Multiple-stressor interactions influence embryo development rate in the American horseshoe crab, Limulus polyphemus

Area of Science:

• Marine Biology
• Ecology
• Developmental Biology

Background:

• Fertilized horseshoe crab eggs (Limulus polyphemus) develop in nests exposed to variable abiotic conditions.
• Early embryonic development is crucial for marine invertebrates inhabiting intertidal zones.

Purpose of the Study:

• To investigate the impact of combined abiotic stressors on horseshoe crab embryonic development.
• To determine if interactions between temperature, salinity, and oxygen levels affect developmental success.

Main Methods:

• Embryos were exposed to 27 factorial combinations of temperature, salinity, and oxygen for 14 days.
• Developmental rates were monitored, and embryos were allowed to recover under control conditions.
• Growth rates were measured every two days for 1289 embryos.

Main Results:

• Isolated stressors reduced developmental success, with low salinity causing up to 72% reduction.
• Complex synergistic interactions were observed; low oxygen combined with high temperature was lethal.
• Low temperature mitigated negative effects of low salinity and low oxygen.

Conclusions:

• Abiotic stressor interactions significantly alter horseshoe crab embryonic development.
• Predicting developmental outcomes based on single stressors is insufficient due to synergistic effects.
• Understanding these interactions is vital for coastal invertebrate resilience in changing environments.