Journal of the Faculty of Fisheries and Animal Husbandry, Hiroshima University Volume 12 Issue 2
1973-12-20 発行

Blood Properties of Cultured Yellow Tail, Seriola quinqueradiata Temminck and Schlegel : I Effect of Disease Caused by Anchovy, Engraulis japonica HOUTTUYN, as Diet

養殖ハマチの血液性状 : I. カタクチイワシ投餌の影響
Nanba, Kenji
Nakagawa, Heisuke
Murachi, Shiro
Kayama, Mitsu
Nakamura, Tatsuo
Investigations have been carried out in view of verifying the effects of the disease caused by anchovy, Engraulis japonica, as a diet, on the blood properties of cultured yellow tail, Seriola quinqueradiata.

Yearling yellow tail were fed for 50 days with two different diets, i.e. one was anchovy as an experimental diet and the other was sand launce, Ammodytes personatus, as control.

The results can be summarized as follows:
i) Fish fed on anchovy showed a loss of appetite and a retarding growth after about 10 days; exhibited abnormal swimming patterns, change of body color, and atrophy of the liver after about 20 days; mortality mounted to about 50% at the end of 50 days while that of control group remained at 5% level. The dead fish showed a remarkable change of body color, severe atrophy of the liver, and protrusion of the eye-balls. The liver weight of fish fed on anchovy was smaller than that of control fish.
ii) Hemoglobin concentration and hematocrit value did not differ significantly in both groups.
iii) Total plasma cholesterol concentration of fish fed on anchovy stayed almost unchanged with their growth, while those of the controls increased.
iv) Total plasma protein and A/G ratio of fish fed on anchovy decreased with the progress of the disease. Those decreases both in total plasma protein concentration and A/G ratio indicated a decrease of globulin fraction. A/G ratio of control group, however, decreased more noticeably.
v) Cellulose acetate electrophoresis separated the plasma protein of yellow tail into six major fractions. The electrophoretic pattern varied especially on plasma fraction III.
vi) The main lipoprotein fraction agreed to the plasma fraction IV. Fish fed on anchovy freqnently lacked a lipoprotein corresponding to plasma fraction IV.
vii) The considerable decrease of plasma lipid of the fish fed on anchovy was judged to be due to a lower degree of staining intensity for lipid and to the decrement of total plasma cholesterol concentration.
viii) In the lipid classes of fish fed on anchovy, low proportions of triglycerides and phospholipids and high proportions of wax esters were noticed.