developing larvae

I'm hoping someone who knows a lot about the evolution of the Nautilus will help me with this question. So as far as I'm aware, the ancestral number for all cephalopod limbs is ten and nautiloids had gained more (up to ninety). The thing I'm wondering is how and why, mainly the how part. Did the...

Female Larger Pacific Striped Octpus are interoparous laying eggs over several months. Eggs are attached to the walls of the den - usually a shell. Females care for their eggs, but unlike most octopuses continue to hunt and mate while brooding. Eggs are small, about 3 mm - the size of mom's eye!