Contribution to the biology of the endangered Mexican fish, Zoogoneticus tequila, and suggestion for its indoor management

The endangered Mexican fish, Zoogoneticus tequila Webb & Miller, 1998, represents a new challenge for scientists: its biology, quite unknown, could perhaps explain the reason for its extremely low consistency in natural environments. An experimental setting was prepared where four pairs of young Z. tequila from the only Italian colony were bred in two different (biotope and enriched) tanks. Breeding results showed that the animals have grown and presented a positive reproductive performance, in both the environmental conditions confirming that the choice of substrata, of the vegetable layout, of food administration and of breeding of fry, resulted optimal for the indoor breeding. Aggressive behavior was extremely low and, although inter-male interactions were unstable, no injuries were observed among the animals, apart from a few episode of cannibalism towards the young. The behavior of animals in stressful situation were also recorded, namely the encounter with a male displaying enhanced sexual characters or with a predator. The behavioral responses toward the male were mainly noticed in the enriched tank, where flicks of tail and display of fins were recorded compared to the biotope. On the other hand, the predator snake Thamnophis sp. elicited an innate flight response in both the experimental conditions and in both genders. All together those results seem to encourage the breeding of Z. tequila in captive condition, although more studies on the cognitive skills of the species are needed before its reintroduction in natural environment.[...]