Projected near-future CO2 levels increase activity and alter defensive behaviours in the tropical squid Idiosepius pygmaeus

DOI

Carbon dioxide (CO2) levels projected to occur in the oceans by the end of this century cause a range of behavioural effects in fish, but whether other highly active marine organisms, such as cephalopods, are similarly affected is unknown. We tested the effects of projected future CO2 levels (626 and 956 µatm) on the behaviour of male two-toned pygmy squid, Idiosepius pygmaeus. Exposure to elevated CO2 increased the number of active individuals by 19-25% and increased movement (number of line-crosses) by nearly 3 times compared to squid at present-day CO2. Squid vigilance and defensive behaviours were also altered by elevated CO2 with >80% of individuals choosing jet escape responses over defensive arm postures in response to a visual startle stimulus, compared with 50% choosing jet escape responses at control CO2. In addition, more escape responses were chosen over threat behaviours in body pattern displays at elevated CO2 and individuals were more than twice as likely to use ink as a defence strategy at 956 µatm CO2, compared with controls. Increased activity could lead to adverse effects on energy budgets as well as increasing visibility to predators. A tendency to respond to a stimulus with escape behaviours could increase survival, but may also be energetically costly and could potentially lead to more chases by predators compared with individuals that use defensive postures. These results demonstrate that projected future ocean acidification affects the behaviours of a tropical squid species.

In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation is 2014-12-01.

Supplement to: Spady, Blake L; Watson, Sue-Ann; Chase, Tory J; Munday, Philip L (2014): Projected near-future CO2 levels increase activity and alter defensive behaviours in the tropical squid Idiosepius pygmaeus. Biology Open, 3(11), 1063-1070

Identifier
DOI https://doi.org/10.1594/PANGAEA.839886
Related Identifier https://doi.org/10.1242/bio.20149894
Related Identifier https://cran.r-project.org/package=seacarb
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.839886
Provenance
Creator Spady, Blake L ORCID logo; Watson, Sue-Ann ORCID logo; Chase, Tory J (ORCID: 0000-0002-2044-136X); Munday, Philip L ORCID logo
Publisher PANGAEA
Contributor Yang, Yan
Publication Year 2014
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 1044 data points
Discipline Earth System Research
Spatial Coverage (147.367 LON, -19.417 LAT)
Temporal Coverage Begin 2013-09-01T00:00:00Z
Temporal Coverage End 2013-10-31T00:00:00Z