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Giant kelpMacrocystis pyriferaprovides the foundation for immense biodiversity on the coast of California, USA. Kelp forests can change seawater retention time, altering water chemistry, including pH and dissolved oxygen (DO), as well as the magnitude and predictability of variability in the same properties. Environmental heterogeneity across space and time could drive organismal performance and processes such as transgenerational plasticity (TGP), where parental experience modifies the offspring phenotype, potentially conferring tolerance to future environmental stress. We monitored environmental variability by deploying temperature, pH, and DO sensors inside and outside a temperate kelp forest in the Santa Barbara Channel (SBC) throughout the gametogenesis period of a key herbivore, the purple urchinStrongylocentrotus purpuratus. Over the 6 mo period, pH and temperature were slightly elevated inside the kelp forest, accompanied by more predictable, low-frequency variability relative to outside. AdultS. purpuratuswere conditioned inside and outside the kelp spanning gametogenesis. The urchins were spawned and their larvae were raised under high (1053 µatm) and lowpCO2(435 µatm) at 15°C in the laboratory to assess their physiological response to the maternal and developmental environments. Larvae raised under highpCO2were more susceptible to acute thermal stress; however, within each larval treatment, progeny from outside-conditioned mothers had a 0.4°C higher lethal temperature (LT50). Our results indicate that heterogeneity in abiotic factors associated with kelp can have transgenerational effects in the field, and interactions between factors, including temperature and pH, will impact purple urchins as local variability associated with marine heatwaves and upwelling evolves with climate change.
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This content will become publicly available on November 1, 2025
Temperature influences immune cell development and body length in purple sea urchin larvae
Anthropogenic climate change has increased the frequency and intensity of marine heatwaves that may broadly impact the health of marine invertebrates. Rising ocean temperatures lead to increases in disease prevalence in marine organisms; it is therefore critical to understand how marine heatwaves impact immune system devel- opment. The purple sea urchin (Strongylocentrotus purpuratus) is an ecologically important, broadcast-spawning, omnivore that primarily inhabits kelp forests in the northeastern Pacific Ocean. The S. purpuratus life cycle in- cludes a relatively long-lived (~2 months) planktotrophic larval stage. Larvae have a well-characterized cellular immune system that is mediated, in part, by a subset of mesenchymal cells known as pigment cells. To assess the role of environmental temperature on the development of larval immune cells, embryos were generated from adult sea urchins conditioned at 14 C. Embryos were then cultured in either ambient (14 C) or elevated (18 C) seawater. Results indicate that larvae raised in an elevated temperature were slightly larger and had more pigment cells than those raised at ambient temperature. Further, the larval phenotypes varied significantly among genetic crosses, which highlights the importance of genotype in structuring how the immune system develops in the context of the environment. Overall, these results indicate that larvae are phenotypically plastic in modulating their immune cells and body length in response to adverse developmental conditions
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- Award ID(s):
- 1831937
- PAR ID:
- 10552868
- Publisher / Repository:
- Elsevier Ltd.
- Date Published:
- Journal Name:
- Marine Environmental Research
- Volume:
- 202
- Issue:
- C
- ISSN:
- 0141-1136
- Page Range / eLocation ID:
- 106705
- Subject(s) / Keyword(s):
- Strongylocentrotus purpuratus, Marine heatwaves, Pigment cells, Body size, Immune function, Larvae
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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