Bacteria in Experiments on rearing Oyster Larvæ

Abstract

THE larvæ of many species of marine invertebrates have proved difficult to rear in the laboratory; the proper control of many factors is required, including food, pH, temperature and stirring. In particular, considerable attention has been given to the requirements of the larvæ of commercial species of lamelli-branchs, especially oysters^1–4. In such work, which has involved long series of rearing experiments, it has been a common experience of workers (in Great Britain and in the United States) that some batches of larvæ fail to develop properly although the conditions provided have been apparently suitable. Some authors have ascribed this result to either the presence or absence of organic substances in the sea water, implying that such substances are either toxic or essential to the proper development of the larvæ. This view has been supported by the work of Wilson⁵ at Plymouth, which has suggested that different natural waters differ in their value as media for developing Echinus larvæ.