The effects of imidacloprid and polyester microfibers on the larval development of the endangered sunflower star.

This article investigates the effects of the neonicotinoid insecticide imidacloprid and polyester microfibers on the larval development of the endangered sunflower star, *Pycnopodia helianthoides*. Larvae were exposed to environmentally relevant concentrations of imidacloprid (10 ng/L) and polyester microfibers (25 fibers/L), individually and combined, revealing that imidacloprid caused stomach malformations in 10% of larvae and increased early mortality, while all treatments led to increased larval lengths compared to controls. Additionally, imidacloprid exposure accelerated larval settlement in the presence of adult biofilm, suggesting sublethal effects on development and behavior. The study highlights the need for further research on contaminant impacts during reintroduction efforts and the importance of assessing pesticide effects on non-target marine invertebrates, particularly endangered species like *P. helianthoides*.