First known observations of brooding, development, and hatching of fertilized eggs for the North Pacific bigeye...

The North Pacific bigeye octopus, Octopus californicus (Berry, 1911) is a cold-water, deep-sea octopod. Little is known about their biology due to difficulty accessing their natural habitat and obtaining live specimens. Although they are a frequent bycatch product in commercial bottom trawl fisheries, individuals of this species have rarely been raised in captivity and their embryonic development has not yet been documented. Considering these limitations, we were fortunate to have witnessed this process leading to successful hatching in an aquarium setting. Here, we present a brief observational account of the first-known record of brooding, development, and hatching of fertilized eggs for O. californicus. The incubation time was a maximum of 10 months at a temperature between 8-10°C and embryos hatched over a period of 2.5 months. While more detailed research is needed, this preliminary information contributes to our limited knowledge of this species and supports life history theories of prolonged embryonic development under colder temperatures.