Behavioral traits of mangrove mosquitofish (Gambusia rhizophorae) in their historic and recently expanded range in South Florida

The mangrove mosquitofish (Gambusia rhizophorae) is found in brackish ecosystems in southeast Florida (USA) and Cuba. Historical range distribution in Florida has found these fish solely in the Florida Keys and parts of Biscayne Bay. This research provides an update to the northern range limit for mangrove mosquitofish. We tested whether “personality” differed between fish in the historic and expanded portions of the range. Tests of boldness showed differences in risk tolerance and exploration between sexes, but not between fish from the historic range and expanded range. We conclude that although their range has shifted northward, bolder fish do not dominate the expansion front.