[Duration of the mitotic cycle at the period of synchronous cleavage division (t0) in the starfish Asterina pectinifera (Müller et Troschel)].

The duration of a single division (tau 0) in a period of synchronous cleavage, time of development before the start of cleavage, and rotation, hatching and gastrulation stages in A. pectinifera at different temperatures were estimated. The range of temperatures optimal for embryonic and early larval development of the starfish was determined.