Meeting Abstract
Cyprinid fishes endemic to the Southwest have been subject to anthropogenic pressures that caused many of these species to become threatened or endangered. The foremost pressures on these fishes are habitat modification through and the introduction of non-native competitors/predators. The prevailing management strategy for many of these fishes is captive breeding/rearing and release into altered habitats. However, captive-reared fish typically suffer low survival following release. We suggest that, by combining morphological, physiological and behavioral data, management agencies can improve the survival of repatriated fishes. Recent measures of performance metrics and behaviors of fish in the Gila sp. complex in the lab and in smaller waterways have generated specific predictions about success of individuals of particular body sizes under certain conditions. For example, Gila individuals below a certain size are more likely to be consumed by non-native predators, than individuals above a particular body size; therefore, the probability that re-introduced native fishes survive after they are placed in a waterway will increase with increasing body size. Similarly, higher water flows will favor the retention of Gila sp. (based on their swimming performance); this finding suggests that controlled flooding or a return to natural hydrologic conditions would aid in native fish recovery. We conclude that understanding performance metrics associated with anatomical and physiological adaptations can allow managers to manipulate habitats to better suit native fishes. Taking a whole ecosystem management approach allows managers to not only improve the success of native fishes but return native habitats to original conditions.
