Using genomics and morphometrics to monitor data-poor and commercially exploited octopod populations

Abstract

Over 150 species of benthic octopods have been described within the ‘catch-all’ Octopus genus (Family: Octopodidae) and yet, many Octopus species harvested by fisheries remain unidentified to species-level due to a lack of distinguishing traits. Within species, there is also limited information on how populations differ genetically and the level of connectivity between populations. Therefore, we sampled octopods from commercial fisheries in southeast Australia, in order to identify the species, examine the phylogeographic relationships among species and the level of population genetic structuring within species, as well as to look for any adaptive genetic variation. The mitochondrial gene, cytochrome oxidase subunit III (COIII), was sequenced in 346 octopods along with single nucleotide polymorphisms using double digest restriction site-associated DNA sequencing (ddRADseq). Morphometric traits were also measured in mature specimens. The southern keeled octopus (‘Octopus’berrima) and pale octopus (‘Octopus’pallidus) were identified using COIII data. For ‘Octopus’berrima, we found that some populations whilst being morphologically similar were genetically distinct. In contrast, ‘Octopus’pallidus populations were both morphologically and genetically distinct across the studied regions. Our results provide key information to better inform conservation and management decisions for developing octopod fisheries in southeast Australia and highlight the importance of genomics tools in the conservation management of commercially and recreationally important species.

Projected ocean temperatures impair key proteins used in vision of octopus hatchlings

“…As voracious predators that occupy a broad trophic niche, the impaired survival of such an ecologically significant taxon can alter ecosystem functioning by influencing food‐web dynamics. Not only are octopuses facing fishing pressure (Hua, Thomson, et al., 2023), but the predicted negative impacts of global warming on octopus survival from our study also suggest that they are under additional environmental pressure as they face an uncertain future in a changing climate. In addition, we have shown the usefulness of quantitative proteomics in identifying and quantifying changes in protein expression levels and thereby assessing the adaptability or vulnerability of organisms to environmental stressors.…”

“…Not only are octopuses facing fishing pressure (Hua, Thomson, et al, 2023), but the predicted negative impacts of global warming on octopus survival from our study also suggest that they are to thermal stress (Hua, Young, et al, 2023). A mechanistic understanding of how species would perform under future warming will be critical in developing effective mitigation strategies to help protect vulnerable species and ecosystems.…”