title: Increased temperature, but not acidification, enhances fertilization and development in a tropical urchin: potential for adaptation to a tropicalized eastern Australia.
abstract: To predict the effects of global change on marine populations, it is important to measure the effects of climate stressors on performance and potential for adaptation. Adaptation depends on heritable genetic variance for stress tolerance being present in populations. We determined the effects of near-future ocean conditions on fertilization success of the sea urchin Pseudoboletia indiana. In 16 multiple dam-sire crosses, we quantified genetic variation in tolerance of warming (+3°C) and acidification (-0.3 to 0.5 pH units) at the gastrulation stage. Ocean acidification decreased fertilization across all dam-sire combinations with effects of pH significantly differing among the pairings. Decreased pH reduced the percentage of normal gastrulae with negative effects alleviated by increased temperature. Significant sire by environment interactions indicated the presence of heritable variation in tolerance of stressors at gastrulation and thus the potential for selection of resistant genotypes, which may enhance population persistence. A low genetic correlation indicated that genotypes that performed well at gastrulation in low pH did not necessarily perform well at higher temperatures. Furthermore, performance at fertilization was not necessarily a good predictor of performance at the later stage of gastrulation. Southern range edge populations of Pseudoboletia indiana may benefit from future warming with potential for extension of their distribution in south-east Australia.
authors.affiliation: School of Medical Sciences, The University of Sydney and Sydney Institute of Marine Science Sydney, NSW, Australia.
authors.forename: Shawna A
authors.initials: SA
authors.lastname: Foo
authors.affiliation: National Marine Science Centre, Southern Cross University Coffs Harbour, NSW, Australia.
authors.forename: Symon A
authors.initials: SA
authors.lastname: Dworjanyn
authors.affiliation: Faculty of Veterinary Science, The University of Sydney Sydney, NSW, Australia.
authors.forename: Mehar S
authors.initials: MS
authors.lastname: Khatkar
authors.affiliation: Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, NSW, Australia.
authors.forename: Alistair G B
authors.initials: AG
authors.lastname: Poore
authors.affiliation: Schools of Medical and Biological Sciences, The University of Sydney Sydney, NSW, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Byrne
keywords: North Carolina II; climate change; ocean acidification; quantitative genetics; sea urchin