Laboratory experiments on some factors affecting the survival of marine teleost larvae

Abstract

There has been remarkably little precise experimental work upon the conditions necessary for the successful rearing of marine larval fish. The experiments described here were therefore undertaken as part of a study of the biology of the common shore fish Blennius pholis L. and Centronotus gunnellus (L.) (Qasim, 1956 a, b, 1957 a, b). A preliminary report of the initial experiments (Qasim, 1955) has already revealed the necessity of providing suitable conditions, not only of food, but of diurnal changes in illumination. The present account describes another series of experiments subsequently undertaken to investigate the influence of food, light, water agitation and temperature on the survival of larvae of the two species. In addition to these factors, there are observations on the ' gas disease', noticed in various species by many authors and attributed by some to supersaturation of water with gases (Soleim, 1940 ; Dannevig & Dannevig, 1950 ; Henly, 1952).