THE BEHAVIOUR AND PHYSIOLOGY OF HERRING AND OTHER CLUPEIDS 307
depending on its position in relation to the cod, and the angle of its
approach. Loukashkin and Grant (1959) observed the effect of the
kelp bass Paralabrax clathratos on Sardinops caeru2ea in aquaria and
found little agitation among the sardines, none being taken by the
predator. Apart from these aquarium studies, observations have been
reported at aea on the effect of predators on shoals (see Section VI, Q).
3. Disease and parasites
It is not proposed to deal in any detail with this problem due to the
difficulty of covering the literature. Disems of herring due to fungi,
bacteria and parasites have been described by Sindermann and other
workers (see Scattergood, 1957). Reports of mass mortality of clupeids
are uncommon, though Sindermann (1956) described a heavy mortality
of herring in the Gulf of St. Lawrence due to Ichthyosporidium infection.
The distribution of parasites may vary geographically in herring
populations, for instance, Ichthyosporidium hofari, Kudoa clupeidae,
larval cestodes and nematodes, and the trematode Brmhyphallw
crenatwr, in herring of the St. Lawrence and Gulf of Maine (Sindermann,
1967).
G. Cmposition of the t~ssuw
1 . General
The clupeids, and especially the herring, have been extensively
analysed chemically, mainly to provide information on the quality of
the fish as a marketable product. As Love’s (1957) review points out,
analytical figures vary enormously with age, sex, season and stock of
fish. Unfortunately there are relatively few analyses aimed at elucidating the biological significance of the subfltanccs mea~urctd.
2. Fat and water
The most variable constituent i H the hody fat,, doalt, with it, IL
previous section. The inverfle linear relationship which cxiHtH hctwccn
fat and water content (Brandes and Dietrich, 1953b) in the herring, and
reported in other clupeids, is in fact an artificial relationship, apparcnt
because most results have been expressed on a percentage (or other
proportional) basis. An absolute fall in fat undoubtedly occurs, the
percentage of other substances thus rises, although their absolute values
do not. As Hickling (1946) pointed out for Sardina pilchardw the water
and “ a s h ” provided the stable framework of the fish body. The
herring, Saydim pilchardua and Sp.rattw sprattus draw to a small extent
on protein reserves during times of starvation and gonad maturation,
but protein loss makes, only a small contribution to any total weight
lass. Changes in intracellular lipids would lead to biologically significant
21
depending on its position in relation to the cod, and the angle of its
approach. Loukashkin and Grant (1959) observed the effect of the
kelp bass Paralabrax clathratos on Sardinops caeru2ea in aquaria and
found little agitation among the sardines, none being taken by the
predator. Apart from these aquarium studies, observations have been
reported at aea on the effect of predators on shoals (see Section VI, Q).
3. Disease and parasites
It is not proposed to deal in any detail with this problem due to the
difficulty of covering the literature. Disems of herring due to fungi,
bacteria and parasites have been described by Sindermann and other
workers (see Scattergood, 1957). Reports of mass mortality of clupeids
are uncommon, though Sindermann (1956) described a heavy mortality
of herring in the Gulf of St. Lawrence due to Ichthyosporidium infection.
The distribution of parasites may vary geographically in herring
populations, for instance, Ichthyosporidium hofari, Kudoa clupeidae,
larval cestodes and nematodes, and the trematode Brmhyphallw
crenatwr, in herring of the St. Lawrence and Gulf of Maine (Sindermann,
1967).
G. Cmposition of the t~ssuw
1 . General
The clupeids, and especially the herring, have been extensively
analysed chemically, mainly to provide information on the quality of
the fish as a marketable product. As Love’s (1957) review points out,
analytical figures vary enormously with age, sex, season and stock of
fish. Unfortunately there are relatively few analyses aimed at elucidating the biological significance of the subfltanccs mea~urctd.
2. Fat and water
The most variable constituent i H the hody fat,, doalt, with it, IL
previous section. The inverfle linear relationship which cxiHtH hctwccn
fat and water content (Brandes and Dietrich, 1953b) in the herring, and
reported in other clupeids, is in fact an artificial relationship, apparcnt
because most results have been expressed on a percentage (or other
proportional) basis. An absolute fall in fat undoubtedly occurs, the
percentage of other substances thus rises, although their absolute values
do not. As Hickling (1946) pointed out for Sardina pilchardw the water
and “ a s h ” provided the stable framework of the fish body. The
herring, Saydim pilchardua and Sp.rattw sprattus draw to a small extent
on protein reserves during times of starvation and gonad maturation,
but protein loss makes, only a small contribution to any total weight
lass. Changes in intracellular lipids would lead to biologically significant
21