Quantifying and Predicting the Spread of Established Non-Native Fishes in Peninsular Florida, USA

The spread of non-native species plays a substantial role in the designation of a species as invasive, yet the determination and measurement of non-native-species spread is challenging, particularly for fishes, which are limited by aquatic connectivity. Spread has been quantified for fishes in a variety of ways and exact methods vary by region and taxonomic group. In this study, we quantified fish spread in peninsular Florida and used life history traits to understand what factors contribute to the rate at which fish species spread. Using a variety of statistical analyses, we found that fast spreaders in peninsular Florida tend to have a larger body size, narrow diet, shorter time to hatch, greater salinity tolerance, and higher fecundity. However, some variables like parental care, egg diameter, and reproductive guild were the same or very similar across all established species that were included in the analyses. Predicting whether an established species will spread quickly or slowly in Florida may be more challenging than predicting whether an introduced fish species will establish, yet there is support across regions for the use of life history traits in the risk assessment process.