that a continual change in chemistry occurred until the larvae became 
moribund. 
In a similar study Anraku and Azeta (6) compared cultured and wild larvae 
and juveniles of the sea bream Chrysophrys major. They did not examine larvae 
less than 10 mm length, but for large specimens the cultured individuals tended 
to have a lower percentage of water, higher percentages of carbon and 
hydrogen, and a percentage nitrogen that did not differ from wild specimens 
until 20 mm length, when percentage nitrogen decreased in cultured 
individuals. Differences in food of cultured and wild specimens were the 
probable cause of differences in body chemistry. Starved individuals of sea 
bream showed effects similar to those for herring and plaice — i.e. increased 
percentage water and decreased percentages of carbon, nitrogen and hydrogen. 
Histological changes in laboratory-reared larvae are indicative of starvation. 
Recent studies indicate that these criteria could be used to recognize starving 
or poorly nourished larvae in the sea. Umeda and Ochiai (96) examined fed and 
starved yellowtail Seriola quinqueradiata larvae, Ehrlich et al (34) examined 
herring and plaice larvae, and O’Connell (72) examined northern anchovy 
larvae. In all of these studies there were some similar findings. Intestinal 
epithelial cells atrophied in starving larvae and the intestine degenerated. The 
liver also degenerated in yellowtail, plaice and northern anchovy. O’Connell 
(72) and Umeda and Ochiai (96) examined the pancreas and found that its 
condition was markedly deteriorated in starved anchovy and yellowtail larvae. 
O’Connell (72) examined several other histological characters and found that 
starved anchovy larvae also had separations of muscular fibers and little 
intermuscular tissue, as well as notochord shrinkage. Using a discriminant 
function analysis he was able to discriminate 90 percent of starving larvae from 
fed larvae when four or more good histological characters were used. Ehrlich et 
al (34) found that there were good morphological characters associated with 
the histological changes, especially in herring larvae where severe head 
shrinkage and gut shrinkage caused a decrease in the “pectoral angle”, and an 
increase in the eye height to head height ratio. Histological criteria as indicators 
of impending starvation seem excellent. They are relatively time consuming 
compared to morphometric analyses, but perhaps are more effective to 
distinguish starvation effects. 
The concentration of prey affects larval behavior. Wyatt (100) 
demonstrated that duration of plaice larvae activity (searching behavior) was 
inversely related to prey concentration, and that starving larvae increased their 
time spent searching for food. This behavior presumably is adaptive and 
increases the probability of encountering prey when it is scarce. Using vertical 
migration as an index of activity, Blaxter and Ehrlich (20) found that fewer 
herring and plaice larvae vertically migrated after periods of starvation, and 
186 
