Life-history traits linked to invasion: Reproduction and larval dynamics of an invasive snapping shrimp at the southernmost coast of Europe

Life-history traits such as reproductive potential and larval dynamics provide valuable insights into the establishment of non-native species, yet information on these traits is often scarce because of the difficulty of obtaining reproductive and larval data in both native and introduced ranges. The recent occurrence of the tropical snapping shrimp Alpheus cf . crassimanus in southwestern Spanish saltmarshes provides an opportunity to characterize its reproductive ecology in the introduced range. Using seasonal data collected over a single annual cycle, we examined variation in fecundity, egg size, female size, and larval occurrence of A. cf . crassimanus . Fecundity varied seasonally, peaking in summer, and increased with female size. Egg size was negatively correlated with fecundity, a pattern consistent with life-history strategies described for r-selected species. Ovigerous female density was highest in summer and spring and preceded peaks in larval density. Together, these results provide baseline information on the reproductive ecology and seasonal larval occurrence of A. cf . crassimanus in its introduced range. They suggest that high reproductive output and seasonal reproductive activity may contribute to its establishment, while highlighting the need for longer-term studies to evaluate the environmental drivers and broader ecological implications of these patterns.