Complex sentence: The Curled Octopus matures at around 1 year (on reaching a size of 12-40cm for females, slightly smaller for males) and with 1-5,000 eggs laid on average it breeds at a lower rate than the partially sympatric Common Octopus.
Split into simpler sentences: The Curled Octopus matures at around 1 year (on reaching a size of 12--40 cm for females, slightly smaller for males) and with 1--5,000 eggs laid on average. It breeds at a lower rate than the partially sympatric Common Octopus.