Abstract
The arginine phosphate content was measured following fertilization of sea-urchin [Hemicentrotus pulcherrimus, Anthocidaris crassispina and Pseudocentrotus depressus] eggs and starfish [Asterina pectinifera] oocytes. In sea-urchin eggs, a rise in arginine phosphate level occurred within 2 min after insemination; this was not accompanied by any detectable alteration in the level of ATP. The level in starfish oocytes did not change on fertilization.