title: Early development of congeneric sea urchins (Heliocidaris) with contrasting life history modes in a warming and high CO2 ocean.
abstract: The impacts of ocean change stressors - warming and acidification - on marine invertebrate development have emerged as a significant impact of global change. We investigated the response of early development to the larval stage in sympatric, congeneric sea urchins, Heliocidaris tuberculata and Heliocidaris erythrogramma with contrasting modes of development to ocean warming and acidification. Effects of these stressors were assessed by quantifying the percentage of normal development during the first 24 h post fertilization, in cross-factorial experiments that included three temperature treatments (control: 20 °C; +4: 24 °C; +6: 26 °C) and four pHNIST levels (control: 8.2; -0.4: 7.8; -0.6: 7.6; -0.8: 0.4). The experimental treatments were designed in context with present day and near-future (∼2100) conditions for the southeast Australia global warming hotspot. Temperature was the most important factor affecting development of both species causing faster progression through developmental stages as well as a decrease in the percentage of normal development. H. erythrogramma embryos were less tolerant of increased temperature than those of H. tuberculata. Acidification impaired development to the larval stage in H. tuberculata, but this was not the case for H. erythrogramma. Thus, outcomes for the planktonic life phase of the two Heliocidaris species in response to ocean warming and acidification will differ. As shown for these species, single-stressor temperature or acidification studies can be misleading with respect to determining species' vulnerability and responses to global change.
authors.affiliation: School of Medical Sciences, University of Sydney, NSW 2006, Australia. Electronic address: natasha.hardy@sydney.edu.au.
authors.forename: Natasha A
authors.initials: NA
authors.lastname: Hardy
authors.affiliation: School of Medical Sciences, University of Sydney, NSW 2006, Australia; School of Biological Sciences, University of Sydney, NSW 2006, Australia.
authors.forename: Maria
authors.initials: M
authors.lastname: Byrne
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D047329:Anthocidaris / Q000196:embryology* / Q000254:growth & development* / Q000502:physiology; D001315:Australia; D002245:Carbon Dioxide; D004625:Embryo, Nonmammalian; D057232:Global Warming; D007814:Larva / Q000254:growth & development; D008018:Life Cycle Stages; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry; D013045:Species Specificity; D013696:Temperature; D015048:Zooplankton
chemical_list: D002245:Carbon Dioxide
keywords: Climate change; Echinoid; Embryo; Larva; Life history; Ocean acidification; Ocean warming; Stress tolerance