Reproductive behaviours and transgenerational effets of elevated carbon dioxide in the three-spined stickleback

Chair: Martin Grosell

Josefin Sundin(1), Laura Vossen(1), Fredrik Jutfelt(2)

1 Uppsala University, Uppsala, 751 24, Sweden
2 Norwegian University of Science and Technology, Trondheim, 7491, Norway

Background
Major effects of ocean acidification on marine organisms have been projected, including behavioural disturbances in fish. However, the impact ocean acidification may have on reproduction is still largely unknown.

Methods
Courtship and mating behaviours, vital components of reproduction previously not assessed in relation to CO2, were investigated using three-spined stickleback exposed to elevated levels of CO2 (~1000 µatm). Offspring behaviour was subsequently tested 48 h and 6 days post-hatching.

Findings
No effect of CO2 was found on courtship behaviours such as zig-zag, fanning, leads to nest, number of bites at female, and no effect on latency until mating, mating duration, number of mating attempts, or in number of offspring was found. Additionally there was no effect of CO2 on offspring activity when tested 48 h post-hatching. At 6 days post hatching, however, there was an effect of elevated CO2 on offspring activity.

Conclusions
We found no effect of elevated CO2 on courtship behaviours, despite the fact that this species has proven susceptible to CO2 for other behavioural measures. In addition, offspring behaviour, when tested 48 h post-hatching, was unaffected by CO2, which is in contrast to findings on coral-reef larvae. We did find an effect of CO2 on offspring that had been incubated and subsequently tested 6 days post-hatching, but the actual difference in activity was small. Our data thus suggest reproductive behaviours in the three-spined stickleback to be tolerant to increased levels of CO2, and that any fitness consequences of the changes in offspring activity would be minor.