280
J. H. S. BLAXTER AND F. 0. T. IIOLLIDAY
uncontrolled conditions (e.g. Pearson, 1952). The very small larvae of
Sardinops, for example, make the successful rearing of these species a
great challenge.
E. Farming
In 30me clupeids a form of fish farming has been attempted. For
instance, Williamson (1909), using low temperatures, retarded the
development of herring eggs so that they might be transported to New
Zealand ; this attempt failed. Japanese workers (see under Isasaki in
Scattergood, 1957) tried to improve the fishery for Clupea pallasii at
Akkeshi-machi in the early 1930's. Motoda and Hirano (1961) described experiments from 1939-1949 in which 2 x 10" eggs of Clupea
pallasii were transported on the west coast of Hokkaido in order to see
whether the fishery could be improved, but without any apparently
beneficial result. Bibov (1960), howcver, reported a successful project
where 19 million herring eggs were transported from the Baltic to the
h a 1 Sea between 1954-1966, resulting in thc formation of a new stock
there, the fish having established themselves to the extent of growing
and spawning. The growth in length was up to one and a half times that
in the Baltic and the growth in weight four times, and the fecundity
five times, as great as the original parent stock. The importance of this
type of project, which gives valuable ideas as to the plasticity of the
characteristics of a species, cannot be overestimated.
I n the shad A h a sapidissima, pond culture has been successfully
carried out on the eastern coast of the United States since the end of
the last century. Recent publications on the subject are those of
Pearson (1952) and Maxfield (1953).
Murphy (1960) and Hida and Thomson (1902) rcportad the estahlishment of Harengula vittata and Doroarno petlemcnar, renpccti vcly in
Hawaiian waters as bait fish for tuna.
F. Mortality o j lurvue
During the period from hatching to metamorjhnirr, it, hrtn tjmn
questioned whether clupeid larvae go through critical p c r i o h whwi
high mortalities occur, for instancc at the stagt: wtwrt: thc lervac:
change from their yolk to external food sourcc8. High mortalitics of
hcrring larvac have been reported at sea by Soleim (1942). Bowers and
Williamson (1951) commented on published work Hhowing a low
percentage of guts of herring larvw containing food. Idow jwrcentagw
may be due to extrusion of gut contents on capture and need not
necessarily bc a sign of poor feeding conditions or low survival rate of
larvae. Hempel and Blaxter (1961b) measured the condition factor of
J. H. S. BLAXTER AND F. 0. T. IIOLLIDAY
uncontrolled conditions (e.g. Pearson, 1952). The very small larvae of
Sardinops, for example, make the successful rearing of these species a
great challenge.
E. Farming
In 30me clupeids a form of fish farming has been attempted. For
instance, Williamson (1909), using low temperatures, retarded the
development of herring eggs so that they might be transported to New
Zealand ; this attempt failed. Japanese workers (see under Isasaki in
Scattergood, 1957) tried to improve the fishery for Clupea pallasii at
Akkeshi-machi in the early 1930's. Motoda and Hirano (1961) described experiments from 1939-1949 in which 2 x 10" eggs of Clupea
pallasii were transported on the west coast of Hokkaido in order to see
whether the fishery could be improved, but without any apparently
beneficial result. Bibov (1960), howcver, reported a successful project
where 19 million herring eggs were transported from the Baltic to the
h a 1 Sea between 1954-1966, resulting in thc formation of a new stock
there, the fish having established themselves to the extent of growing
and spawning. The growth in length was up to one and a half times that
in the Baltic and the growth in weight four times, and the fecundity
five times, as great as the original parent stock. The importance of this
type of project, which gives valuable ideas as to the plasticity of the
characteristics of a species, cannot be overestimated.
I n the shad A h a sapidissima, pond culture has been successfully
carried out on the eastern coast of the United States since the end of
the last century. Recent publications on the subject are those of
Pearson (1952) and Maxfield (1953).
Murphy (1960) and Hida and Thomson (1902) rcportad the estahlishment of Harengula vittata and Doroarno petlemcnar, renpccti vcly in
Hawaiian waters as bait fish for tuna.
F. Mortality o j lurvue
During the period from hatching to metamorjhnirr, it, hrtn tjmn
questioned whether clupeid larvae go through critical p c r i o h whwi
high mortalities occur, for instancc at the stagt: wtwrt: thc lervac:
change from their yolk to external food sourcc8. High mortalitics of
hcrring larvac have been reported at sea by Soleim (1942). Bowers and
Williamson (1951) commented on published work Hhowing a low
percentage of guts of herring larvw containing food. Idow jwrcentagw
may be due to extrusion of gut contents on capture and need not
necessarily bc a sign of poor feeding conditions or low survival rate of
larvae. Hempel and Blaxter (1961b) measured the condition factor of