The behaviour and neuro‐anatomy of some developing teleost fishes

Abstract

This investigation relates the ontogenetic development of observable behaviour to theunderlying co‐ordinating and conducting systems in telecosts. It is based on a study of the eggs of seven species, fertilized artificially. The onset of behaviour was marked by the heart beat; this started in separate regions which became connected and developed a rhythm. It was followed by non‐rhythmic contractions of the body musculature, the resulting flexures becoming alternating or serial and cephalo‐caudal. Movements of the pectoral fins, jaws and opercula were first performed as part of the axial musculature of the body; later they became independent and co‐ordinated. There was an increasing tendency towards stability and efficiency in the development of response to tactile, chemical, vibrational, feeding, rotational and light stimulation.