sci. Rep. Hokkaido Fish Hatchery
(20), 1966
- 20-1
Ecological observation on the salmon of Nishibetsu River II. The
moving, growth and feeding habit of pink salmon fry,
Oncorhynchus gorbuscha (Walbaum), during seaward migration.
Kobayashi, T., and Harada, S. pp. 1-10. (In Japanese with
English summary)
 (595KB)
Abstract
Seaward migration and feeding
habits of pink salmon fry were investigated in the Nishibetsu
River during the spring of 1963. Pink salmon fry released from a
hatchery in late December and January migrated seaward from
February to March, although wild pink fry moved to the sea from
April to June. The examination of the stomach contents of pink
fry during their seaward migration revealed very small amount of
diets. It is concluded that river productivity rarely affect
pink salmon fry. Thus the coastal environment may be important
for the successful artificial enhancement of pink salmon.
- 20-2
A growth pattern of scales of juvenile masu salmon (Oncorhynchus
masou) during smolt metamorphosis. Kubo, T. pp. 11-20.
(In Japanese with English summary)(8,472KB)
Abstract
The growth of scales of juvenile
masu salmon during smoltification was observed in relation to
their seaward migration. Usually, a slight silverization of the
body color as an external sign of smolt metamorphosis begins in
wild fish in late October. Remarkably, this is accompanied by
the formation of rather broad circuli abruptly added on the
outside of the narrow ones. These broad circuli are not easily
distinguishable from the widely spaced circuli formed during
their seawater life. However, their number slowly increased in
contrast to that in the parr life, and by early May only three
to five circuli are manifested. When the fish reach at the post-smolt
phase, this action becomes suddenly rapid. By mid May, five to
seven circuli can be counted. It is very likely that the marked
features in this growth pattern of the scales are associated
with the occurrence and progress of smolt metamorphosis.
Further, it is interesting that the serum phosphorus
concentration tends to increase at the time of formation of the
broad circuli.
- 20-3
A hematological study of chum salmon (Oncorhynchus keta)
during up-stream migration for spawning-I. Nishino, K. pp.
21-25. (In Japanese with English summary)(235KB)
Abstract
Blood characters were examined for
adult chum salmon during their upstream migration and holding
period. Number of erythrocyte, hematocrit value, hemoglobin, and
serum protein were measured. During the development of fish
maturation, no changes were found in erythrocytes, hematocrit
value, and hemoglobin, but a significant difference was detected
in serum protein.
- 20-4
Studies on the metabolic function of young chum salmon
Oncorhynchus keta (Walbaum)-I. The type and quality of
manufactured diets for the rearing of fingerlings.
Hashimoto, S. pp. 27-35. (In Japanese with English summary)(2,688KB)
Abstract
Chum salmon fry were reared for
three months under four different feeding series. It was
indicated that the type and quality of manufactured diets were
important. At the beginning of feeding, it seemed that chum
salmon fry preferred the paste diet better than the fortified
grain diet. However, they died 2 months after the start of
rearing when the moisture in the diet became too little as in
fortified grain diet. The death was supposed to be caused by a
lack of water for special metabolic functions. In the case of
using the manufactured diets for the rearing of chum salmon fry,
it is necessary to make clear the mutual relations between
nutritional constituents and physiological function.
- 20-5
Studies on the metabolic function of young chum salmon,
Oncorhynchus keta (Walbaum)-II. The influence of water
quantity and the amount of the food, and fish size on efficiency
of food conversion and growth of rearing fingerlings with
manufactured diets. Hashimoto, S. pp. 37-45. (In Japanese
with English summary)(553KB)
Abstract
The purpose was to determine the
influence of initial fish size, inflow water, and food on the
growth of chum salmon fry, and the efficiency of food conversion
by feeding with manufactured diets. Fish size, rather than
inflow water quantity mainly affected the efficiency of food
conversion. A relation between the food efficiency and fish size
was shown by a linear formula. The food efficiency was
remarkably affected by the amount of diet as well as the fish
size. Consequently, it is necessary to determine a prefer food
level according to fish size as Lietritz's feeding technique.
- 20-6
Studies on the metabolic function of adult chum salmon,
Oncorhynchus keta (Walbaum)-I. Possible amount of the chum
salmon requested for retaining in culture pond and its requisite
conditions, with reference to the oxygen consumption and the
metabolic excretions. Hashimoto, S. pp. 47-64. (In Japanese
with English summary)(1,741KB)
Abstract
Oxygen, free carbon dioxide, and
ammonia nitrogen concentrations were monitored in ponds holding
adult chum salmon. In all experimental aquaria, adult chum
salmon showed immediately high metabolic rate, and then the rate
became stable. These changes occurred distinctively in the
aquarium supplied with abundant water. The mortality of chum
adults held in ponds was higher in the early runs than in the
late runs.
- 20-7
Survey of the aquatic insect fauna of the Tokachi River System.
Kawai, T. pp. 65-81. (In Japanese with English summary)(7,232KB)
Abstract
Benthos fauna was investigated at
16 locations in the Tokachi River watershed in the August and
October of 1964. The main fauna was composed of larvae and
nymphs of caddies, may flies, and midges. The standing crop was
highest at Otofuke-bashi of the Otofuke River in summer.
However, they decreased in autumn because of the industrial
pollution. Biological indicators suggested that the benthos
fauna in the Otofuke and Obihiro rivers were influenced by
industrial water pollution.
- 20-8
Water characteristics of the River Tokachi-gawa and its
tributaries. Tokui, T. pp. 83-89. (In Japanese with English
summary)(296KB)
Abstract
The degree of water pollution was
evaluated in the Tokachi River Systems from the summer of 1964
to the early spring of the next year. The Obihiro River was most
polluted, rich in COD, BOD, and suspensions, because of sewage
from Obihiro City and dairies in its environs. From the autumn
to the early winter when beet-sugar and potato-starch factories
were operated, the lower river reaches had high degree of BOD
and suspensions due to waste water from these factories.
- 20-9
Research on the death of salmon in the Tokushibetsu River III.
Takayasu, M. pp. 91-106. (In Japanese with English summary)(920KB)
Abstract
An investigation was intended to
arrest the death of adult chum salmon in the Tokushibetsu River
caused by waste waters from the Motokura metal mine along the
upstream of the river. The cause of damages for fishes was
poisonous heavy metal salts contained in the mine waste waters.
- 20-10
Limnological reconnaissance of Lake Chimikepp, eastern Hokkaido,
Japan. Tokui, T. pp. 107-118. (In Japanese with English
summary)(6,417KB)
Abstract
The present paper is a record of
limnological reconnaissance of Lake Chimikeppu, a small lake
situated on the east highlands of Hokkaido. Japanese kokanee
salmon (=lacustrine sockeye salmon?) had been indigenous to this
lake, but their original form was lost since the transplant of
allied form from Lake Shikotsu. The type of this lake is
mesotrophic. It is one of lakes that deserve the future
protection, because the natural characteristics have been well
preserved.
- 20-11
Some ecological studies on the kokanee salmon (O. nerka
var. adonis) in Lake Shikotsu, Hokkaido -IV. Notes on the
growth and adult scale in 1952-1956. Kurohagi, T., and
Sasaki, S. pp. 119-142. (In Japanese with English summary)(14,092KB)
Abstract
The authors studied on the scale
growth and age of lacustrine sockeye salmon from 1952 to 1956 in
Lake Shikotsu, Hokkaido. A group of salmon which hatched from
eggs spawned in the autumn of 1948, returned as a principal
spawning group of adult male of 8 years old were scarce in 1956,
but females of the same group were dominant. These females had
abnormal ovaries of diminutive type. The abnormal growth with
the diminutive size was observed until the summer of 1952, and
the growth of scale and body was not found, because of low
abundance of crustacean plankton.
- 20-12
On the chinook salmon matured in a tank of the Otaru Aquarium.
Hikita, T. pp. 143-145. (In Japanese)(3,155KB)
Abstract
Juvenile chinook salmon (1+)
introduced from Washington State, USA, were reared in a
saltwater tank at Otaru Aquarium. The fish became almost matured
after three years, but accidentally died in July 1965. The
morphology was described in this paper.
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Sci. Rep. Hokkaido Fish Hatchery
(19), 1965
- 19-1
Ecological observations on the salmon of Nishibetsu River 1. The
migration and growth of chum salmon fry, Oncorhynchus keta
(Walbaum). Kobayashi, T., Harada, S., and Abe, S. pp. 1-10.
(In Japanese with English summary)(466KB)
Abstract
Seaward migration of chum salmon
fry was investigated in the Nishibetsu River during the spring
of 1963. Although chum fry slowly moved downstream until March,
they quickly migrated seaward when snow melted in April. Marked
chum fry migrated downstream within about 8 days at a distance
of 91 km. They migrated downstream in the daytime when the river
water became muddy, although they commonly moved at night. Chum
fry grew slowly until a peak of migration period, but rapidly
grew with increasing the water temperature from May to June.
- 19-2
On the smolts of the red salmon (Oncorhynchus nerka) at
Urumobetsu, Etorof I., Kuril Islands. Watanabe, M. pp.
11-23. (In Japanese with English summary)(2,313KB)
Abstract
Sockeye salmon occur in Lake
Urumobetsu on Iturup Island, maybe the southern limit of the
natural spawning distribution in Asia. Morphology and age of
sockeye salmon smolts were investigated in this lake between
1940 and 1941. A total of 183 smolts was captured in the
Urumobetsu River in July and August. Most smolts (95-98%) were
3years old (2+), whose total body length was 118 mm in average.
As for the sex ratio of smolts, male was more abundant than
female in 1940, but fewer in 1941.
- 19-3
On the influence of temperature upon the acceleration of
smolt-transformation in juvenile masu salmon (Oncorhynchus
masou). Kubo, T. pp. 25-32. (In Japanese with English
summary)(1,175KB)
Abstract
The author examined effects of
water temperature on the changes of external appearances and
some characteristics of blood of juvenile masu salmon during the
period of smolt transformation. Masu salmon juveniles in the
early period of smolt transformation were reared at the higher
temperature (9-14°C) for about 25 days. As a result of the high
temperature treatment on the fish in the early phase of the pre-smolt
stage, the fish attained to the mid-smolt stage. The same
experiment on the fish which had already reached the latter
phase of the pre-smolt stage showed that the fish attained to
the post-smolt stage after the high temperature treatment. These
results suggest that water temperature might play an important
role in the advancement of smolt transformation in masu salmon
juveniles.
- 19-4
Experiments using air bubbles and the light to deflect migrating
chum salmon fry, Oncorhynchus keta (Walbaum).
Kobayashi, T., and Sasaki, M. pp. 33-42. (In Japanese with
English summary)(5,667KB)
Abstract
To prevent chum salmon fry
straying into artificially constructed channels, effects of air
bubble and lighting for downstream behavior of chum salmon fry
were examined. In night or turbid water, considerable fry were
found to avoid a screen of air bubbles. Lighting also
intercepted their downstream migration at night by swarming the
fry under the light.
- 19-5
Observations on the marking adult chinook salmon recaptured in
the Tokachi River and the young in the Hidaka coast, Hokkaido,
Japan. Hikita, T. pp. 43-47. (In Japanese with English
summary)(2,554KB)
Abstract
Chinook salmon eggs were
transplanted from Washington State to hatcheries of Hokkaido for
five years. The juvenile chinook salmon were released to the
Tokachi River in every spring of 1960-64. Sixteen adult chinooks
were recaptured in the Tokachi River in the fall of 1963 and
1964. A large maturing female (91.8 cm in total length (TL)) was
caught on September 22, 1964. From the scale reading its age was
estimated five years. The number of eggs was about 5,900. The
origin of this marked specimen was 1960-released group.
Twenty-five young chinooks (22.7-30.8 cm in TL) were also caught
along the Hidaka coast in the fall of 1964, suggesting that
chinooks stayed in the coast for a long period.
- 19-6
Physical and chemical characteristics of Lake Shikotsu-ko,
Hokkaido, Japan. Tokui, T. pp. 49-59. (In Japanese with
English summary)(622KB)
Abstract
Lake Shikotsu is a large, deep and
clear caldera lake of the southwestern Hokkaido, where
lacustrine sockeye salmon ("himemasu") has been transplanted.
The maximum surface water temperature is 20-21°C in summer, and
the minimum is 2-3°C in winter. The bottom water is always less
than 4°C throughout the year. Since the oxygen content in
hypolimnion is rich in summer, the lake is classed as
oligotrophic. The water is moderately hard and slightly alkaline
(pH 7.0-8.0). It is interesting that the dissolved phosphate was
absent in the summer of 1962 when salmon harvest was highest in
recent years.
- 19-7
Some ecological studies on the kokanee salmon (O. nerka
var. adonis) in Lake Shikotsu, Hokkaido -III. Note on the
growth and age of adult scale in 1949-1951. Kurohagi, T. pp.
61-74. (In Japanese with English summary)(7,176KB)
Abstract
The present paper reported the
somatic growth and age of adults of lacustrine sockeye salmon in
Lake Shikotsu from 1949 to 1951. Their growth was relatively
high in 1949 and 1951, but poor in 1950. The spawners were
composed by 5 and 6 year fish in 1949, but by almost only 5 year
fish in 1950 and 1951.
- 19-8
Some cases of the anomalous coloration of the pink salmon,
Oncorhynchus gorbuscha (Walbaum), caught in the North
Pacific Ocean. Hikita, T. pp. 75-77. (In Japanese)(1,474KB)
Abstract
The author reported the
morphological characteristics of pink salmon (age 0.1; n=3) with
anomalous body coloration, captured in the high seas of the
North Pacific Ocean in June 1964.
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Sci. Rep. Hokkaido Fish Hatchery
(18), 1964
- 18-1
An ecological study on the salmon fry, Oncorhynchus keta
(Walbaum)-VII. Note on the behaviour of the fry to their seaward
migration. Kobayashi, T. pp. 1-6. (In Japanese with English
summary)(325KB)
Abstract
Seaward migration of chum salmon
fry was investigated in the Chitose River. Most fry migrated
downstream in surface area near the bank within 2-3 hours after
the sunset. The distribution of chum salmon fry might not be
closely related with the river current speed. Their migration
was decreased by bright moonlight.
- 18-2
An ecological study on the salmon fry, Oncorhynchus keta
(Walbaum)-VIII. The growth and feeding habit of the fry during
seaward migration. Kobayashi, T., and Ishikawa, Y. pp. 7-15.
(In Japanese with English summary)(449KB)
Abstract
Growth and feeding habit of chum
salmon fry were investigated in the Chitose and Ishikari Rivers
from February to June in 1961. In the rivers chum salmon fry
grew slowly between March to April at a peak of seaward
migration, but did rapidly from May to June. The dominant
species in the stomach content was chironomids. Feeding
selectivity was not found during the study period. The stomach
content index of fry was higher in upper and middle reaches than
in lower one.
- 18-3
Downstream migrants of chum salmon in the Yufutsu River (1).
Remaining periods and growth of fry in the Utonai Lake.
Sakano, E. pp. 17-25. (In Japanese with English summary)(470KB)
Abstract
Downstream migration and residency
of chum salmon fry were investigated in the Bibi River and Lake
Utonai. Fin-clipped fry were released to the Bibi River flowing
into Lake Utonai. The fry migrated dawn to the Lake Utonai
within several days after release, where they stayed for two or
three weeks, during which period their fork length increased
16-20 mm.
- 18-4
Research on the death of salmon in the Tokushibetsu River (I).
Takayasu, M., Eguchi, H., Kimura, G., and Hayasaka, S. pp.
27-39. (In Japanese with English summary)(783KB)
Abstract
Since the spring of 1961, a large
number of chum salmon fry died in the lower reach of the
Tokushibetsu River. The estimated total number of deaths was
about 12,000 in 1961, and 20,000 in 1962. A preliminary research
estimated that the cause would come from certain toxic
substances contained in waste water from Motokura Metal Mine
situated on the upstream of river.
- 18-5
Research on the death of salmon in the Tokusibetsu River (2).
Takayasu, M., and Kimura, G. pp. 41-55. (In Japanese with
English summary)(740KB)
Abstract
The water hardness was extremely
low in the Tokushibetsu River. The hardness was always less than
0.7°dH in the river. The authors investigated the toxicity of
copper, zinc, and lead on chum salmon fry held in waters at
hardness of 0.7°dH. The median tolerance limit (TLM48)
of copper was 0.025-0.035 ppm, whereas the minimum lethal dose
was about 0.001 ppm. The copper concentration of the river water
was about 0.0058-0.012 ppm. Thus it became clear that chum
salmon fry were killed by copper contained in the river water
with low hardness.
- 18-6
Biological study on hybrids of the salmonid fishes. A note of F1
hybrids between chum (Oncorhynchus keta) and pink salmon
(Oncorhynchus gorbuscha). Hikita, T., and Yokohira,
Y. pp. 57-65. (In Japanese with English summary)(523KB)
Abstract
Reciprocal cross between chum and
pink salmon was carried out, and hybrid fry were released in the
Horonai River. Hybrid eggs between chum female and pink male
(CP) showed more than 92% survival until hatching, but the
survival rate of hybrids between pink female and chum male (PC)
was lower (81-91%) than that of the CP fish. Yolk absorption and
growth of the CP fry was faster than that of the PC fry. About a
half of the CP fry showed abnormal blue or dark green body
coloration, although the PC fry were normal. The parr mark was
observed in all PC fry, but absent in a part of the CP fry.
- 18-7
Biological study on hybrids of the salmonid fishes. Cytological
observation on fertilization in the cross between the chum
salmon and the pink salmon. Kobayashi, H. pp. 67-72. (In
Japanese with English summary)(6,380KB)
Abstract
Eggs crossed reciprocally between
chum salmon and pink salmon were observed cytologically. Eggs of
the both crossing fertilized and cleavaged in normal without
poly-spermic. Although eggs of chum salmon fertilized by pink
salmon sperm took a little longer time until the first cleavage
than that of the other crossing, the both hybrid eggs developed
in almost same manner. Pronucleus coupled 2-3 hours after
insemination at 14-16°C. This suggests that eggs are sensitive
for handing in the period.
- 18-8
Studies on the kokanee salmon (V). Transplantations of the
kokanee salmon in Japan. Tokui, T. pp. 73-90. (In Japanese
with English summary)(14,257KB)
Abstract
"Himemasu" (lacustrine sockeye
salmon) in Lake Akan were transplanted to about 16 lakes in
Japan since the first transplant to Lake Shikotsu in 1894. It is
difficult to introduce "himemasu" in lakes whose minimum surface
water temperature is higher than 5°C. It is presumed that "himemasu"
transplant into acidotrophic lakes results into a complete
failure. Introduced Japanese smelt (Hypomesus nipponensis)
competes with "himemasu", and may cause a decrease of "himemasu"
stocks. It is a burden that "himemasu" eggs and juveniles are
preyed by other salmonids such as masu salmon, rainbow trout and
whitespotted charr.
- 18-9
Some ecological studies on the kokanee salmon (O. nerka
var. adonis) in Lake Shikotsu, Hokkaido-II. Some
observations on the growth of scale. Kurohagi, T., and
Sasaki, S. pp. 91-111. (In Japanese with English summary)(12,626KB)
Abstract
Scale growth patterns were
examined for lacustrine sockeye salmon "himemasu" caught in Lake
Shikotsu in 1957-1961. An increase of the scale circuli was
accompanied with the fish growth. Yearly fluctuations in the
development of circuli and radius at each year class occurred,
and the maximum increase was found in the 2nd or 3rd year of
life.
- 18-10
On the recent distribution of two small cyprinid fishes,
Pseudorasbora parva pumila (Miyadi) and P. parva parva
(Temmink and Schlegel) in Hokkaido Island, Japan. Hikita, T.
pp. 113-116. (In Japanese with English summary)(234KB)
Abstract
Geographical distribution and
morphology of top mouthminnow (Pseudorasbora parva) and
dwarf topmouth minnow (P. pumila pumila) in Hokkaido were
reviewed. Top mouth minnow was recorded in lower region of the
Ishikari River, and a pond of Otaru. Dwarf topmouth minnow was
recorded in a pond of Hakodate and the Tokachi River.
- 18-11
Hanamagari-seppari-masu in local name collected from Lake
Motosu, Yamanashi Prefecture, Japan. Tokui, T., and Hikita,
T. pp. 117-119. (In Japanese)(3,015KB)
Abstract
Large adult kokanee salmon (=lacustrine
sockeye salmon?), which was called "hanamagari-seppari-masu",
was captured in Lake Motosu near Mt. Fuji, central Honshu. The
author described the morphology of two specimens. They were male
with large head and body height, and 42 and 37 cm in body
length.
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Sci. Rep. Hokkaido Fish Hatchery
(17), 1962
- 17-1
Ecological and morphological studies of the genus
Oncorhynchus (Salmonidae) with particular consideration on
phylogeny. Hikita, T. pp. 1-97.(16,870KB)
Abstract
Pacific salmon was investigated
based on morphology, ecology, and phylogeny, and was divided
into two groups. A-stem includes smart body fish such as chum,
pink, and sockeye salmon, and B-stem covered biwamasu, masu,
coho, and chinook salmon. The A-stem was more derived than the
B-stem.
- 17-2
A note on the plankton of Kurilskoe Lake, southern Kamchatka
Peninsula, collected in early August 1961. Kurohagi, T. pp.
99-105. (In Japanese with English summary)(553KB)
Abstract
A total of 19 species was
identified from a sample obtained by a vertical net hauling from
150 m layer to surface in Lake Kuril, a large and deep volcanic
lake in southern Kamchatka Peninsula, in the early August of
1961. The zooplankton consisted of 10 species: Cyclops
scutifer, Daphnia longiremis, Keratella cochlearis
var. macracantha, K. quadrate, Notholca
squamula, Asplanchna priodonta, Filinia longiseta,
Kellicottia longispina, Polyarthra longiremis, and
Synchaeta sp. The phytoplankton consisted of 9 species:
Melosira italica, M. varians, M. granulata
var. angustissima, Stephanodiscus altinus,
Fragilaria spp., Synedra ulna var. danica,
S. acus, Cymbella ventricosa, and C. cistula.
Melosira italica was the most dominant species, and
Cyclops scutifer was followed.
- 17-3
Chum salmon tagging experiments in spawning streams of Hokkaido
(III). Experiments in Nishibetsu River (2). Nishino, K., and
Harada, S. pp. 107-109. (In Japanese with English summary)(193KB)
Abstract
This paper reported the results of
1960 and 1961 tagging experiments on adult chum salmon in the
Nishibetsu River along the Nemuro Straits of eastern Hokkaido.
Tagged salmon were released from the mouth of the Nishibetsu
River, and recovered at Juyonsen Catching Station. The distance
from released point to catching place was about 12 km. The
overall tag recovery was 69.6% in 1960 and 66.8% in 1961.
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Sci. Rep. Hokkaido Fish Hatchery
(16), 1961
- 16-1
Biology of chum salmon, Oncorhynchus keta (Walbaum), by
the growth formula of scale. Kobayashi, T. pp. 1-102. (In
Japanese with English summary)(16,685KB)
Abstract
Scale pattern and formation were
examined for chum salmon collected from the Ishikari River and
North Pacific Ocean in order to evaluate usefulness of scales
for the age determination, growth estimation, and stock
identification. A growth check, that was a band of narrowly
spaced or discontinuously formed circuli, was formed in winter.
The age determination could be performed using these growth
checks. The scale radius and scale pattern were affected by
somatic growth. Back-calculated annual growth decreased with
aging of fish. Although the age composition of adult chum salmon
were fluctuated annually in the Ishikari River in 1950-1958,
their body size and scale pattern were not variable. The stock
identification of chum salmon in the North Pacific Ocean was
performed using the age composition, number of circuli, and
back-calculated body size. The results of stock identification
were almost consistent with those of tagging experiments,
proving the validity of scale reading method for the stock
identification of high-seas chum salmon.
- 16-2
Anaesthetizing experiments of chum salmon fry with tricaine
methanesulfonate (M.S. 222). Sakano, E. pp. 103-106.(191KB)
Abstract
For the purpose to immobilize
salmon fry for marking, tricaine methanesulfonate (MS-222) was
used instead of ethyl carbamate (urethane). The present study
was undertaken to determine available concentration and duration
of MS-222 for chum salmon fry at 9.5°C. The concentration from
1:22,500 to 1:17,500 seemed to be most reasonable for the
purpose.
- 16-3
Some observations on the downstream chum salmon fry (O. keta)
counted in the natural spawning ground at Memu Stream,
1967-1959. Nagasawa, A., and Sano, S. pp. 107-125. (In
Japanese with English summary)(8,861KB)
Abstract
The natural spawning efficiency of
chum salmon in the Memu River, a tributary of the Tokachi River
in eastern Hokkaido, was studied by using a counting trap from
1957 to 1959. Total eggs deposited in the experimental spawning
ground were estimated by the number of spawners and average
fecundity. All downstream migrating chum fry were counted by
counting weir constructed at the lowest part of the experimental
area. The survival rate of chum salmon from egg to fry stage was
estimated from the numbers of spawners, fecundity and descending
fry in the experimental spawning ground. The survival rate
ranged from 16.2% to 34.4%, with 27.6% in average for three
years.
- 16-4
Studies on the kokanee salmon IV. Spawning migration of the
kokanee salmon in Lake Shikotsu, Hokkaido, Japan. Tokui, T.
pp. 127-136. (In Japanese with English summary)(4,225KB)
Abstract
In Lake Shikotsu, "himemasu" (lacustrine
sockeye salmon) migrated to the shores for spawning from early
October (surface water temperature 15-16°C) to early November
(9-10°C), mainly in middle October (13-15°C) in 1951-1960. The
sex ratio of spawners varied year by year, and male was
predominant only in 1952 and 1955.
- 16-5
Some ecological studies on the kokanee salmon (O. nerka
var. adonis) in Lake Shikotsu, Hokkaido-I. Frequent
occurrence of adult salmon with abnormal ovaries in 1956.
Kurohagi, T., and Sasaki, S. pp. 137-143. (In Japanese with
English summary)(465KB)
Abstract
Many "himemasu" (lacustrine
sockeye salmon) adults with abnormal ovary were observed in Lake
Shikotsu from summer to autumn in 1956, when number of adult
returns was a few. These abnormal fish involved complete or
partial atrophic ovaries, although their body size was larger
than that in other years. A lack of food organisms such as
zooplankton might be regarded as a cause.
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Sci. Rep. Hokkaido Fish Hatchery
(15), 1960
- 15-1
On the
chinook salmon eggs, Oncorhynchus tschawytscha (Walbaum), first planted
in Hokkaido, Japan. Hikita, T. pp. 1-6. (In Japanese with English summary)(451KB)
Abstract
In October of 1959, one hundred
thousand eyed eggs of chinook salmon were presented to the Hokkaido Salmon
Hatchery (HSH) on the occasion of the 80th Anniversary of HSH through the
courtesy of the Washington Department of Fisheries. The origin of chinook eggs
was the Dungeness River near Seattle, Washington. About 70,000 eggs were
immediately transported to the Satsunai Hatchery, Tokachi District. The
remainders were reared in the Chitose Hatchery for experimental purpose,
particularly for the study of regeneration and growth of fish.
- 15-2
Studies on the kokanee salmon (III). Fluctuations in abundance of
the spawning kokanee salmon of Lake Shikotsu, Hokkaido, Japan.
Tokui, T. pp. 7-16. (In Japanese with English summary)(1,006KB)
Abstract
"Himemasu" (lacustrine sockeye
salmon) has been propagated in Lake Shikotsu, a deep eutrophic lake
in southwestern Hokkaido. The spawning population annually
fluctuated from 1898 to 1959. These fluctuations might be mainly
caused by low production of this lake. The low productivity appeared
to be dependent on a scarcity of nutrients in the lake. Lake
fertilization could not be effective in the deep eutrophic lake. The
author recommended that biological monitoring must be continued to
determine the optimal population size of "himemasu" in Lake Shikotsu.
- 15-3
Results from marking experiments on young chum salmon in Hokkaido,
1951-1959. Sakano, E. pp. 17-38. (In Japanese with English summary)(1,016KB)
Abstract
A program of marking experiments
on chum salmon fry started in 1951 in Hokkaido to determine the number of
returning salmon to various areas. In 1959 fin-clipped fry were released from
five rivers. The marked adults were captured in limited areas, and the number of
recaptured fish was different considerably by river populations. The present
study confirmed that fish without fins or opercle also occurred in nature.
- 15-4
Marking experiments of young salmon in Hokkaido (VI). Results observed in 1959.
Sakano, E., and Miura, I. pp. 39-46. (In Japanese)(271KB)
Abstract
Recapture records (n=231) of
marked chum salmon in 1959 were summarized in this paper. In may cases, the age
of recaptured adults were not consistent with the released year.
- 15-5
Biological observations of Memu Stream, Tokachi River System. The freshwater
fishes and its environment. Hikita, T. pp. 47-67. (In Japanese with English
summary)(1,684KB)
Abstract
Fifteen freshwater fish species
inhabited in the Memu River, a tributary of the Tokachi River. the stream. Among
them, threespine stickleback (Gasterosteus aculeatus) was most dominant
with a wide distribution. Sculpin (Cottus nozawae), lamprey (Lampetra
reissneri) and Japanese dace (Tribolodon hakonensis) were commonly
collected throughout the year. The predatory fishes harmful to salmon eggs and
fry were four species: sculpin, rainbow trout, masu salmon, and Japanese dace.
Wild chum salmon fry grew faster than hatchery-released fry in this stream.
- 15-6
Biological observations of Memu Stream, Tokachi River System. The damage of
salmon eggs and fry by predaceous fishes. Hikita, T., and Nagasawa, A. pp.
69-83. (In Japanese with English summary)(1,432KB)
Abstract
More than 13,374 fish were
collected during 1955-59 from various parts of the Memu River of the Tokachi
River System. Rainbow trout, land-locked masou salmon, Japanese dace, and
sculpin (Cottus nozawae) fed chum salmon eggs and fry in the stream.
Among these four species, sculpin had highest impact on salmon eggs and fry.
Three years investigations showed that 4-5% of sculpin stomachs contained salmon
eggs or fry.
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-
Sci. Rep. Hokkaido Fish Hatchery
(14), 1959
- 14-1
Application of biological stain for fish study 1. Effectiveness of biological
stain for the study of scale in rainbow trout by injection. Kobayashi, T.
pp. 1-4. (In Japanese with English summary)(2,301KB)
Abstract
Marking experiments have been done
to determine the effectiveness of biological stain for the scale study of fish
by injecting alizarin red S and lead (Pb) acetate to the muscle of rainbow
trout. Three kinds of alizarin red S solution were prepared, namely 1.0% and
0.5% each in 0.67% physiological solution, and 1.0% in distilled water. Pb-acetate
solution was used at 0.1% in distilled water. Partial staining with alizarin red
was successful, but Pb-acetate staining was unsuccessful. In each experiment by
injection of alizarin red, a pink annulus mark with 0.03-0.05 mm width was
clearly observed in scales around the injected part.
- 14-2
Some
studies on the young fish of the "hime-masu" (Oncorhynchus nerka) in Toya
Lake. Watanabe, M. 5-14. (In Japanese with English summary)(838KB)
Abstract
"Himemasu" is the Japanese name of
lacustrine sockeye salmon. The author reported the body size, sex ratio, age,
and feeding and seaward migration habits of young "himemasu" in Lake Toya.
Juveniles fed mainly on Daphnia. Parr marks started to disappear from
juveniles when their total length reached 120 mm. Smolts (2+) migrated seaward
in late June.
- 14-3
A
preliminary study on the effects of environmental factors upon the attainment of
the smolt stage in juvenile masu salmon. Kubo, T. pp. 15-19. (In Japanese
with English summary)(422KB)
Abstract
Influences of light, water
temperature, and depth of rearing pond on the smoltification of juvenile masu
salmon were experimentally investigated. In juvenile masu salmon exposed to
light during night, the mid-smolt characteristics appeared faster than in the
controls under natural light, but a transformation from mid to post-smolt stages
was markedly delayed. Relatively higher water temperature affected the
acceleration of metamorphosis in fish. Particularly the post-smolt features in
fish reared at high temperature appeared earlier than in those reared at low
temperature. Smoltification of fish reared in shallow water tended to be delayed
in comparison with those reared in deep water.
- 14-4
The
ecology and propagation of genus Oncorhynchus found in northern Japan.
Sano, S. pp. 21-90. (In Japanese with English summary)(7,150KB)
Abstract
Ecology and artificial enhancement
of Pacific salmon in Japan were systematically studied. The accuracy of salmon
homing was evaluated by marking release of chum salmon. A spawning ecology of
chum salmon was elucidated in detail. Furthermore, aspects of artificial salmon
enhancement in Japan were summarized.
- 14-5
Some
biological observations on the rainbow trout, Salmo gairdneri irideus, in
the Nishibetsu River, with special reference to the consumption of salmon eggs
and fry by predaceous fishes. Hikita, T., Kameyama, S., Kobayashi, A., and
Sato, Y. pp. 91-121. (In Japanese with English summary)(2,100KB)
Abstract
Among 13 fish species occurring in
the Nishibetsu River, the predatory fishes to chum salmon egg and fry were 6
species: masu salmon, Japanese dace (Tribolodon hakonensis), whitespotted
charr (Salvelinus leucomaenis), Sakhalin taimen (Hucho perryi),
rainbow trout, and brook trout (S. fontinalis). The damage of chum salmon
eggs by predation was most serious in the middle reaches. The average loss by
predation for three years (1953-55) estimated 29.8% for eggs and 18.4% for fry.
- 14-6
Chum
salmon tagging experiments in spawning streams of Hokkaido (II). Experiments in
Nishibetsu River (1). Nishino, K., Yoneda, Y., and Harada, S. pp. 123-133.
(In Japanese with English summary)(506KB)
Abstract
This report presented results of
1957 and 1958 tagging experiments for adult chum salmon migrating upstream in
the Nishibetsu River, eastern Hokkaido. The overall percentage tag recovery was
23.3% in 1957, and 17.6% in 1958. The conditions for tag recovery were better in
1957 than in 1958. The percentage of tag recoveries was low in September, peaked
in October, and suddenly decreased in late October. Early run salmon showed a
slow upstream migration, while the late runs did a fast migration. There were no
significant differences in the rate of tag recoveries among three tag types used
(harpoon, strap and spaghetti tags).
- 14-7
Marking experiments of young salmon in Hokkaido (V). Results observed in 1958.
Sakano, E., and Miura, I. pp. 135-155. (In Japanese)(701KB)
Abstract
Records of adult recaptures of
marked salmon in 1958 was summarized (n=708). Marked chum salmon released in the
Tokoro River in 1954 were recaptured as adult (5 years old) in 1958. The origin
was not determined for the large number of recaptured chum salmon (more than 80%
of total fish recaptured).
- 14-8
Prevention of upstream migration of adult salmon by electromechanical weir.
Suetake, T. pp. 157-167. (In Japanese with English summary)(2,059KB)
Abstract
A fish catching weir was improved
to avoid adult salmon escapement in river flood. The weir had a electric
shocking (95-135 V) equipment at the upstream end. The author observed that the
weir prevented the upstream migration efficiently when flood water sunk it.
- 14-9
Studies on the kokanee salmon in Lake Towada, northern Honshu, Japan (II).
Climatic and hydrologic factors. Tokui, T. pp. 169-192. (In Japanese with
English summary)(4,568KB)
Abstract
Climate and limnological factors
relating with "himemasu" (=lacustrine sockeye salmon) were investigated in Lake
Towada in northern Honshu. The temperature of lake surface water recorded
maximum (22.4-22.9°C) in August, and minimum (1.2-1.9°C) in March. Young sockeye
salmon were distributed in the surface layer in middle June, and migrated into
the deep layer when the water temperature increased in summer. Maturing salmon
migrated in the surface layer in late autumn. These observations suggest that
the optimum temperature might be 10-13°C for lacustrine sockeye salmon.
- 14-10
On the
plankton of Lake Chimikeppu-ko in eastern Hokkaido. Kurohagi, T. pp.
193-210. (In Japanese with English summary)(8,385KB)
Abstract
Plankton communities were
investigated in Lake Chimikeppu, which was one of habitats for original "himemasu"
(maybe lacustrine sockeye salmon). A total of 94 species of zooplankton and
phytoplankton were identified. The dominant species of zooplankton were
Filinia longiseta and Keratella cochlearis var. hispida in
late May in 1955 and K. cochlearis var. hispida and Bosmina
longirostris in the late July of 1955 and in the middle September of 1956.
The majority of phytoplankton was Anabaena spp. in the late July of 1955,
Melosira italica var. tenuissima in late May and Asterionella
formosa in middle September in 1956.
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-
Sci. Rep. Hokkaido Fish Hatchery
(13), 1959
- 13-1
Age
determination of chum salmon in the Northern Pacific Ocean during the early
parts of fishing season. Kobayashi, T. pp. 1-10. (In Japanese with English
summary)(1,810KB)
Abstract
To establish the age determination
of high-seas chum salmon, the scale pattern was examined for chum salmon
captured in the North Pacific Ocean from May to early June, 1956. Many
individuals commenced no new growth of the year, forming resting zone in the
margin of scale. A few individuals showed the new growth of the year, which was
formed by 1-4 circuli outside the resting zone. The number of circuli in the
last growth zone as well as the number of resting zone and width of circuli in
the last growth zone should be taken into account for determining the age of
chum salmon in the North Pacific Ocean during May and early June.
- 13-2
Some
knowledges on the growth and conditions of gonad of pink salmon in the North
Pacific Ocean. Okubo, S. pp. 11-22. (In Japanese)(520KB)
Abstract
The author examined the growth and
gonad somatic index (GSI) of pink salmon captured in the North Pacific Ocean and
Bering Sea off Kamchatka Peninsula from May to July in 1957. During this period,
the fork length and body weight increased 7 cm and 600 g, respectively, and GSI
of males and females became 15 and 3 times, respectively.
- 13-3
Estimation and its accuracy of the number of eggs and fry of chum salmon in
artificial hatching. Sakano, E. pp. 23-27. (In Japanese with English
summary)(303KB)
Abstract
A sampling method was applied for
estimating number of eggs and fry of chum salmon produced at hatcheries. The
number of eggs was estimated using a tray for the sampling unit. The number of
fry was obtained by counting fry per weight in kg. The accuracy of these
estimations was evaluated by comparing actual number counted individually.
- 13-4
A
preliminary report on the relation of blastoderm and vacuoles secreting ketoenol
substance in the course of salmon development. Nishida, H. pp. 29-34. (In
Japanese with English summary)(4,508KB)
Abstract
This is a preliminary report on
the morphological character of the blastoderm and vacuoles secreting ketoenol
substance during the early development of chum salmon eggs. The vacuoles
secreting ketoenol substance are found on/in the cortical layer of eggs.
Numerous granule materials are found in the perivitelline space of blastoderm
periphery. Such materials are considered to be secreted from the vacuoles. The
surface of the blastomere is irregular in shape and indistinctly outlined at
some parts where it adheres to the granules materials existed in the
perivitelline space. Among the blastomeres of the blastoderm, considerable
number of amoeboid cells are also recognized. In conclusion, it is considered
that the blastoderm is in close relation with whole egg substance not only
internally in it self but also externally at its surface.
- 13-5
Studies on the kokanee salmon in Lake Towada, northern Honshu, Japan (1).
Tokui, T. pp. 32-44. (In Japanese with English summary)(549KB)
Abstract
In Lake Towada, northern Honshu, "himemasu"
(=lacustrine sockeye salmon) population was established by several egg
transplants. Population dynamics of "himemasu" in the lake was studied in
1950-57. A population-density-dependent effect was observed in the body size of
salmon. Records of transplant of "himemasu" in the northern Japan were
summarized in this paper.
- 13-6
A list
of fishes known to inhabit in Towada Lake, northern Honshu, Japan. Hikita,
T., and Taniguchi, S. pp. 45-48. (In Japanese with English summary)(279KB)
Abstract
In Lake Towada, 17 fish species
have been transplanted from many localities, the enhancement was unsuccessful
for 8 species: brook trout, whitefish, catfish, ayu, pond smelt, chum salmon,
whitespotted char, and Japanese dace. Nine fish species establishing in the lake
are as follows: lacustrine sockeye salmon ("himemasu"), masu salmon, rainbow
trout, charr (Salvelinus pluvius), carp, crucian carp, eel, freshwater
sculpin (Cottus pollax), and goby (Rhinogobius similis).
- 13-7
Marking experiments of young salmon in Hokkaido (IV). Results observed in 1957.
Sakano, E., and Miura, I. pp. 49-50. (In Japanese)(98KB)
Abstract
Many marked chum salmon adults
released as fry from the Tokoro River were recaptured within this river and the
coastal waters of Okhotsk Sea around the mouth of this river in 1957.
- 13-8
Seasonal changes of vertical distribution of zooplankton in Lake Shikotsu,
Hokkaido. Kurohagi, T., and Sasaki, S. pp. 51-55. (In Japanese with English
summary)(351KB)
Abstract
The vertical distribution of
zooplankton was observed by offshore vertical net hauling for each layer of Lake
Shikotsu in the daytime from March 1955 to August 1956. Daphnia longispina
var. hyalina was commonly distributed in the depth of 0-50 m during
June-December, and of 20-100 m in March and April, and its maximum abundance
appeared in the layer of 10-30 m through June, August and October, 20-40 m in
December and March, and about 50 m in March and April. Bosmina longirostris
was distributed in the layer of 10-40 m, and the abundant population was found
in the layer of 10-20 m in August. Scapholeberis mucronata,
Acanthodiaptomus pacificus and copepod nauplii were distributed in the layer
of 0-10 m or 10-20 m in the spring and summer. The maximum distribution of
Synchaeta oblonga (rotifer) was found in the layer of 30-50 min March,
10-20m in April, and 40-60 m in June and August.
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Sci. Rep. Hokkaido Fish Hatchery
(12), 1958
-
12-1
Natural propagation of chum salmon, Oncorhynchus keta in
Memu River, Tokachi. Sano, S., and Nagasawa, A. pp. 1-19.
(In Japanese with English summary)(3,267KB)
Abstract
Natural spawning of chum salmon
was observed in the Memu River, a branch of Tokachi River. The
Memu River had about 0.2-0.3 m depth and its water temperature
ranged from 7°C to 9°C. The water temperature in spawning redds
showed about 1°C higher than that of river water. The peak in
the number of spawners was in late October. The age composition
of spawners varied among the observed 3 years (1954-56). The
fecundity of adults was 2,704 in average and increased with fish
age. Female chum salmon deposited eggs into 2 or 3 nests with
same male. A female took 1-2 hours to make a nest.
- 12-2
An ecological study on the salmon fry, Oncorhynchus keta
(5). The behaviour of chum salmon fry to their seaward
migration. Kobayashi, T. pp. 21-30. (In Japanese with
English summary)(615KB)
Abstract
The seaward migration behavior of
chum salmon fry was investigated in an aquarium at Chitose
Hatchery, and in the Chitose River. Chum salmon fry migrated
seaward most frequently during night. Muddy water facilitated
their downstream migration. Changes in water temperature, water
level, and dissolved oxygen scarcely affected their seaward
migration.
- 12-3
On the structure of the periblast of Oncorhynchus keta (Walbaum).
Nishida, H. pp. 31-36. (In Japanese with English summary)(1,557KB)
Abstract
The purpose of this communication
was to show the periblast structure in chum salmon embryo. The
structure of basic protoplasm was granular and fibrous. The yolk
globules had complex nature with ketoenol substances and
ketoenol lipoides. The vacuoles secreting ketoenol substance
were noticed. The common and the small nucleus-like bodies were
observed as well as the nuclei of periblast. The pigment
granules, ketoenol substance granules and ketoenol-lipoid
substance granules were noticed.
- 12-4
The periblast nucleus in the dog-salmon embryo, Oncorhynchus
keta (Walbaum). Nishida, H. pp. 37-44. (In Japanese with English
summary)(2,052KB)
Abstract
The present paper described the
morphological character of the periblast nucleus of chum salmon
embryo. The nuclei contained in the periblast were spherical,
rounds, oblong and lobed. The largest nuclei were found to be
100 µm in length. Various intermediate nuclei were detected. The
existence of the nuclear membrane was indistinct, and no
evidence of a nuclear membrane could be observed in a great
number of periblast nuclei. The large and the small nucleus-like
bodies were observed as well as the nucleus of periblast. The
complete absence of mitotic figures was noticed.
- 12-5
Occurrence of the mottled dog-salmon, Oncorhynchus keta (Walbaum).
Hikita, T. pp. 45-49. (In Japanese with English summary)(218KB)
Abstract
This paper reported an aberrant
form of chum salmon characterized by unusual body color. The
fish was collected in the Teshio River in October, 1956. The
external appearance was remarkable by a great number of motley
and blotches. The specimen showed the ground coloration with
blackish or darkish black in the head, dorsal, adipose and
caudal fins, and with yellowish white in the whole body . The
distribution of the motley character did not exhibit a
symmetrical arrangement on the body surface. In addition, albino
chum fry were sometimes found in Teshio Hatchery in early spring
every years. The occurrence of the mottled chum salmon and
albino fry may be due to mutation.
- 12-6
Chum salmon tagging experiments in spawning streams of Hokkaido.
Nishino, K. pp. 51-61. (In Japanese with English summary)(540KB)
Abstract
A series of adult chum salmon
tagging experiments was planned to collect all possible data in
relation to the upstream migration behavior in rivers. Tagged
chum salmon were released from six points in four rivers. The
percentage of recoveries extremely varied among years in the
same stream. The highest average recovery was 27.1% for adults
released at Juyonsen of the Nishibetsu River, and the lowest was
20.7 % at Tabikorai of the Tokachi River. The average migration
distance was 1.9-4.2 km per day. Among five kind of tags used in
this study, harpoon-type tag showed the best result for adult
salmon tagging.
- 12-7
Marking experiments of young salmon in Hokkaido (III).
Results observed in 1956. Sakano, E., and Miura, I. pp. 63-96.
(In Japanese)(1,319KB)
Abstract
Records of recapture of marked
chum salmon fry in 1956 were summarized in this paper. Many
adults of marked chum salmon originating from the Tokoro River
were recaptured within this river and the coastal waters of
Okhotsk Sea near the river in 1956.
- 12-8
Studies on the annual succession of the plankton organisms in
Lake Shikotsu, Hokkaido (I) (quantitative succession of the
plankton organisms at an offshore station of Lake Shikotsu, May
1952-June 1957). Kurohagi, T. pp. 97-110. (In Japanese with
English summary)(805KB)
Abstract
Seasonal changes in abundance of
plankton organisms were examined in Lake Shikotsu from May 1952
to June 1957. This large and deep caldera lake was enriched by
adding commercial inorganic fertilizers (super phosphate, 750kg;
ammonium sulphate, 3,750kg) in May-July, 1953. Zooplankton
organisms were very poor in 1952-53 (Bosmina longirostris
was dominant), but became abundant in 1954-1956 (Daphnia
longispina and Synchaeta oblonga were dominant).
Phytoplankton organisms were very poor in 1952-53, but increased
since 1954. they became most abundant in 1956, but slightly
decreased in 1957 (Melosira italica was dominant).
- 12-9
On the hermaphroditic gonads of the blueback salmon (O. nerka)
and the chum salmon (O. keta). Hikita, T. pp.
111-114. (In Japanese with English summary)(290KB)
Abstract
The author examined externally the
hermaphroditic gonads of a chum salmon collected from the
Chitose River, and a sockeye salmon occasionally captured in the
high seas of the North Pacific Ocean. The Chitose specimen
showed the aberrant gonad which were consisted of the ovarian
part in anterior and the testicular part in posterior. The
specimen from the North Pacific Ocean had the gynandmorphic
gonad which was mosaic of the ovarian and testicular parts. The
author compared the above samples with several specimens with
abnormal gonads formerly recorded from northern Kuril Islands
and Hokkaido.
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Sci. Rep. Hokkaido Fish Hatchery
(11), 1956
- 11-1
An ecological study on the salmon fry, Oncorhynchus keta
(4). Some observations on the chum salmon fry entered into an
irrigation canal. Kobayashi, T., Ozaki, Y., and Ito, Y. pp. 1-5. (In
Japanese with English summary)(325KB)
Abstract
In the Chitose River, chum salmon
fry often strayed into an irrigation canal during their seaward
migration. The occurrence of straying fish was more frequent at
night than in daytime. The peak was in late May. These fry
resided in the canal for a few months, and disappeared by middle
July. The rate of straying fish among hatchery-released fry was
estimated trifling.
- 11-2
On the viability of the sperm and the egg left in the dead body
of dog-salmon, Oncorhynchus keta (Walbaum). Okada, S.,
Ishikawa, Y., and Kimura, G. pp. 7-17. (In Japanese with English
summary)(596KB)
Abstract
The viability of sperm and eggs in
dead adult chum salmon was affected by temperature. The
fertilizational ability of sperm and egg maintained for about 90
minutes and 8 hours at 11-12°C, 50 minutes and 5 hours at
13-14°C, and 30 minutes and 4.5 hours at 18-19°C, respectively.
The sperm lost its fertilizational ability faster than the eggs
in dead salmon, because the sperm consumed much oxygen as
compared with the eggs.
- 11-3
The effect of the control of light upon the rate of
smoltification and the growth of body of juvenile masu salmon.
Kubo, T. pp. 19-23. (In Japanese with English summary)(261KB)
Abstract
The author examined effects of
light control on the rate of smoltification and growth in
juvenile masu salmon. The total body length was largest in the
lighting group, middle in the control group, and smallest in the
shaded group. The rate of smoltification was highest in the
control group, middle in the lighting group, and least in the
shaded group. These results suggest that the continued light
treatment might affect the growth and maturation of parr in the
autumn of the first year of life, and might control the thyroid
function to prevent the smoltification. The shaded treatment
might be disadvantageous for the growth of parr.
- 11-4
Pacific salmon (genus: Oncorhynchus) known to occur in
coasts and rivers within Hokkaido. Hikita, H. pp. 25-44. (In
Japanese with English summary)(2,335KB)
Abstract
Six species of Pacific salmon (chinook
salmon, chum salmon, pink salmon, coho salmon, sockeye salmon,
and masu salmon) captured in Hokkaido were described from the
view point of morphology, geographical distribution, and
fishery. A reference table for the species identification was
also prepared in this paper.
- 11-5
Marking experiments of young salmon in Hokkaido (II). Results
recaptured in 1955. Sakano, E. pp. 45-47. (In Japanese)(543KB)
Abstract
Chum and pink salmon fry were
released from various hatcheries after marked by fin-clips in
1951-1954. However, the released sites could not be specified
for most case of recaptured fish. In addition, the recovery rate
was low for marked pink salmon.
- 11-6
Bacteriological
investigations on the death in groups of salmon fry (I).
Observation on the Bacillus isolated from dead salmon fry.
Nishino, K., and Ozaki, Y. pp. 59-64. (In Japanese with English
summary)(368KB)
Abstract
The authors examined an epizootic
disease of chum salmon fry reared at Makubetsu Hatchery along
the Tokachi River System in 1955 and 1956. The mortality was 40
% and 15 % in 1955 and 1956, respectively. Some strains of
bacteria were isolated from the diseased fish, but they could
not be identified nor reveal any pathogenicity to salmon fry. It
could not be determined whether the disease was caused by
bacteria or not.
- 11-7
On the anatomy and development of carp in Hokkaido. Hikita, T.
pp.
65-95. (In Japanese)(1,780KB)
Abstract
Anatomical view and early
development of carp including egg and fry stages were described
in the paper.
- 11-8
Effect on the tolerance of carp egg and fry in some 24-D
solutions. Eguchi, H., and Kai, T. pp. 97-100. (In Japanese)(173KB)
Abstract
The toxicity of an agricultural
chemical, 24-D against carp fry and eggs was evaluated. The
threshold of 24-D concentration was 600 ppm for fry. In the case
of eggs, however, the normal concentration (36 ppm) of 24-D was
harmful.
- 11-9
Some experiments on malachite green. Takayasu, M. pp. 101-108. (In
Japanese with English summary)(499KB)
Abstract
The author presented some data of
bioassay to detect the effect of malachite green on fishes. The
lethal concentration for chum salmon and goldfish was
1/800,000-1/1,000,000 within 24 hours, and 1/500,000 -1/600,000
within 5-15 hours. To reduce the toxicity of malachite green, an
addition of small amount of sodium sulfate solution to the waste
fungicide solution showed the best efficiency. An addition of
24-15 cc of 8% sodium sulfate (anhydrous) to 180 litter of the
waste solution was mostly efficient to neutralize the toxicity
of malachite green.
- 11-10
On the standalization of water used as fish-cultural water
(general consideration). Takayasu, M., and Eguchi, H. pp. 109-112.
(In Japanese)(159KB)
Abstract
The Fisheries Agency of Japan has
proposed the standard of water quality in order to control
factory waste water and sewage in 1955. In Hokkaido, however,
many factories are not able to obey the regulation.
- 11-11
The comparative investigation in relation to the estimated fish
crop and productivity of fishing interest in Lake Akan. Eguchi,
H., and Osanai, M. pp. 113-118. (In Japanese)(423KB)
Abstract
Lake Akan was assessed as
mesotrophic lake from its water quality, fauna of benthic
animals, zooplankton, and fish communities. The carrying
capacity of fish populations in Lake Akan was estimated.
- 11-12
The seasonal
observation in some feeding plankton crustacea of pond-smelt,
Hypomesus olidus (Pallas) in Lake Akan. Osanai, M. pp. 119-128.
(In Japanese)(483KB)
Abstract
In Lake Akan, Japanese smelt (Hypomesus
nipponensis) fed mainly on copepods (Mesocyclops hyalinus,
nauplii), cladocerans (Daphnia sp., Bosmina
coregoni) and midge larvae. Seasonal changes of these
organisms in the lake were also described. The smelt stomach
contents rarely reflected the plankton fauna in the lake water.
- 11-13
The chemical contents of Lake Chimikeppu. Yoshizumi, K., and
Fumoto, R. pp. 129-134. (In Japanese)(687KB)
Abstract
Water quality was surveyed in Lake
Chimikeppu in Abashiri Country in May and September, 1956. The
water temperature had no horizontal differences in the lake
surface, but lowest in deep water of northern area. The pH
showed vertical variation due to abundant phytoplankton in the
surface water. The sodium phosphate was abundant in the deeper
water, and the concentration increased in September.
- 11-14
A limnological survey of Takadomari Reservoir. Kurohagi, T.
pp.
135-153. (In Japanese)(1,222KB)
Abstract
In 1955-56 limnological surveys
were conducted in the Takadomari Reservoir that was produced by
the construction of dam in the upstream of the Uryu River in
1953. The survey included water temperature, pH, dissolved
oxygen, transparency, and plankton fauna.
- 11-15
List of marine and fresh-water fishes and aquatic animals found
in some streams and their mouth's vicinities in Hokkaido.
Hikita, H. pp. 155-170. (In Japanese with English summary)(818KB)
Abstract
This report was a brief survey of
freshwater and marine fishes in Hokkaido from 1950 to1954. Among
86 species of fishes and aquatic animals, 77 species were
freshwater and marine fishes. Fishes could be divided into 4
types by their habitats: freshwater, brackish, marine, and
anadromous fishes. The author found two forms in Japanese dace (Tribolodon
hakonensis) and whitespotted charr (Salvelinus
leucomaenis), such as land-locked and sea-run forms of masu
and sockeye salmon. Some freshwater fishes found in Hokkaido
were more widespread to northern areas such as Sakhalin,
Kamchatka, Maritime Province of Russia, and Alaska. Common fish
species lived on almost every rivers, showing no particular
differences in the fish fauna with except for some specific
rivers in Hokkaido.
- 11-16
On the computation of body-length composition, length-weight
relationship and egg-number of a flounder (Limanda schrenki
Schmidt) in lake Notoro, Hokkaido. Minagawa, H. pp. 171-180. (In
Japanese)(419KB)
Abstract
Cresthead flounder (Pleuronectes
schrenki) (n=3,012) captured in Lake Notoro, eastern
Hokkaido, were examined for their body size and fecundity. The
mean fecundity was 579,000 in adult females whose body weight
was 200-600 g.
- 11-17
Some observations on the natural spawning of the spring herrings
along the western coast of Hokkaido IV. The observation on the
fishing condition and the spawning condition of spring herring
in 1956. Ohigashi, S., and Uchiyama, M. pp. 181-202. (In Japanese
with English summary)(1,837KB)
Abstract
The spawning and abundance of
spring Pacific herring (Clupea pallasii) were observed in
1956 along the western coast of Hokkaido. The catch of herrings
in 1956 was least abundant since 1938. The herrings which
spawned in shallow waters were very scarce, spawning areas
having extended only about 8 km along the coast. The catch by
set net was less in amount than that by gill net. In the
northern fishing ground, herring spawners were caught by gill
nets at the depth of 90-120 m, suggesting that their spawning
might occur in offshore deep waters.
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