THE BEEUVIOWR
AND PHYSIOLOOY OB HERRING AND OTHER CLUPEIDS 275
wm worked on by Ramanujam (1929) in herring and by G w p (1940)
in Clupea p&ii.
In herring the pectoral fins were present at hatching,
but the dorsal, caudal and anal fins developed between 12 and 20 m,
the vertebrae starting to develop at about 26 mm. Harder (1953) hae
shown the relative changes in the proportions of the gut, skeleton and
muscle at lengths from 6 2 4 6 mm. Lebour (1921) made a comparative
study of the relationship between myotomes, vertebrae and fins in
herring, 8prattu.a qrattus and 8ardina pilchardus, as an aid to the
identification of the larvae.
B. Feeding of larae
1. Yolk supply
The early growth and survival of 1 m a e depends partly on the yolk
supply and, therefore, on the size of the egg. In herring this varies from
ram to race and from parent to parent* ; spring and winter spawning
herring produce larger eggs (up to four times the dry weight) than
summer and autumn spawners (Rannak, 1968; Blaxter and Hempel,
1963). Larger eggs produce mainly larger larvae, but also larvae living
longer on their yolk reserves. Both these factors could be of importance to brood survival where the food supply was minimal.
2. Feeding beisaviour
On hatching, herring l m a e show much vertical movement, but
after some days more horizontal movement is observed. At the same
time searching movements for food occur. Many authors have reported
food taken by herring l m m still with yolk sacs. Food is taken by a
darting movement following an S-shaped flexing of the body (Schach,
1939; Soleim, 1942 ; Biickmann et al., 1953). The prominent eyes would
appear to indicate the importance of vision to the larvae in seeking
food. Similar feeding behaviour has been described by Breder and
Krumholz (1943) in Harengh pemmlae and Maxfield (1953) found
that the larvae of Absa sapidisdm took only zooplankton, suggesting
a predatory type of feeding. No feeding wae observed in darkness in
rearing experiments on Clupea prdhsii (Kurata, 1969) and Hentschel
(1960) and Bhattacharyya (1967) showed a cycle of feeding activity in
herring larvae caught at sea, suggesting no feeding activity by night.
while this evidence supporta the importance of vision and active
selection of food to clupeid larvae, Laaker’s (1962) observations, that
the young lmae of Surdinups mrub fed passively with gaping jaws,
the eyes at this stage being non-functional, indicate a different mechanism. However, Arthur (1966) reported that older larvae of this
Yolk sac size for larvae of e given length varied from year to yesr i n Clupea
m i ( h u k s & al., BuU. Hokkoido Reg. Fish. Rw. Lub. 25, 1-10. 1982).
19
AND PHYSIOLOOY OB HERRING AND OTHER CLUPEIDS 275
wm worked on by Ramanujam (1929) in herring and by G w p (1940)
in Clupea p&ii.
In herring the pectoral fins were present at hatching,
but the dorsal, caudal and anal fins developed between 12 and 20 m,
the vertebrae starting to develop at about 26 mm. Harder (1953) hae
shown the relative changes in the proportions of the gut, skeleton and
muscle at lengths from 6 2 4 6 mm. Lebour (1921) made a comparative
study of the relationship between myotomes, vertebrae and fins in
herring, 8prattu.a qrattus and 8ardina pilchardus, as an aid to the
identification of the larvae.
B. Feeding of larae
1. Yolk supply
The early growth and survival of 1 m a e depends partly on the yolk
supply and, therefore, on the size of the egg. In herring this varies from
ram to race and from parent to parent* ; spring and winter spawning
herring produce larger eggs (up to four times the dry weight) than
summer and autumn spawners (Rannak, 1968; Blaxter and Hempel,
1963). Larger eggs produce mainly larger larvae, but also larvae living
longer on their yolk reserves. Both these factors could be of importance to brood survival where the food supply was minimal.
2. Feeding beisaviour
On hatching, herring l m a e show much vertical movement, but
after some days more horizontal movement is observed. At the same
time searching movements for food occur. Many authors have reported
food taken by herring l m m still with yolk sacs. Food is taken by a
darting movement following an S-shaped flexing of the body (Schach,
1939; Soleim, 1942 ; Biickmann et al., 1953). The prominent eyes would
appear to indicate the importance of vision to the larvae in seeking
food. Similar feeding behaviour has been described by Breder and
Krumholz (1943) in Harengh pemmlae and Maxfield (1953) found
that the larvae of Absa sapidisdm took only zooplankton, suggesting
a predatory type of feeding. No feeding wae observed in darkness in
rearing experiments on Clupea prdhsii (Kurata, 1969) and Hentschel
(1960) and Bhattacharyya (1967) showed a cycle of feeding activity in
herring larvae caught at sea, suggesting no feeding activity by night.
while this evidence supporta the importance of vision and active
selection of food to clupeid larvae, Laaker’s (1962) observations, that
the young lmae of Surdinups mrub fed passively with gaping jaws,
the eyes at this stage being non-functional, indicate a different mechanism. However, Arthur (1966) reported that older larvae of this
Yolk sac size for larvae of e given length varied from year to yesr i n Clupea
m i ( h u k s & al., BuU. Hokkoido Reg. Fish. Rw. Lub. 25, 1-10. 1982).
19