Abundance, Distribution, and Genetic Variation of the Non-Native Red Claw Crayfish (Cherax quadricarinatus) on the Island of Puerto Rico

Cherax quadricarinatus is a tropical freshwater crayfish endemic to Northern Australia and was introduced to Northeastern Puerto Rico in 1997 for experimental purposes in aquaculture. In 1998 C. quadricarinatus was released, expanding its range through established populations in several reservoirs around Puerto Rico. Subsequently, species introductions can have a multitude of effects on genetic diversity. In this study we assessed distribution, abundance and genetic variation of introduced crayfish populations to test the prediction that high diversity is a result of independent gene flow from multiple introductions. A total of 158 crayfish were caught with a 75:69 reproductive female to reproductive male sex ratio. Crayfish were present in 4 out of the 6 reservoirs sampled. A Catch-Per-Unit-Effort approach (the number of individuals per trapnight) was calculated as an estimate of relative abundance for Cidra, Carite, and Guajataca reservoirs with a CPUE of 2.20, 0.361, 1.033, respectively. Genetic diversity among populations will be quantified using nine highly variable microsatellite loci. Consequently, high genetic variability will significantly contribute to the success of a non-native species on the island of Puerto Rico