The enemy of my enemy is still my enemy: the biological invasion and management of Gambusia in Peninsular India

Aquatic invasive species negatively impact the native aquatic communities in many parts of the world. Every nation faces the issue of introduced species, but the efforts to manage them depend on the varying capacity and willingness to manage invasions globally. Aquatic invasive species have their own set of challenges; it is crucial to understand the invasion dynamics of these species as well as their nature of interaction with humans to devise better mitigation processes. The freshwater aquatic wealth of India is seriously threatened by pollution, flow modification, overexploitation, habitat degradation and invasive alien species. India has several globally known freshwater invasive species. This article explores the invasion dynamics, potential pathways of invasion and impacts of the introduction of two of the world’s top 100 invasive species, which remain relatively unknown in India: Gambusia affinis and Gambusia holbrooki. In the early 19th century, Gambusia species were introduced into Lalbagh Lake, Bengaluru, and eventually to other parts of the country. Gambusia is now widely distributed in the wild and in many Protected Areas, where it has become a threat to endangered amphibians, fishes and other aquatic invertebrates. This article explores the distribution of these Gambusia species in India and the drivers leading to their invasion. It also explains the obscure history of Gambusia invasion in India and the lack of awareness of its possible negative impacts. The importance of using molecular tools in taxonomy and their applications in invasion ecology are discussed. This study highlights the research gaps in invasion ecology of this genus in India and suggests scientific methods to manage these invasive species.