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Vol.01-10
No.11-20
No.21-30
No.31-40
No.41-50
Vol.01(1)
Vol.02(1) Vol.03(1)
Vol.03(2) Vol.04(1)
Vol.04(2)
Vol.05(1) Vol.05(2)
Vol.06(1,2)
Vol.07(1,2) Vol.08(1,2)
Vol.09(1,2) Vol.10(1,2)
-
Sci. Rep. Hokkaido Fish Hatchery
10
(1,2), 1955
- 10-1
Observations on the natural spawning of the salmon,
Oncorhynchus keta. Conditions of the spawning bed. Sano, S.
pp.
1-6. (In Japanese with English summary)
 (393KB)
Abstract
Environmental characters of chum
salmon spawning redds were examined in 4 rivers of Hokkaido. The
gravel composition of redds was dominated in gravels of 5-30 mm
in diameter. The flow rate and depth in redds were 0.2 m/sec and
0.15 m, respectively. The water temperature ranged from 4° to
11.5°C, being higher than that of river water in winter.
- 10-2
Some observations on the eggs of the mature salmon (Oncorhynchus
keta) in Hokkaido, with special reference to the race of
salmon as characterized by the size of their eggs. Watanabe, M.
pp.
7-20. (In Japanese with English summary)(768KB)
Abstract
The purpose of present study was
to compare egg size and fecundity of chum salmon among nine
river populations in Hokkaido. The fecundity of chum salmon
generally increased in proportion to the fish body size. The
number of eggs per unit body weight was generally greater in
small fish, and it decreased proportionally in larger ones. The
size of eggs generally increased in proportion to the body
length. Comparing egg size of chum salmon from nine rivers in
Hokkaido, it was largest in the Tokachi River population, and
smallest in the Chitose River population. The results indicated
that these two populations were apparently independent each
other.
- 10-3
On the activity and fertilizing capacity of sperm in dog-salmon
(Oncorhynchus keta). Okada, S., and Ito, T.
pp. 21-31.
(In Japanese with English summary)(786KB)
Abstract
Sperm of chum salmon had a tail 10
times longer than head, and showed about 36 µm in total length.
The external preservable period of sperm activity (EPS) was
changed with temperature: 4 hours at 33°C, and about 7 days at
5°C. A relationship between EPS (Y) and temperature (X) was
represented as the following formula: X (Y+1.1) = 45. Under
air-interception, the sperm activity was lost within 60 minutes
at 20°C, after 60 minutes at 11°C, and 180 minutes at 0°C.
- 10-4
A consideration on the method of measuring the scale size of the
salmon (O. keta). Kobayashi, T. pp. 33-41. (In Japanese with
English summary)(507KB)
Abstract
The author examined the scales of
chum salmon captured in the mouth of the Ishikari River in order
to find out an appropriate method of scale measurement. The
scale radius should be measured along the line through the
center of the scale and the middle point between the both
outside margins of last resting zone on the juncture of the
exposed and covered portions of the scale. The size and growth
ratio of the scale varied significantly among its sites on the
body. The estimated body length also varied with body sites
where the scale was sampled. The sampling site and measurement
of scales must be unified for the individual growth estimation
and stock identification.
- 10-5
Morphological an histochemical studies on the blood cells
finding in the yolk of salmon embryo. Nishida, H. pp. 43-52. (In
Japanese with English summary)(2,456KB)
Abstract
A histochemical observation
revealed the presence of abundant blood cells in the yolk of
embryo of chum salmon. Blood cells were distributed adjacent to
the oil drops. The nature of these blood cells was examined
applying Lisbon's benzidine reaction to peroxidase technique.
This technique showed that the blood cells were indicated by
absence of cell division and presence of cytoplasm fused into
yolk. The cytoplasm was positive to the peroxidase reaction as
same as the nucleus, but negative to methyl green.
- 10-6
Marking experiments of young salmon in Hokkaido (1). Results
recaptured in 1954. Sakano, E., and Hara, S. pp. 53-61. (In
Japanese)(345KB)
Abstract
Adult recapture records of marked
chum salmon fry released in the Chitose River, Tokoro River, and
Shiriuchi River were summarized in this paper. Many marked chum
salmon released in the Tokoro River were recaptured as adult
within this river and the coastal waters around the mouth of the
river in 1954.
- 10-7
On an aberrant form of chum salmon taken from the northern
Pacific Ocean and some examples of salmonoid fishes in Hokkaido.
Hikita, H. pp. 63-71. (In Japanese with English summary)(766KB)
Abstract
The author described a chum salmon
with abnormal head, which was caught in the North Pacific Ocean
in the summer of 1954. In addition, other deformities were
recorded for chum salmon from the Yurrapu River, masu salmon and
whitespotted charr (Salvelinus leucomaenis) from the
Teshio River.
- 10-8
On the recording equipment taking a count of salmon-numbers by
the utilization of photoelectric cell (preliminary note).
Suetake, T. pp. 73-81. (In Japanese)(922KB)
Abstract
The author developed an automatic
counting machine to detect adult salmon migrating in rivers.
This device needed more improvements for the accurate records.
- 10-9
A consideration on the
frequency of length, weight, condition factor and on the secular
variation of kokanee salmon (Oncorhynchus nerka) in Lake
Shikotsu, (1899-1955). Mihara, T., and Eguchi, H. pp. 83-104. (In
Japanese)(893KB)
Abstract
Long-term changes in the body
length, body weight, and condition factor of Lake Shikotsu "kokanee
salmon" (=lacustrine sockeye salmon) were monitored from 1899 to
1955. The body size was largest in 1899, 1927, 1939 and 1955,
and smallest in 1924-25 and 1953. The reduced body size might be
caused by lack of food organisms in the lake. Thus lake
fertilizations were conducted in 1927 and 1953. These
fertilizations improved the body size of lacustrine sockeye
salmon.
- 10-10
A study on the use of pine-tree for carp-nests. Eguchi, H., and
Oya, Y. pp. 105-107. (In Japanese)(156KB)
Abstract
Carbon dioxide assimilation of
pine tree (Abies sachalinensis), which was prepared for
spawning nest of carp, affected dissolved oxygen and pH in
water.
- 10-11
The effect of the disinfection of malachite green upon the carp
egg. Oya, Y. pp. 109-114. (In Japanese)(332KB)
Abstract
Toxic effects of malachite green
and rapid change of water temperature on carp eggs were studied.
The results revealed that malachite green solution at the
concentration of 1.7-5 ppm could prevent fungus infections on
carp eggs. These concentrations were used as usual treatment in
hatcheries. Five ppm of malachite green solution showed toxic
effect on carp fry, but there was no mortality in 3.3 ppm for 1
hour treatment. A change of water temperature over 15.2°C had no
effects on the hatching rate of carp eggs.
- 10-12
Some observations on the natural spawning of the spring herrings
along the western coast of Hokkaido III. Fishing condition of
spring herring in 1955 and underwater observations on the
natural spawning ground of the herring at Tomamai. Tamura, T.,
Ohigashi, S., and Hirobe, T. pp. 115-131. (In Japanese with English
summary)(1,212KB)
Abstract
Pacific herring catch was very
poor on the Japan Sea coast of Hokkaido in the spring of 1955.
Natural spawning ground of herring has gradually reduced in
Hokkaido. The number of the herring eggs from the natural
spawning ground was 222,100-4,287,160 m2. Herring fry
were rarely found in 1955.
- 10-13
On the egg distribution of Alaska pollack (Theragra
chalcogramma) observed in Funka (Uchiura) Bay, 1954 -II.
Ito, K., Fujita, T., Hayashi, S., and Yasukawa, M. pp. 133-144. (In
Japanese)(643KB)
Abstract
In the Funka Bay, the egg
distribution of walleye (Alaska) pollack (Theragra
chalcogramma) was examined with ocean conditions in the
winter of 1954. The spawning grounds were distributed in waters
whose depth was 50-75 m off Yakumo, Mori and Sunahara coasts. A
peak of spawning season was estimated to be from January to late
February. The estimated total eggs spawned in 1954 was 13.7
billions.
- 10-14 On
the egg distribution of Alaska pollack (Theragra chalcogramma)
observed in Funka (Uchiura) Bay, 1955 -III. Ito, K., and
Kurahashi, S. pp. 145-159. (In Japanese)(700KB)
Abstract
The spatial distribution of
walleye pollack eggs was determined in Funka Bay, southern
Hokkaido in 1953-1955. Pollack eggs were most abundant in water
off Sunahara every year. Their main spawning season was
estimated between late January and early February. More than ten
billion eggs were produced in the bay, but most of them died due
to environmental factors.
- 10-15
On the Alaska pollack juvenile (Theragra chalcogramma)
taken from the Funka Bay. Ohigashi, S., and Ito, K. pp. 161-167. (In
Japanese)(582KB)
Abstract
The authors examined the body size
and scale of juvenile walleye pollack collected in the Funka Bay
in the spring of 1954-1955. The first scale formation occurred
when the body length became more than 36 mm. Circuli were found
in the fish whose body length was 42-51 mm.
- 10-16
Limnological studies on the lakes of Kunasiri Island. Takayasu,
M., Kondo, K., Ohigashi, S., and Kuroda, K. pp. 169-216. (In
Japanese with English summary)(3,167KB)
Abstract
This report is the results of the
investigations carried on 6 lakes on Kunashiri Island during the
summer of 1934 and 1935. Investigations included morphological
survey of lakes, physical and chemical observations, and
biological investigations. The authors deduced the fish
productivity of these lakes from limnological observation, and
proposed several plan for fish culture in these lakes.
- 10-17
Limnological study of Lake Mashu. Conditions on June, 1954.
Kurohagi, T., Yoshizumi, K., and Kai, T. pp. 217-230. (In Japanese)(965KB)
Abstract
Lake Mashu may have most clear
water in the world. The water in this lake was transparent to a
depth of 41.6 m in 1931. The authors reported about water
quality, and fauna and abundance of phytoplankton and
zooplankton in the lake in June 1954.
- 10-18
A consideration on the chemical contents in the Ishikari River
(Asahigawa to Ebetsu) observed from fish-cultural water
(measurement of bio-chemical oxygen demand: B.O.D.). Eguchi, H.,
and Yoshizumi, K. pp. 231-237. (In Japanese with English summary)(470KB)
Abstract
On March 30-31, 1955, the authors
investigated the chemical contents of water (biochemical oxygen
demand; BOD) in 10 stations of the Ushubetsu River (Asahikawa)
and Ishikari River (from Asahikawa to Ebetsu). The consumption
of 5 days BOD ranged from 0.9 ppm to 120 ppm. More than 5ppm of
BOD consumption was recorded in the Ushubetsu and Ishikari
Rivers. Apparently these water was polluted by waste waters from
industries located along the Ushubetsu River.
- 10-19
The seasonal observations on the chemical contents of the
Ishikari River. Yoshizumi, K. pp. 239-257. (In Japanese)(988KB)
Abstract
The author surveyed water quality
in the Ishikari River System in 1953-55. In the upper region, it
was clean without apparent seasonal change in water quality.
However, the water was polluted when the river run through
Asahikawa City. The water pollution might be attributable to
waste water from pulp mill industries along the Ushubetsu River,
a branch of the Ishikari River in the city.
- 10-20
On the influence of several chemical compounds upon fishes (II).
Takayasu, M. pp. 259-280. (In Japanese with English summary)(1,050KB)
Abstract
Influences of several constituents
of industrial waste water on fishes were examined in order to
estimate the impact of industrial sewage on fishery. The results
contained the minimum harmful doses of 44 chemicals and some
industrial waste water.
 Back
to top
-
Sci. Rep. Hokkaido Fish Hatchery
9
(1,2), 1954
- 9-1
Limnological studies on the lakes of Etorup Island. Takayasu,
M., Kondo, K., Ohigashi, S., and Watari, S. pp. 1-85. (In Japanese
with English summary)(4,399KB)
Abstract
This report is the results of
investigations in 13 lakes on Iturup Island during the summer
season of 1933 and 1934. Investigations included morphological
survey of lakes, physical and chemical observations, and
biological investigations. The authors deduced the fish
productivity of these lakes from the data of limnological
observations, and mentioned a plan of fish culture there.
Anadromous sockeye salmon was recorded in five lakes including
Lake Urumobetsu.
- 9-2
The death from suffocation in the developing eggs of dog-salmon,
Oncorhynchus keta (Walbaum). Okada, S. pp. 87-94. (In
Japanese with English summary)(789KB)
Abstract
Chum salmon eggs, 30 minutes after
fertilization, were kept at low oxygen concentration (0.3 cc/ml)
for 3 days, and then reared in running water. The blastodiscs of
eggs showed a tendency of degenerating 4 days after
fertilization. After about one week, the blastodiscs continued
to disintegrate gradually. Most eggs, nevertheless, maintained
normal translucent appearance and did not turn white or opaque
for more than 4 weeks. These observations suggest that the
translucent condition of dead eggs may be maintained by such
mechanism as in the case of unfertilized eggs.
- 9-3
Some observations on the
natural spawning of the spring herring in the western coast of
Hokkaido-II. Observations made by diving into water on the
natural spawning ground of the herrings. Tamura, T., Okubo, S.,
Fujita, T., and Hirobe, T. pp. 95-112. (In Japanese with English
summary)(1,043KB)
Abstract
The breeding behavior of Pacific
herring (Clupea pallasii) was surveyed by diving
observation in the coast of Mashike, Rumoi and Onishika along
the Japan Sea coast of Hokkaido in the spawning season of
1953-54. The natural spawning grounds were observed on seaweed
or rocks in shallow water, where the sperm water (milky water)
occurred. The maximum number of herring eggs (per square meter)
from the natural spawning ground was calculated 1,540,000 at
Afun, 5,800,000 at Obira, and 1,530,000 at Onishika. The
fertilization rate of herrings eggs from the natural spawning
ground was 72-98%, and the hatching rate of the eggs was 95-98%.
Recently, the natural spawning ground of herring seemed to be
gradually reducing.
- 9-4
The affinity of the spawning type of salmon (Oncorhynchus
keta Walbaum) which are found in the rivers of Hokkaido.
Oya, Y. pp. 113-125. (In Japanese)(1,412KB)
Abstract
The timing of river run was
examined for chum salmon returning to rivers of Hokkaido using
records of adult catches in rivers. The peak of river runs was
found in October in most rivers. The beginning of river run
tended to be earlier in large rivers than in small rivers. The
timing of adult return was similar among neighboring river
stocks.
- 9-5
On the change of shape in the blastodisc of the unfertilized egg
of dog-salmon, Oncorhynchus keta (Walbaum) activated by
water. Okada, S. pp. 127-132. (In Japanese with English summary)(1,028KB)
Abstract
When activated with water, the
blastodisc of unfertilized eggs of chum salmon performed a
certain change of shape, that was entirely similar in appearance
that of fertilized eggs until near the end of blastula stage.
Before immersing into water, the blastodiscs of unfertilized
eggs spread thinly and widely over the animal pole of eggs. When
fertilized or activated with water, the blastodisc began to
condense gradually. In the fertilized eggs, the first cleavage
appeared after about 9 hours (water temperature 9-12°C), but
until this stage the eggs were hardly distinguished from the
unfertilized ones. In fertilized eggs, the cleavage was going on
and the blastodisc was rising from the yolk gradually until it
reached to the blastula stage with typical round shape at about
42 hours after fertilization. Naturally the cleavage did not
occur in the blastodisc of the unfertilized eggs, though
entirely similar change of shape of the blastodisc appeared side
by side with the fertilized ones.
- 9-6
Investigations on the number of salmon fry produced by means of
artificial hatching I. The loss of salmon eggs. II. Estimation
of number of salmon eggs adopted. Sakano, E. pp. 133-136. (In
Japanese with English summary)(263KB)
Abstract
The survival rate of chum salmon
eggs kept in artificial incubator was examined from the
fertilization to the eyed egg stage. The mortality rate was 0.8%
from the fertilization to the deposition into incubators, and
0.6% from the deposition to the eyed egg stage. A number of eggs
in a incubator estimated by the usual method was 1.6% less than
the actual number.
- 9-7
On the common names of the salmonid fishes and their related
forms found in northern Japan and its adjacent waters. Hikita,T.
pp.
137-145. (In Japanese with English summary)(453KB)
Abstract
The common, scientific, and local
names of salmonids and related fishes in northern Japan were
summarized in this paper.
- 9-8
Occurrence of remarkable glands in the oral cavity epidermis of
adult salmon, Oncorhynchus keta. Nishida, H. pp. 147-150. (In
Japanese with English summary)(219KB)
Abstract
The author made histological and
cytological observations on the newly found gland in the oral
cavity epidermis of adult chum salmon captured in the Ishikari
coast in October 1953. The gland was mainly distributed in the
epidermis of ventral side base of the gill arch. The gland was
clearly stained in metachromatical color with toluidin blue,
showing tubular or complex form.
- 9-9
A comparison between Hokkaido and South Kuril Islands on the
salmon egg-number. Eguchi, H., Hikita, T., and Nishida, H.
pp.
151-159. (In Japanese)(261KB)
Abstract
Body size and fecundity of adult
chum salmon were examined in Hokkaido (n=109), and Kunashiri and
Iturup Islands (n=134). The Average fecundity was significantly
higher in Hokkaido populations (2,586 eggs) than in South Kuril
ones (1,977 eggs). A correlation coefficient between the body
length and fecundity was also significantly higher in Hokkaido
populations (r = 0.547) than in South Kuril ones (r = 0.306).
- 9-10
The experimental fertilization of Lake Sikotsu (preliminary
report). Eguchi, H., Kurohagi, T., Yoshizumi, K., and Sasaki, S.
pp.
161-176. (In Japanese with English summary)(1,859KB)
Abstract
In Lake Shikotsu, superphosphate
(1,875 kg) and ammonium sulphate (375 kg) were introduced as
fertilizers from May 29 to July 18, 1953. Seasonal changes in P2O5
and NH3-N contents and plankton fauna were monitored
after the lake fertilization. Melosira italica began to
increase its abundance since December 1953. In the next summer,
abundance of Bosmina coregoni and Daphnia longispina
increased, and Acanthodiaptomus pacificus also appeared.
- 9-11
On the Herring found in Akkeshi Bay (2). Sakano, E. pp. 177-182. (In
Japanese with English summary)(361KB)
Abstract
Following the previous report
(7-10), the author observed the age composition and growth of
spring Pacific herring (Clupea pallasii) caught in
Akkeshi Bay near Kushiro from 1952 to 1954. Three- and four-year
age groups were always most abundant during the past three
years. The growth rate of herring coincided with that of
Hokkaido spring herring. The average value of the head length
index (the ratio of head length to body length) of four-year
group was always smaller than that of three-year group. However,
respectable variations of the index were found among sampling
years. Generally the index decreased with the increase of body
length. The mean value of the head length index was in
accordance with that of Akkeshi-numa-nishin (lake herring). As
for the mean of vertebral number, no significant difference was
observed between the three- and four- year groups collected in
the same year, but there was a significant difference among
sampling years.
- 9-12
Studies on the age and growth of rainbow trout (Salmo irideus
Gibbons) in Lake Mashyu. Kai, T. pp. 183-193. (In Japanese with
English summary)(943KB)
Abstract
Growth composition of rainbow
trout (Oncorhynchus mykiss) in Lake Mashu was examined by
scale analysis. A positive lineal relationship between the body
length and scale radius was observed. The scale analysis showed
that annual ring (resting zone) was expressed as age character.
The estimated body size by scale analysis was coincided with the
actual one.
- 9-13
Adult coho salmon captured in the Shokotsu River. Hikita, T.
pp.
195-198. (In Japanese)(321KB)
Abstract
A maturing coho salmon was
captured in the Shokotsu River along the Okhotsk Sea coast on
September 10, 1954. It was distinctive in having 14 dorsal fin
rays, 18 anal fin rays, 132 lateral-line scales, 13
branchiostegal rays, 21 or 22 gill rakers, and 54 pyloric caeca.
Back
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-
Sci. Rep. Hokkaido Fish Hatchery
8
(1,2), 1953
- 8-1
On the returning of pink salmon (Oncorhynchus gorbuscha
Walbaum) in Yurappu River. Sano, S., and Kobayashi, T. pp. 1-9. (In
Japanese with English summary)(615KB)
Abstract
In November 1951, about one
million eyed eggs of pink salmon in the Shibetsu River were
transplanted to the Yurappu River on the Pacific coast of
southern Hokkaido. The pink salmon fry were released after being
marked by removing adipose fin and left side of gill-cover. From
July 18 to September 27 in 1953, 27 marked fish were recaptured:
22 fish in the Yurappu River, one in the Yubetsu River, and four
in the Okhotsk Sea coast. The catch of pink salmon was estimated
about 4,500 fish in the coast near the Yurappu River. Thus, the
rate of adult returns might be about 0.5%.
- 8-2
A note on the fry of salmonid fishes rearing in the artificial
hatchery in Hokkaido, with special reference to the
discrimination of these salmon fry. Hikita, T. pp. 11-20. (In
Japanese with English summary)(497KB)
Abstract
The morphology of salmonid fry of
9 species (chum salmon, masu salmon, pink salmon, sockeye
salmon, rainbow trout, brook trout, Dolly Varden, and
whitespotted charr) was described. Especially, variations of
parr mark among species were noted.
- 8-3
Some observations on the natural spawning of the spring herring
in the western coast of Hokkaido. Tamura, T., and Okubo, S.
pp.
21-38. (In Japanese with English summary)(824KB)
Abstract
Pacific herring (Clupea
pallasii) annually migrated to spawn in the coast of western
Hokkaido in spring. In the present paper, the breeding behavior
of herring was observed around Rishiri Island in 1951 and 1952.
The mean fertilizing rate of herring eggs from the natural
spawning grounds was 96.5%. Herring eggs were found on seaweed
and small stones, being most abundant on kelps.
- 8-4
The cyto-histological observations on the gland cell of the
branchial epidermis with the comparison of two types of
Oncorhynchus masou, land-locked and sea-run form. Nishida,
H. pp. 33-38. (In Japanese with English summary)(366KB)
Abstract
There are two types in masu salmon
(Oncorhynchus masou): one is the landlocked form called "yamabe",
and the other is the sea-run form so called "masu". The sea-run
type smolt was called "ginke-yamabe" in Hokkaido. Yamabe and
ginke-yamabe reared in the pond of Chitose Fish Hatchery were
used to compare the structure of the gill epidermis. Acidophilic
large gland cells appeared in the branchial epidermis, and it
was abundant in the bases of the gills of ginke-yamabe. The
distinct inclusions of the acidophilic large gland cell were
mitochondria and Golgi materials. Function of the Golgi
materials in the cell was discussed in this paper.
- 8-5
Data on the studies of
the quality of land water in Hokkaido III. The quality of water
in the river which salmon ascends to spawning. Eguchi, H., and
Sindo, H. pp. 39-45. (In Japanese with English summary)(382KB)
Abstract
In 46 rivers where salmon ascended
to spawn, the authors investigated water quality including
hydrogen ion concentration, contents of silicate and oxygen
consumed as MnO4K, and ashes. The consumption of MnO4K
ranged from 1.8 to 85.0 mg/L, and was more than 10 mg/L in the
Ishikari River (Asahikawa), Okushibetsu, Kushiro, and Lake
Mokoto. Particularly it was 85.0 mg/L in the Ishikari River
water near Asahikawa, 29.8 mg/L in the Unabetsu River, 26.4 mg/L
in the Saromabetsu River, and 17.5 mg/L in the Okushibetsu
River. These waters were apparently polluted by waste waters
from industrial factories along the rivers.
- 8-6
Bacteriological study on disease of salmon and trout rearing for
maturity-I. Nishino, K. pp. 47-58. (In Japanese with English
summary)(692KB)
Abstract
A bacterial disease occurred among
adult chum, pink and masu salmon stocked in ponds during their
maturity. The disease was observed throughout Hokkaido with the
exception of southern parts of the region. A symptom of diseased
fish was similar to furunculosis, and six strains of bacteria
were isolated from the kidney. Judging from the morphological
and cultural characteristics of these organisms, the strains
might be different from Bacterium salmonicida (=Aeromonas
salmonicida), a causative agent of fish furunculosis.
Rainbow trout, masu salmon and chum salmon which were inoculated
with the isolated strains showed the same symptom as the
diseased fish and bacteria were isolated again from the kidney.
- 8-7
An experiment on the food mixed with aureomycine for the carp.
Eguchi, H., and Kai, T. pp. 59-62. (In Japanese with English
summary)(207KB)
Abstract
Carp were fed by diets mixed with
antibiotic aureomycin (0.1%) for 40 days. The carp growth was
well improved by adding the drug.
- 8-8
Histological and cytological studies on the hatch of salmon,
Oncorhynchus keta I. On the hatching gland, mucous cell, and
softening of egg membrane. Nishida, H. pp. 63-69. (In Japanese with
English summary)(343KB)
Abstract
Before hatching out, two types of
unicellular glands (hatching gland and mucous cell) were present
in the epidermis of chum salmon embryo. The development of these
glands started at the eyed stage. Many hatching gland appeared
in the oral cavity and gills two or three days before hatching,
but disappeared after that. The surface of embryo was covered
with mucous cells. Numerous secretary granules included in the
hatching gland, whose diameter reaching to 2 µm, were
mitochondria. This granule was well fixed with Bouin's solution,
and stained in blue with Mallory's triple stain. The mucous cell
inclusion was almost Golgi materials and by the use of basic dye
a distinct metachromatical color was produced. Toward the end of
the embryonic life, the egg membrane that consisted of three
layers, became highly softening. The change of constitution of
the egg membrane during the softening was studied by the use of
Mallory's triple stain.
- 8-9
An ecological study on the salmon fry, Oncorhynchus keta
(2). The migration and growth of the fry in the marking
experiment. Sano, S., and Kobayashi, T. pp. 71-79. (In Japanese with
English summary)(401KB)
Abstract
Marked juvenile chum salmon
(n=803,400) were released from the Chitose Hatchery in the
spring of 1953. They were recaptured in the Ishikari River and
on the Ishikari Coast (n=181). The results suggest that chum
salmon juveniles, released at mean body length (MBL) of 30.6 mm
from the hatchery between late April and middle May, immediately
migrated seaward, distributed along the Ishikari Coast, and
migrated offshore from Hamamasu and Rumoi coasts at the MBL of
62.0 mm in May and June.
- 8-10
An ecological study on the salmon fry, Oncorhynchus keta
(3). Observation on the descending of the salmon fry 1.
Kobayashi, T. pp. 81-85. (In Japanese with English summary)(230KB)
Abstract
Downstream migration of chum
salmon fry was observed in the experimental aquarium at Chitose
Salmon Hatchery. Their downstream migration became more
frequently in night than in day. Most of them, especially,
migrated within 2-3 hours after the sunset. The result suggests
that darkness may cause a downstream migration of salmon fry.
- 8-11
Comparative studies of relative growth and vertebral number for
Alaska pollack of Iwanai, Samani and Sahara, Hokkaido. Sakano,
E. pp. 87-94. (In Japanese with English summary)(305KB)
Abstract
Walleye (Alaska) pollack (Theragra
chalcogramma) were captured at Iwanai ( Japan Sea coast),
Samani ( Pacific coast), and Sahara (Pacific coast) in February,
1952. The difference of the coefficient of linear regressions
which was calculated for head length and other six dimensions on
body length was tested by F-test for a comparison of the
relative growth among populations. There was a considerable
significant difference in the coefficient of regressions between
Iwanai, and Samani or Sahara stocks respectively, and the
difference in the mean vertebral number among them was
significant.
- 8-12
Investigation on the "yoriko"
(herring eggs casted ashore by wave) II. Tamura, T., and Okubo,
S. pp. 95-107. (In Japanese with English summary)(771KB)
Abstract
Some observations of Pacific
herring (Clupea pallasii) eggs were carried out on
Rishiri Island in the northern part of Hokkaido in the spring of
1951 and 1952. "Yoriko" (herring egg mass) at Oshidomari,
Rishiri Island, were estimated about 3,519 m3 in
1951 and 246 m3 in 1952. While the hatching rate of
the eggs exposing in the sunshine for two days decreased
apparently, the eggs which had been wetted by wave hatched out
even after 6 days.
- 8-13
On the egg distribution of Alaska pollack (Theragra
chalcogramma) observed in Funka Bay, 1953 (preliminary
report). Ohigashi, S., and Fujita, T. pp. 109-117. (In Japanese with
English summary)(532KB)
Abstract
From February 12 to March 31,
1953, the distribution of eggs of walleye (Alaska) pollack (Theragra
chalcogramma) in Funka Bay was investigated in conjunction
with the oceanographic conditions. The eggs were collected by
square nets. The eggs were distributed all over the bay, but
they were more frequent in northeastern area than in
southwestern area. The eggs seemed to move inside in the bay in
the later, indicating that the main spawning ground moved
inside.
- 8-14
Experimental studies on
the hatch of the carp-eggs in the treatment of some
disinfectants (preliminary report). Kai, T.
pp. 119-124. (In
Japanese with English summary)(282KB)
Abstract
Effects of several disinfectants
on fungus (Saprolegnia sp.) in carp eggs were evaluated.
Carp eggs treated with sodium chloride, formalin, malachite
green, illuminol, or potassium dichromate showed higher hatching
rate than the untreated ones. The best result was obtained by
the use of 0.5% sodium chloride solution, and the other good
results were obtained by 0.08% potassium dichromate, 1/200,000
Malachite green or 0.5% formalin. Fungus was slightly found in
the use of potassium dichromate and illuminol, while no fungus
was found on eggs treated with other solutions.
- 8-15
On the flounder, Limanda schrenki, taken from the coast
of Nemuro Province. Ito, K. pp. 125-133. (In Japanese with English
summary)(336KB)
Abstract
Cresthead flounder (Pleuronectes
schrenki) captured in the coast of Nemuro, Hokkaido, in May
5-20, 1953, was examined from ecological viewpoints. The fishing
period might be from late April to middle May when the fish
spawn in the coast of Nemuro. The mode of body length was 26-28
cm in female and 22-24 cm in male. It was remarkable that
females were captured more than males, attaining about 2.5 times
in 1953. Number of eggs (Y) contained in the mature ovary
increased in simple proportion to the body length (X). The
relation might be indicated in the following formula: Y=8,515.5X
-1,723,315.6. The average number of eggs was 730,000 (n=32). The
weight of ovary also increased in simple proportion to the body
weight.
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Sci. Rep. Hokkaido Fish Hatchery
7
(1,2), 1952
- 7-1
An ecological study on the salmon fry, Oncorhynchus keta
(1). Sano, S., and Kobayashi, T. pp. 1-10. (In Japanese with English
summary)(480KB)
Abstract
Life history characters of
juvenile chum salmon were preliminary surveyed in the Ishikari
River and on the Ishikari Coast. Juveniles migrated seaward and
offshore at scaled body length (SBL) of 25-55 mm and 60-100 mm,
respectively, in spring. The squamation was initiated at the SBL
of 35 mm. Number of circuli on the scale was 2 in the river and
6 in the coast.
- 7-2
A limnological note on Lake Tokotan of Uruppu Island in the
middle Kurile Islands, with special reference to the utilization
for salmon fishery. Mihara, T. pp. 11-60. (In Japanese with English
summary)(1,948KB)
Abstract
Limnological characters and
migration time of salmonids were observed in Lake Tokotan on
Uruppu Island from May to September in 1940. The adult runs
occurred from June to August for sockeye salmon, in August and
September for pink salmon, and from August to middle November
for chum salmon.
- 7-3
A preliminary note on the natural propagation of dog-salmon,
Oncorhynchus keta. Sano, S. pp. 61-68. (In Japanese)(464KB)
Abstract
Survival of chum salmon eggs and
alevins in redds was examined in experimental and natural
spawning grounds. In the experimental channel, 74.6% of eggs and
63.2% of alevins survived. The survival rate of eggs stocked in
gravel was 92.8% in the Yurappu River and Shiriuchi River.
- 7-4
A survey of the chemical constituents and ichthyo-ecology in
some irrigation canal. Eguchi, H., and Hikita, T. pp. 69-91. (In
Japanese with English summary)(1,579KB)
Abstract
In 1950-52, water analysis and
ecology of freshwater fishes were investigated in an irrigation
canal at Hiragishi near Sapporo. The water was found rich in
both organic and nitrogen matters as compared with other
streams. This might be partly because of the dissolving out of
fertilizing substances used in rice fields. Only five species of
freshwater fishes were obtained: loach (Misgurnus
anguillicaudatus), Siberian stone loach (Noemacheilus
toni), striped pond loach (Lefua nikkonis), Japanese
dace (Tribolodon hakonensis), and crusian carp (Carassius
auratus).
- 7-5
Studies on the food of Atkafish (Pleurogrammus azonus
Jordan & Metz) caught on the breeding ground of herring in
Hokkaido. Tamura, T., and Okubo, S. pp. 93-103. (In Japanese with
English summary)(593KB)
Abstract
The feeding habit of spring
arabesque greenling (Pleurogrammus azonus) was studied on
the breeding ground of Pacific herring (Clupea pallasii)
around Rishiri Island in the spring of 1951-52. The food of
greenlings was varied with season, but on the herring breeding
ground, they fed mostly on herring eggs. Other stomach contents
included Euphasia, sand eel, and small crustaceans. The average
volume of herring eggs contained in the stomachs (n=366) was
18.09 g (=9,300 herring eggs).
- 7-6
Notes on the fishes and aquatic animals found in Lake Notoro in
Hokkaido. Hikita, T. pp. 105-125. (In Japanese with English summary)(1,013KB)
Abstract
Eighty-three fish species and 48
other aquatic animal species were found in Lake Notoro, a
brackish lake along the Okhotsk Sea coast of Hokkaido. It was
notified that they were mostly warm water fishes occurring in
the Okhotsk Sea near Hokkaido.
- 7-7
Study of Lake Abashiri. Diurnal migration of plankton Crustacea
at the position of shallow bay. Ishida, T. pp. 127-131. (In Japanese
with English summary)(241KB)
Abstract
Yobito Bay of Lake Abashiri has a
shallow flat basin whose depth is about 2 m. The plankton
community was coincided with that of deep water area. All
species except Limnoncaea and copepod nauplii descended from
surface water just after day break, and ascended from bottom to
surface water after sun set. General characters of each species
are similar with the result of Motoda and Ishida (1950) made by
the same method at the offshore water of Lake Abashiri.
- 7-8
On the development of Limanda schrenki (Schmidt). Hikita,
T. pp. 133-144. (In Japanese with English summary)(612KB)
Abstract
Cresthead flounder (Pleuronectes
schrenki) spawn in Lake Notoro between late April and early
May. Their minimum maturing age was 3 years old for male and 4
years old for female. The egg development and hatching larvae
were described in this paper.
- 7-9
Some observations of Hokkaido lakes. Ishida, T. pp. 145-155. (In
Japanese with English summary)(482KB)
Abstract
The author noted some fragment
data from limnological observations in lakes of Hokkaido
including Lake Abashiri, Lake Tofutsu, Lake Notoro, Lake
Shikotsu, and Abashiri River. The vertical distribution of
plankton in Lake Abashiri was also recorded.
- 7-10
On the herring found in Akkeshi Bay (1). Sakano, E. pp. 157-161. (In
Japanese with English summary)(176KB)
Abstract
The present study examined the
body size, fecundity, age, and vertebra number of Pacific
herring (Clupea pallasii) (n=353) caught in the Akkeshi
Bay, eastern Hokkaido in the spring of 1952. The fish was
composed of 3-6 years old group, especially 3 years old group
being dominant. The number of ovarian eggs had a linear relation
with the body length. The number of vertebra was distributed
from 52 to 57.
- 7-11
Investigation on the flounder (Limanda schrenki Schmidt)
VI. On the growth rate of flounder, using the otolith in Lake
Notoro. Okubo, S. pp. 163-182. (In Japanese with English summary)(913KB)
Abstract
By using the otolith, the author
estimated the growth rate of cresthead flounder (Pleuronectes
schrenki) which were captured in Lake Notoro from March 1949
to November 1950. The relation between the body length (L) and
the radius of otolith (R) was shown by a formula: Log L=aLog
R+2.3797, where the constant a was 1.653 and 1.5449 for female
and male, respectively.
- 7-12
Studies on the Abashiri River System. Kayama, I., Okamoto, G.,
Ohokura, T., Ohotake, Y., and Morozumi. pp. 183-187. (In
Japanese)(246KB)
Abstract
The authors examined water quality
in the Abashiri River System including Lake Abashiri in the
lower reaches. The lake water was polluted by waste water from
starch factories and inflow of seawater.
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Sci. Rep. Hokkaido Fish Hatchery
6
(1,2), 1951
- 6-1
On the stock of salmon (Oncorhynchus keta Walbaum) in the
coastal waters of Japan and their homing instinct. Sano, S.
pp.
1-10. (In Japanese)(654KB)
Abstract
Chum salmon migrating in the
coastal water of Japan are composed of three stocks: "shirozake"
(white salmon), "tokishirazu", and "akizake" (autumn salmon)
groups. Autumn run chum salmon are divided into 7 groups: South
Kurile, Tohoku, Pacific, Nemuro Bay, Kitami, Ishikari Bay, and
Shiriuchi populations.
- 6-2
Investigation on the yoriko (herring eggs casted ashore by wave)
(I). Tamura, T., Oyamada, H., and Okubo, S. pp. 11-26. (In Japanese)(982KB)
Abstract
Many Pacific herring (Clupea
pallasii) eggs are annually thrown on the shore of Rishiri
Island, Hokkaido. This study investigated to determine
environmental factors affecting survival rate of herring eggs.
Herring eggs could survive for 7days after being thrown on the
shore under cloudy and low temperature condition. However,
sunlight reduced the survival rate of eggs within 30 minute.
Herring eggs could survive in fresh water for one week.
- 6-3
Studies on the change of fishing conditions of salmon in
Hokkaido (I) (the fishing conditions on salmon). Mihara, T.,
Ito, S., Hachiya, T., and Ichikawa, M. pp. 27-133. (In Japanese)(6,174KB)
Abstract
Coastal catch during 1904-1925,
river catch and the number of released fry before 1925 were
surveyed for chum salmon fisheries in Hokkaido. Coastal and
river catches fluctuated in 4-5 years cycle and tended to
enlarge in long term. Local coastal catches were varied
independently with that of other localities. Water temperature
ranged 13-18°C in the peak of river catch, and 10-13°C in the
peak of coastal catch by set nets. A significant correlation was
observed among coastal, river catches, and fry releases from
hatcheries. A comparison between estimated natural spawning and
seaward migrating fry originated from hatcheries indicated that
artificial enhancement increased the stock size of chum salmon.
- 6-4
On the cod, Gadus macrocephalus tilesius, caught off the
coast of Rebun Island. Sakano, E. pp. 135-144. (In Japanese)(374KB)
Abstract
Age, body size, sex ratio were
determined in Pacific cod (Gadus macrocephalus) caught
off the coast of Rebun Island between January and May in 1949.
The fish ranged from 3 to 10 years old, being predominant at 5-6
years old. Female was more abundant than male until the middle
of March.
- 6-5
Investigation on the flounder (Limanda schrencki) (V).
The growth-rate obtained from the results of marking experiments
and the feeding habit. Okubo, S. pp. 145-150. (In Japanese)(250KB)
Abstract
The growth rate and feeding habit
of cresthead flounder (Pleuronectes schrenki) were
examined by tagging experiments conducted in Lake Notoro in the
spring and fall of 1949. The growth rate was not determined in
this experiment. The flounder fed mainly on crustaceans and
chaetopods in the bottom.
- 6-6
Studies on the River Ishikari (II). Okamoto, G., Ohokura, T.,
Ohotake, Y., Kayama, I., and Ohokura, M. pp. 151-166. (In Japanese)(652KB)
Abstract
Water quality was examined in the
Ishikari River System in the winter and the snow-melt period of
spring, 1951. In addition, seasonal changes of water quality in
the river were reviewed.
- 6-7
Chemical constituents inland waters in Hokkaido Japan (II).
Studies on the constituents of water of the main river in
Hokkaido, Japan, which spawning migration of the dog salmon.
Eguchi, H. pp. 167-172. (In Japanese)(257KB)
Abstract
The author examined water quality
in 36 rivers of Hokkaido during the spawning migration season of
chum salmon between October and December, 1950. Water
temperature, pH, MnO4K, NH3-N, SiO2,
Cl, SO3, Ca, and soluble total solids were recorded
in this paper.
- 6-8
On the egg and larvae of Limanda schrencki and the
synonymatic problem between L.schrencki and
L. yokohamae. Yamamoto, K. pp. 173-179. (In Japanese)(412KB)
Abstract
Eggs and larvae of cresthead
flounder (Pleuronectes schrenki) were described.
Cresthead flounder was morphologically similar with marbled sole
(P. yokohamae). Further studies are requested for the
taxonomic problem between these species.
- 6-9
On quantative collection and holizontal distribution of plankton
Crustacea. Ishida, T. pp. 181-190. (In Japanese)(497KB)
Abstract
In Lake Abashiri, a shallow
eutrophic lake, the plankton collection was difficult, because
most crustacean planktons were distributed in the bottom. In
Lake Shikotsu, an oligotrophic lake, the horizontal distribution
of planktons was disproportionate.
- 6-10
Notes on the fish fauna of Volcano Bay in Hokkaido (II). Hikita,
T. pp. 191-209. (In Japanese)(868KB)
Abstract
In the Funka Bay, western
Hokkaido, 82 fish species belonging to 22 families were
recorded.
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Sci. Rep. Hokkaido Fish Hatchery
5
(2), 1950
- 5-2
An
improvement of egg incubator. Kimura, T., Eguchi, H., and Okubo, S. pp. 97-104. (In
Japanese)(530KB)
Abstract
The authors developed a new egg
incubator, replacing Atkins incubator. It is called "Kimura
style incubator", and has high capacity with low water supply.
Hatching alevins can develop in this incubator till the yolk
absorption stage.
- 5-3
An
observation on the diurnal migration of plankton crustaceans at Lake Abashiri,
Hokkaido, in summer of 1947. Motoda, S., and Ishida, T. pp. 105-112. (In Japanese
with English summary)(459KB)
Abstract
Diaphanosoma brachyurum,
Sinocalanus tenellus and Bosmina longirostris were
collected for the study of their vertical movement in Lake
Abashiri. They escaped from surface water just after day break,
and then most of them were distributed in deeper layers during
morning. The layer of maximum abundance, however, became
shallower in afternoon. During night the crustaceans were
distributed almost evenly throughout the vertical range, showing
neutral condition to the geotropism. It was highly probable that
the plankton crustaceans were concentrated near the bottom
during the daytime, where Japanese smelts migrated to feed them.
- 5-4
Study
on Lake Abashiri: water quality and stratification. Ishida, T. pp. 113-117. (In Japanese)(240KB)
Abstract
In Lake Abashiri, the author
surveyed the water quality including phosphate, potassium
permanganate, and phytoplankton.
- 5-5
A data
on water quality in Hokkaido (1). Eguchi, H., and Hara, S. pp. 118-126. (In
Japanese)(470KB)
Abstract
A data base of water quality for
fish culture in Hokkaido was established. The data included
water temperature, pH, O2, MnO4K, NH3-N,
SiO2, Cl, SO3, CaO, P2O5,
and soluble total solids.
- 5-6
Fish
fauna in the Funka Bay (I). Hikita, T. pp. 127-139. (In Japanese)(608KB)
Abstract
A total of 141 species belonging
to 58 families was recorded from Funka Bay, of which two species
were first record in Japan.
- 5-7
Study
on cresthead flounder IV. Body length and fecundity. Ishida, R. pp. 140-144. (In
Japanese)(241KB)
Abstract
Fecundity of cresthead flounder (Pleuronectes
schrenki) in Lake Notoro was not affected by the body size
or maturity. A relation between mean number of eggs (N) obtained
from a fish and body length (L) was described by a formula:
N=4730L3.5.
- 5-8
A study on the Ishikari River System (1). Okamoto, G., Ohokura, T., Ohotake, Y.,
Kayama, I., and Ohokura, M. pp. 145-161 (In Japanese)(804KB)
Abstract
The water quality was assessed in
the Ishikari River System in 1950. The water quality was
characterized by low pH, and high concentration of silicic acid
and organic matters. It was polluted by waste and sewage waters
from town, factories, and mines around the upstream.
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Sci. Rep. Hokkaido Fish Hatchery
5
(1), 1950
- 5-1
A
limnological review of lakes in Hokkaido. Motoda, S. pp. 1-96. (In Japanese)(6,332KB)
Abstract
The author reviewed limnology of 44 lakes in Hokkaido.
The paper included the geographical characters, water quality, plankton fauna,
and fish and aquatic animal fauna.
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Sci. Rep. Hokkaido Fish Hatchery
4
(2), 1949
- 4-6
Study
on methods to fertilize salmonid eggs. Yamamoto, K. pp. 33-46. (In Japanese)(1,106KB)
Abstract
The activity of chum salmon sperms is maintained
for 16 hours at 3-6°C without dilution, although it is only for one minute when
exposed in fresh water. Salmonid eggs also lose their fertilization ability in
fresh water, maybe because a micropyle is closed after being activated in fresh
water. In balanced salt water, the sperms and eggs can maintain their activity,
but not be fertilized since no fertilization waves occur after sperm entering
eggs. The fertilization is controlled by ion concentration, and it never occur
under 0.1 M ion concentration.
- 4-7
Study
on feeding habit of Japanese smelt in Lake Abashiri. Ishida, T. pp. 47-56. (In
Japanese)(571KB)
Abstract
In Lake Abashiri, Japanese smelt (Hypomesus
nipponensis) fed mainly on mysids, crustacean plankton, larvae of Diptera,
and Japanese icefish (Salangichthys microdon). They never fed on
phytoplankton and rotifer. In autumn, the pond smelt was divided into two types:
sea and resident types. Only sea type smelt fed on mysids, suggesting that both
types had different feeding area each other. The crustacean plankton fauna was
different between the stomach contents of smelt and plankton net samples.
- 4-8
Feeding habit of dace in the Bibi River. Inukai, T. pp. 57-61. (In Japanese)(296KB)
Abstract
The author examined the stomach contents of
rosyface dace (Tribolodon ezoe) and Japanese dace (T. hakonensis)
collected from the Bibi River between March and September, 1946-48. Most fish
(85%) had an empty stomach. Aquatic insects were dominant in the stomach
contents. Many parasitic nematodes were found in the intestine.
- 4-9
Research on cresthead flounder III. Tagging experiment in Lake Notoro. Ishida,
R. pp. 62-72. (In Japanese)(611KB)
Abstract
In Lake Notori, 985 tagged cresthead flounder (Pleuronectes
schrenki) were released. 159 fish were recaptured in the lake, but there was
no recapture in other areas. This tagging result indicated that cresthead
flounder migrated within the lake.
- 4-10
Water
quality in alpine lakes in Niseko. Eguchi, H. pp. 73-75 (In Japanese)(152KB)
Abstract
Survey of water quality was conducted in three
alpine lakes (Oh-numa, Naga-numa, and Shinzen-numa) in Niseko mountains.
- 4-11
Ecology of kokanee salmon (Oncorhynchus nerka) in Lake Shikotsu-1.
Ohigashi, S., and Okubo, S. pp. 76-78. (In Japanese)(162KB)
Abstract
Body size, sex ratio, age composition, and scale
pattern were examined for lacustrine sockeye salmon (n=707) captured in Lake
Shikotsu from May 1948 to August 1949. The ratio of females increased from
summer to the spawning season, being 84% in late October (a peak of spawning).
The age composition indicated 73% of 4 years and 20% of 5 years old fishes.
- 4-12
Growth
characters of chum salmon in several rivers of Hokkaido estimated by scale
pattern-2. Growth of chum salmon in Abashiri and Tokoro Rivers. Kubo, T. pp. 79-94.
(In Japanese)(1,157KB)
Abstract
The growth of adult chum salmon returning to the
Abashiri River and Tokoro River was examined by scale pattern. The body and
scale sizes were genetically determined: Tokoro stock had larger body size than
Abashiri stock every year. The growth in the first year of life seemed to be
controlled by environments, but the further growth showed variation due to a
compensation. The growth rate in the first year might be related with a trend of
cold current.
- 4-13
Maturation of chum salmon (Oncorhynchus keta) induced by the pituitary
gland of chum salmon. Nishino, K. pp. 95-97. (In Japanese)(207KB)
Abstract
Pituitary gland powder of chum salmon was injected
in the body cavity of maturing chum salmon at 35 mg per fish. The injected fish
spawned 10-15 days earlier than the normal fish in the Tokachi River. However,
the fertilization rate of the eggs was low (49%).
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Sci. Rep. Hokkaido Fish Hatchery
4
(1), 1949
- 4-1
A
limnological investigation of Lake Abashiri, Hokkaido, with particular reference
to the plankton fauna and flora. Motoda, S., and Ishida, T. pp. 1-9. (In Japanese
with English summary)(590KB)
Abstract
The hydrography and plankton community were
monthly observed in Lake Abashiri, Hokkaido, in 1947. The plankton fauna
included 46 species. When the lake was covered with ice in winter, the plankton
fauna was poor, but considerable number of Sinocalanus tenellus and
Synchaeta spp. were present. Sinocalanus tenellns was dominant
throughout the year. Abundance of Cyclops strennus and Mesocyclops
hyalinus increased in spring and summer, respectively. The cladoceran
Diaphanosoma brachyurum appeared abundantly during summer. The rotifer
Synchaeta spp. were abundant in winter, and Polyarthra trigla and
Keratella cochlearis were present in the other seasons. The phytoplankton
Aphanizomenon flosaquae increased in summer and autumn. The vertical
distribution of plankton was studied for several species.
- 4-2
A
survey on water quality of carp ponds. Eguchi, H., and Okubo, S. pp. 10-15. (In
Japanese)(416KB)
Abstract
Daily change of water temperature, dissolved
oxygen, and pH was monitored in various carp rearing ponds during summer. The
dissolved oxygen concentration decreased during night, reaching in the minimum
level at dawn. The pH also decreased in night. Water quality in ponds was
influenced by phytoplankton.
- 4-3
Ecological survey of northern fishes 1. Coastal fishes in Rakuma, Sakhalin (2).
Yamamoto, K. pp. 16-26. (In Japanese)(668KB)
Abstract
Ecological aspects were described for 38 fish
species collected in the shallow water off Rakuma on Sakhalin Island. The fish
fauna was most abundant in the early period of summer and fall, but poor in
summer due to an increase of water temperature. The fish fauna included 32
marine and 6 freshwater species, of which 19 species were migrating fish.
- 4-4
Effects of low oxygen concentrations on fertilization and development of chum
salmon eggs. Okubo, S. pp. 27-29. (In Japanese)(146KB)
Abstract
A low oxygen concentration (8.6-20%) suppressed
the development of chum salmon eggs. Abnormal embryonic formation occurred in
64-95% of eggs exposed to the low oxygen water for 24 hours.
- 4-5
Promotion of maturation in masu salmon by the pituitary gland of chum salmon.
Ishikawa, H., Hashimoto, T., and Takahashi, Y. pp. 30-32. (In Japanese)(167KB)
Abstract
It is difficult to take eggs from adult masu
salmon, because they migrate to fresh water several months before spawning. The
authors successfully promoted maturation of adult masu salmon by injecting chum
salmon pituitary gland.
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Sci. Rep. Hokkaido Fish Hatchery
3
(2), 1948
Back
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-
Sci. Rep. Hokkaido Fish Hatchery
3
(1), 1948
- 3-1
Water
quality and plankton fauna in Lake Abashiri (1). Motoda, S., and Ishida, T.
pp.
1-12. (In Japanese)(708KB)
Abstract
A seasonal change of plankton fauna was surveyed
in Lake Abashiri, a brackish lake along the Okhotsk Sea coast in 1947. Forty six
species were recorded in this survey. Plankton fauna was poor during the
ice-covered period in winter, but nauplii of Cyclops appeared after
ice-melting. Copepods and a phytoplankton (Aphanizomenon flosauae) were
predominant in the early summer. Bosmina longirostris and Diaphanosoma
brachyurum increased their number in July and August, respectively. In
September, abundance of these cladocerans decreased, but number of copepods
increased again.
- 3-2
Culture of carp using white Dutch clover as a diet. Eguchi, H. pp. 13-15. (In
Japanese)(195KB)
Abstract
Carp (2 years old) were fed by diet with white
Dutch clover for 2 months in 1943. This diet improved the growth of carp very
well, while a standard diet including silkworm powder and absorbent sugar caused
a loss of appetite.
- 3-3
Regional differences of cresthead flounder (Pleuronectes schrenki).
Ishida, R. pp. 16-22. (In Japanese)(377KB)
Abstract
Geographical variation of morphology was examined
for various populations of cresthead flounder (Pleuronectes schrenki)
from Hokkaido coasts of the Pacific Ocean, Japan Sea, and Okhotsk Sea. The
results suggested that each population was independent. Lake Notoro population
was apparently different from other ocean populations, being considered as a
lake population.
- 3-4
Effects of the pituitary gland of chum salmon on the spawning of rainbow trout
(1). Nishino, K. pp. 23-28. (In Japanese)(467KB)
Abstract
The pituitary gland of chum salmon could promote
maturation of rainbow trout 20-30 days earlier than normal fish. The injection
of pituitary gland was more effective for the body cavity than for the muscle.
Eggs produced by promoted rainbow trout had a good quality as normal fish did.
- 3-5
Downstream migration of kokanee salmon (Oncorhynchus nerka) in Lake
Shikotsu (preliminary report). Ohigashi, S., Kubo, T., and Okubo, S. pp. 29-32. (In
Japanese)(231KB)
Abstract
Lacustrine sockeye salmon (“himemasu”) was known
to show a downstream migration from Lake Shikotsu. To prevent these migrations,
a net set in the outlet of lake (the Chitose River) was effective in 1946. Down
stream migrating fish were immature, and most of them were 4 years old.
- 3-6
Bibliography of ecology, culture, and hatching of salmonids. Sano, S. pp. 33-34. (In
Japanese)(135KB)
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Sci. Rep. Hokkaido Fish Hatchery
2
(1), 1947
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2-1
A mechanism in fertilization of chum salmon eggs reduced by
fresh water. Yamamoto, K. pp. 1-11. (In Japanese)(697KB)
Abstract
The fertilization ability of chum
salmon eggs was reduced within 2 minutes after a contact with
fresh water, and completely lost within 30 minutes after that.
It was well maintained in balanced salt water. Eggs were
activated after a contact with fresh water, and a Scheidewand
formed in the eggs. A fertilization wave following egg
activation might reduce the fertilization ability of eggs.
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2-2
Seasonal changes in water quality of the Naibetsu River in
Chitose Hatchery. Eguchi, H., and Hara, S. pp. 12-15.(In Japanese)(191KB)
Abstract
Water quality was monthly
monitored in the Naibetsu River near Chitose Hatchery for one
year from April, 1946. The water temperature was rarely
influenced by air temperature during summer, and higher than air
temperature during late fall and winter. The pH was stable
around 7.0, and the oxygen concentration was also stable over
90%.
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2-3
Growth characters of chum salmon in several rivers of Hokkaido
estimated by scale pattern (I). Kubo, T. pp. 16-25.(In Japanese)(518KB)
Abstract
Scale pattern of adult chum salmon
was compared among eight populations from the Shiriuchi River,
Chitose River, Teshio River, Abashiri River, Nishibetsu River,
Tokachi River, Yubetsu River, and Shokotsu River in Hokkaido.
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2-4
Effects of vitamin B on the mortality of juvenile rainbow trout.
Tanaka, M. pp. 26-34.(In Japanese)(424KB)
Abstract
Diets mixed with vitamin B1 and B2
could improve the survival and growth rate of rainbow trout.
Vitamin B1 alone could not increase the fish growth, causing a
hypertrophy of the liver in dead fish.
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2-5
Study on cresthead flounder 1. On cresthead flounder and black
plaice. Yamamoto, K., and Ishida, R. pp. 35-40.(In Japanese)(408KB)
Abstract
Cresthead flounder (Pleuronectes
schrenki) is morphologically similar with black plaice (P.
obscurus), but differs from the latter in the structure of
pharyngeal tooth. Cresthead flounder has large body and
population, and spawns in the coasts facing the open sea with a
peak in middle May. Black plaice has small body and population,
living in coastal brackish water throughout the year. The
spawning season of black plaice is earlier than that of
cresthead flounder. Eggs of cresthead flounder has a thick
gelatin layer, comparing with these of black plaice.
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2-6
Research on silvery adult chum salmon during the upstream
migrations (2). Sano, S. pp. 41-45.(In Japanese)(272KB)
Abstract
Following the previous report
(1-5), the author examined silvery adult chum salmon returning
to the Chitose River in January and thereafter. The results were
similar with the previous ones.
-
2-7
A method to determine number of salmon eggs. Suetake, T. pp.
46-50.(In Japanese)(165KB)
Abstract
The author evaluated methods to
estimate number of salmonid eggs on Atkins incubator.
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2-8
Ecological study on adult chum salmon migrating to rivers in
Hokkaido-2. Sano, S., and Kubo, T. pp. 51-58.(In Japanese)(404KB)
Abstract
To determine population
characteristics of chum salmon in Hokkaido, the authors compared
the migration period, morphology, body size, number of lateral
scales and gill raker, age composition, and sex ratio among chum
salmon stocks from the Shiriuchi River, Abashiri River, Chitose
River, Tokachi River, Shibechari (= Shizunai) River, Nishibetsu
River, and Teshio River in 1946-47.
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2-9
Study on ecology of rainbow trout in Lake Mashu-1. Mihara, T.
pp.
59-68.(In Japanese)(454KB)
Abstract
A ecological study was conducted
for rainbow trout and steelhead trout released in Lake Mashu,
eastern Hokkaido. Both species could not be distinguished by
morphological characters. Their spawning season was between
middle May and July. Four and five years old fish were dominant,
and a mode of body length showed around 35 cm.
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Sci. Rep. Hokkaido Fish Hatchery
1 (1), 1946
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1-1
Ecological study on adult chum salmon migrating to rivers in
Hokkaido-1. Sano, S., and Kubo, T. pp. 1-11. (In Japanese)(594KB)
Abstract
Migration time and morphological
character were examined in adult chum salmon returning to six
rivers in Hokkaido during 1945-46. The peak of river returns was
October in the Tokachi and Abashiri River, December in the
Shiriuchi River, and October-November and December in the
Chitose and Nishibetsu River. The adult body size and number of
lateral scales were largest in the Shiriuchi River population.
The relative head length was larger in populations along the
Japan Sea coast. The depth of caudal peduncle was smallest in
the Chitose River population, and largest in the Tokachi River
population.
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1-2
Maturation of adult masu salmon (Oncorhynchus masou)
stocked in a pond. Igarashi, S. pp. 13-18. (In Japanese)(276KB)
Abstract
Maturing masu salmon were stocked in a
pond after they had returned to the Nobusha River in the late
June of 1944-45. The holding pond was supplied with 15-18°C
water. More than 90% of adults matured by the end of September.
They did not feed during the holding period. It may be important
for holding of adult masu salmon to supply enough water to the
holding pond.
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1-3
Effects of low temperatures on the development of chum salmon
eggs. Yamamoto, K. pp. 19-34. (In Japanese)(928KB)
Abstract
The freezing point of chum salmon eggs
was -0.62°C in unfertilized eggs and -0.46°C in fertilized eggs.
Eggs survived in supercooling condition, but died in -2-4°C.
Sperms survived in -4°C for 1 h. The author noted effects of low
temperature on salmon eggs treated at hatcheries.
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1-4
A rearing experiment of carp (Cyprinus carpio) in flowing
ponds in Hokkaido. Eguchi, H. pp. 35-38. (In Japanese)(162KB)
Abstract
Juvenile carp were reared in flowing
ponds during July-October, 1947. The juveniles were fed by
absorbent silkworm, soy sauce dregs, clover, and others. The
carp weight increased 3-4 times for 3-4 months, but some fish
died due to fungus diseases and others.
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1-5
Research on silvery adult chum salmon in the Chitose River.
Sano, S. pp. 39-43. (In Japanese)(258KB)
Abstract
The occurrence of silvery chum salmon
returning to the Chitose River was examined in the autumn and
winter of 1945-46. The rate of silvery salmon was low in
December, but increased in January. The silvery chum salmon had
reddish muscle, which contained lower water content and higher
nitrogen comparing with that of common salmon.
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1-6
Population size of Japanese smelt enhanced in Lake Akan. Mihara,
T. pp. 45-50. (In Japanese)(300KB)
Abstract
The author estimated the maximum
abundance of Japanese smelt (Hypomesus nipponensis) was
120 tons in Lake Akan. The population size of smelts was
influenced by abundance of zooplankton.
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1-7
Predation by fishes on salmonid fry in rivers. Kubo, T. pp. 51-55.
(In Japanese)(262KB)
Abstract
To examine the predation of salmon, seven
species of freshwater fishes were collected from rivers on
Hokkaido, Iturup, and Kunashiri. The major salmon predator was
whitespotted charr (Salvelinus leucomaenis) and Japanese
dace (Tribolodon hakonensis). Dolly Varden (Salvelinus
malma) also fed salmon juveniles in rivers on Iturup and
Kunashiri Islands.
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