A review of the biology of Gambusia affinis and G. holbrooki.

摘要

The Eastern and Western Gambusia (i.e., Gambusia holbrooki and G. affinis, respectively) are considered together here because these 2 fish species are very closely related, similar in appearance, similar in biology and often confused. Widely divergent attitudes have developed with regard to these fish with some viewing them as being highly beneficial to humans through controlling mosquitoes and the diseases they harbour, and others expressing concern about the negative impacts that these fish may have on other species with which they interact. Because of the widespread distribution, high levels of abundance, ease of capture and captive maintenance, and divergent attitudes, a very large and diffuse literature has developed with regard to these species. In fact, few fish species have been studied as much as or more than these 2 species combined. There has, however, been no comprehensive review of their biology published to date. As it is not possible to provide a comprehensive review of Gambusia biology in one reasonably sized document, this paper reviews their biology at the level of species and individual, including aspects on morphology, age/sex categories, taxonomy, hybridization and subspecific variation, habitat preference, physiology, growth and development, reproduction, courtship and mating, feeding behaviour and nutrition, behaviour, physical and chemical tolerances, and dispersal, movement patterns and orientation. As would be expected of such widespread and abundant species, G. affinis and G. holbrooki are clearly very tolerant, adaptable and variable in their biology, at both individual and population levels. Both individuals and populations can tolerate, and often thrive within, a wide range of conditions and the abilities of individuals to do this are enhanced if they have time to acclimate to any changes. Populations can adapt through genetic or evolutionary changes in response to conditions that vary in space or time, and there is significant genetic variation within and between populations..