Effects of Petroleum Microorganisms, as Diet, upon the Growth Rate and Blood Properties of Sea Bream, Chrysophrys major Temminck & Schlegel

石油酵母30%,フィッシュミール50%を含む飼料(試験飼料)とフィッシュミール70%を含む飼料(対照飼料)とを,マダイに投与して,105日間の飼育結果を比較した.成長ならびに餌料効果の面では,両者に差異が認められなかったが,飼育試験終了時における試験飼料投与群の血液性状は対照飼料投与群にくらべ,一般に血漿グルコース濃度はやや高く,血色素量およびヘマトクリット値は僅かに低く,さらに血漿中アルカリ性フォスファターゼ活性及び血漿総コレステロール濃度の著しい低下が認められた.

Investigations have been carried out with a view to see the effects of the introduction of petroleum microorganisms in the diet of cultivated marine fishes. Sea bream, Chrysophrys major, was used as the experimental fish. Studies were made by comparing the growth rates and blood properties of fish under two types of feeding i.e. one when fed on a diet containing petroleum microorganisms and the other when fed on a diet of fish meal alone. Results can be summarized as follows:
i) The mortality rate remains almost the same.
ii) The body size and growth rate do not differ significantly.
iii) Anatomical observations do not reveal any change in the morphological structure of the visceral organs.
iv) Hemoglobin concentration, hematocrit values, and plasma glucose concentration remain almost the same.
v) Cholesterol concentration and alkaline phosphatase activity in plasma are lowered by the introduction of petroleum microorganisms in the diet. This lowering is significant especially in the latter case.

Physiological mechanisms causing such differences in the blood properties, yet remain to be understood.