Oh yes. I raised a clutch of baby O. mercatoris back in the 90's. Octos come in two flavors: large egged and small egged. Small egged octopuses hatch out into nearly microscopic critters that are swept away by the current, but you have a shot at rearing large egged hatchlings. They're about the size of a BB, and will eat tiny crustaceans....if you can find some. That's the whole problem: feeding a tiny but voracious predator. The amphipods that invariably inhabit our tanks are WAY too large. I started mine on copepods and brine shrimp nauplii enhanced with Selco, but as they grew their tastes changed. At around 6 weeks they started refusing everything I could obtain- peppermint shrimp larvae, brine shrimp, fiddler and red crab larvae and even a plankton trawl from the Chesapeake bay. We also attempted to rear the hatchlings of a small indonesian macropus obtained from Blue Zoo, but we couldn't get those babies to eat anything.
The mercatoris project happened long before I had a digital camera, so theer's no photography, but we did shoot a couple of the micro babies. In this one, you can see him slam into one of the baby amphipods we tried to feed him.