Attempts have been made at mass cultivation of zooplankton to be used as food for fish larvae in their early stage. The present paper deals with fundamental experiments for densely populated culture of Acartia clausi.In a field survey,one population preferring a high temperature of 21-25℃ and low salinity of 10-20‰ S was found. In the present paper this is referred to as "summer form".
A high production of eggs per unit volume was attained in a high density culture (one adult per ml). Coexistence of the male had no marked effect on the egg-laying during a ten day culture. The eggs stored at 0℃, in darkened seawater (28.5‰ S) showed higher survival, and hatching rate of about 80% even after 20 days. The nauplii of summer form in high density (5,000/1) fed on Isochrysisg galbana and Monochrysis lutheri grew with small loss until the latter stage of copepodite. They were maintained at that stage in a density of 3,200/1. A favorable concentration of food algae for survival was about 5×10⁵ cells/ml until the early stage of copepodite, and after that about 10×10⁵ cells/ml with combination of Isochrysis and Monochrysis in equal density.
Dinoflagellate, Prorocenlrum minimum was also excellent food for the animals, though the filtrate of medium which they grew densely showed toxicity for the animals. The egg production and growth rate were incresed remarkably by the addition of P.minimum to the basic food algae.
During the culture period, among the chemical factors in the cultural seawater a change was notable in the ammonia concentration. It increased to about 40μg-at./l in the seawater which contained about 1×10⁵ cells/ml each of Isochrysis and Monochrysis. The nauplii could tolerate a fairly high ammonia concentration (ca. 3 mg-at./1), however, this tolerance decreased as they grew. For the adult, the lethal concentration was about 1 mg-at./l. On the other hand, the oxygen consumption averaged 0.081μl-O₂/hr/animal(2.94μl-O₂/day/animal). These results suggest that a deficiency of dissolved oxygen during the dark period greatly the growth of A. clausi in a cultual condition of high density of animal and food algae.
雑誌名
三重大学水産学部研究報告 = Bulletin of the Faculty of Fisheries, Mie University
巻
11
ページ
75 - 93
発行年
1984-10-01
ISSN
0287-5772
書誌レコードID
AN0023428X
フォーマット
application/pdf
著者版フラグ
publisher
日本十進分類法
485
その他のタイトル
Cultivation of marine copepod, Acartia Clausi GIESBRECHT - II : Fundamental experiments on mass culture
海産橈脚類, Acartia clausi GIESBRECHT の飼育 - II : 高密度飼育に関する基礎実験
AN0023428X0001109.pdf
(903.7KB)
