Before fish and other vertebrates proliferated, it was the heyday of the cephalopods. Their descendants — squid, cuttlefish, octopus, and nautilus—are still around, coping better with human dominance than many fish.

In the fourth episode of the podcast Ocean Wants, speculative writer Ingo Niermann, most recently of the book Mare Amoris, is talking to Danna Staaf, a trained marine biologist who wrote the history of the cephalopods. She speaks from her home in San Jose, California.