THE ARTIBIOIAL PROPAGATION OB MABXNE FISH
23
with periodically refreshed or running sea water. These aquaria were
replaced by glazed earthenware drain pipes, about 30.5 cm diameter
md 76 cm long. The bottom of each pipe waa fitted with a cement
plug and a constant level device. Cultures of dgae and flagellates
tried aa food for larval fish, also Balanua end A M i a nauplii,
together with the larval forms of Pomatocerw, YytiZua and Oetrea.
The firet results in 1946 were encouraging; mackerel and lemon sole
fry took oyster larvae and Artenzia nauplii, but few survivd to an
advanced stage of larval development. In 1946, almost 20% of newlyhatched herring larvae grew to a size large enough for the vertebrae
fo be counted. A total of 600 sole were reared beyond metamorphosis
and a few mackerel also survived. Dannevig attributed this succ8ss
to technical improvements, perticularly the w of earthenware tanks,
and the filtration of hatchery aea water in such a manner m to bring
its dissolved gas content into equilibrium with that of the atmosphere.
Dannevig and Dannevig (1950) and Dannevig and Hansen (1962)
described further experimental work at Fledevigen, on factora involved
in the hatching and rearing of marine fish eggs and larvae. Their
reports discuas, in
general manner, the possible causes of larval
mortality in aquaria, including " gas diseaae " (appearance of intestinal
air-bubbles), fungal, flagellate and bacterial attack, and the effect of
metabolites. Little preoiae information is given regarding the magnitude of larval survival to a specified stage of development; but it is
olear that considerable numbers of a variety of fieh speciea were reared
beyond metamorphosis. In 1952, there were good samples of &monthold hening, &month and 18-month-old plaice and 5-year-old sole at
the Fldevigen hatchery-all reared from artificially fertilized or
pond-spawned eggs.
With the exception of Norwegian researoh, poet-war attempt8 to
m u marine fish larvae have been undertaken in the wider context of
edogy, physiology and taxonomy, rather than preotical h h cult-.
They include work on the family Atherinidae (MoHugh and Waker,
1948); CZupea pdZmii Val. by McMynn and Hoar (1953); CZqea
b e n g u s by Buckmann d al. (1963) and Cekngraulis rnetiCetW,
@tinther), the anchoveta, by Klima et d. (1962). Morris (1966)
dmoribed experiments in which five species of marine fieh larvae from
d e m e d eggs were reared beyond metamorphosis in cylindricsl stoneW a r e orocks containing about 28 1. of 888 water. 10-70% survivale
Were claimed, to a stage of development when further growth wae
simply a matter of maintenance. High mortalities occurred among
Pelagio eggs of several different species, incubated in an appazatus
resembling that designed by Fabre-Domergue, shown in Fig. 3.
A.Y.B.--O
B
23
with periodically refreshed or running sea water. These aquaria were
replaced by glazed earthenware drain pipes, about 30.5 cm diameter
md 76 cm long. The bottom of each pipe waa fitted with a cement
plug and a constant level device. Cultures of dgae and flagellates
tried aa food for larval fish, also Balanua end A M i a nauplii,
together with the larval forms of Pomatocerw, YytiZua and Oetrea.
The firet results in 1946 were encouraging; mackerel and lemon sole
fry took oyster larvae and Artenzia nauplii, but few survivd to an
advanced stage of larval development. In 1946, almost 20% of newlyhatched herring larvae grew to a size large enough for the vertebrae
fo be counted. A total of 600 sole were reared beyond metamorphosis
and a few mackerel also survived. Dannevig attributed this succ8ss
to technical improvements, perticularly the w of earthenware tanks,
and the filtration of hatchery aea water in such a manner m to bring
its dissolved gas content into equilibrium with that of the atmosphere.
Dannevig and Dannevig (1950) and Dannevig and Hansen (1962)
described further experimental work at Fledevigen, on factora involved
in the hatching and rearing of marine fish eggs and larvae. Their
reports discuas, in
general manner, the possible causes of larval
mortality in aquaria, including " gas diseaae " (appearance of intestinal
air-bubbles), fungal, flagellate and bacterial attack, and the effect of
metabolites. Little preoiae information is given regarding the magnitude of larval survival to a specified stage of development; but it is
olear that considerable numbers of a variety of fieh speciea were reared
beyond metamorphosis. In 1952, there were good samples of &monthold hening, &month and 18-month-old plaice and 5-year-old sole at
the Fldevigen hatchery-all reared from artificially fertilized or
pond-spawned eggs.
With the exception of Norwegian researoh, poet-war attempt8 to
m u marine fish larvae have been undertaken in the wider context of
edogy, physiology and taxonomy, rather than preotical h h cult-.
They include work on the family Atherinidae (MoHugh and Waker,
1948); CZupea pdZmii Val. by McMynn and Hoar (1953); CZqea
b e n g u s by Buckmann d al. (1963) and Cekngraulis rnetiCetW,
@tinther), the anchoveta, by Klima et d. (1962). Morris (1966)
dmoribed experiments in which five species of marine fieh larvae from
d e m e d eggs were reared beyond metamorphosis in cylindricsl stoneW a r e orocks containing about 28 1. of 888 water. 10-70% survivale
Were claimed, to a stage of development when further growth wae
simply a matter of maintenance. High mortalities occurred among
Pelagio eggs of several different species, incubated in an appazatus
resembling that designed by Fabre-Domergue, shown in Fig. 3.
A.Y.B.--O
B