278
J. H. 8 . BLAXTER AND F. a. T. HOLLIDAY
weight of Scottish (Clyde) herring larvae with length. Growth will
vary as a result of biotic and abiotic factors as well as inherent ones
such aa yolk supply (Toom, 1958; Blaxter and Hempel, 1963). Few
attempts have been made to correlate growth rates from year to year
and place t o place with such factors.
Growth rates have been studied in aquaria to a small extent.
Meyer (1878a) and Schach (1939), using wild plankton as food, reared
herring larvae whose growth rate was similar to that in the sea. They
found the growth rate dropped when plankton was scarce. The best
growth waa found by Schach to be in the largest tanks. Blaxter and
Hempel (1961) found an increased growth rate in reared herring larvae
when coarser plankton was used as food. Blaxter (1962) found some
evidence for better growth of herring larvae at higher temperatures and
in larger tanks. Nikitinskaya (1958b), hatching larvae of CZwpea
pauaSii, obtained less active and less well-developed larvae in temperatures outside the average of 3-6"C, and from the later hatchings a t
3-6°C. Farris (1960) suggested that the overall growth of young Saydinops cueruba larvae was best approximated by two curves, an
initial logarithmic and a subsequent exponential one. A common
finding of many authors rearing fish larvm is the great size range
of larvae of the same origin kept in the same tank, in conditions
of apparently abundant food (discussed in Section VI, E).
Another finding has been some abnormality of growth, mainly a
foreshortening of the head region, as that described by Buckmann
et al. (1953) for herring larvae. Nikolsky et d. (1961) analysed the
variation in length of young herring from Norway and the Baltic
(" salaka 'I). The Norwegian herring showed less variability, whiah
they related to the greater stability of feeding condition8 in the ocoan.
D. Rearing of larvae
The successful rearing of herring and CZqea pdlaeii beyond the
yolk sac stage has been achieved by a number of workers aa e m -
marked in Table 111.
Morris (1956) gave a valuable review of marine fish rearing, particularly from the feeding point of view. From a study of this and
published work in the table, the following facilities appear to be
desirable for successful rearing : tanks with opaque walls, running sea
water, even overhead illumination and a source of wild plankton
(Bahnw nauplii, obtained from the adults before spawning, also being
eatisfactory ).
Little success seems to have been met with in rearing clupeib othor
than herring, though A h u species have been reared in pondn in
J. H. 8 . BLAXTER AND F. a. T. HOLLIDAY
weight of Scottish (Clyde) herring larvae with length. Growth will
vary as a result of biotic and abiotic factors as well as inherent ones
such aa yolk supply (Toom, 1958; Blaxter and Hempel, 1963). Few
attempts have been made to correlate growth rates from year to year
and place t o place with such factors.
Growth rates have been studied in aquaria to a small extent.
Meyer (1878a) and Schach (1939), using wild plankton as food, reared
herring larvae whose growth rate was similar to that in the sea. They
found the growth rate dropped when plankton was scarce. The best
growth waa found by Schach to be in the largest tanks. Blaxter and
Hempel (1961) found an increased growth rate in reared herring larvae
when coarser plankton was used as food. Blaxter (1962) found some
evidence for better growth of herring larvae at higher temperatures and
in larger tanks. Nikitinskaya (1958b), hatching larvae of CZwpea
pauaSii, obtained less active and less well-developed larvae in temperatures outside the average of 3-6"C, and from the later hatchings a t
3-6°C. Farris (1960) suggested that the overall growth of young Saydinops cueruba larvae was best approximated by two curves, an
initial logarithmic and a subsequent exponential one. A common
finding of many authors rearing fish larvm is the great size range
of larvae of the same origin kept in the same tank, in conditions
of apparently abundant food (discussed in Section VI, E).
Another finding has been some abnormality of growth, mainly a
foreshortening of the head region, as that described by Buckmann
et al. (1953) for herring larvae. Nikolsky et d. (1961) analysed the
variation in length of young herring from Norway and the Baltic
(" salaka 'I). The Norwegian herring showed less variability, whiah
they related to the greater stability of feeding condition8 in the ocoan.
D. Rearing of larvae
The successful rearing of herring and CZqea pdlaeii beyond the
yolk sac stage has been achieved by a number of workers aa e m -
marked in Table 111.
Morris (1956) gave a valuable review of marine fish rearing, particularly from the feeding point of view. From a study of this and
published work in the table, the following facilities appear to be
desirable for successful rearing : tanks with opaque walls, running sea
water, even overhead illumination and a source of wild plankton
(Bahnw nauplii, obtained from the adults before spawning, also being
eatisfactory ).
Little success seems to have been met with in rearing clupeib othor
than herring, though A h u species have been reared in pondn in