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

Abstract

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.

Cephalopod ontogeny and life cycle patterns

“…The duration of development is species-specific, strongly dependent on temperature and egg size. Embryogenesis can take 10-15 days for sepiolid small eggs incubated at warmer temperatures (Nabhitabhata, 2014;Nabhitabhata and Nishiguchi, 2014) or many months to years in large-egged octopus incubated at colder temperatures (Uriarte et al, 2010;Robison et al, 2014;Khen et al, 2022). Within the optimal incubation temperature range for a given species, higher temperatures shorten the time between spawning and hatching and those outside the optimal range increase the incidence of abnormalities and death (Vidal and Boletzky, 2014).…”

“…Eledone moschata, 10.5 mm ML) and in the deep-sea [e.g. Graneledone boreopacifica, 28 mm ML (Villanueva et al, 2016); Octopus californicus, 12 mm ML (Khen et al, 2022); Grimpoteuthis sp., 13 mm ML (Shea et al, 2018)].…”