Introduction

In recent months, several regions in India, including Andhra Pradesh, Odisha, and Punjab, have resorted to releasing mosquitofish into local water bodies as a means to combat mosquito-borne diseases.
While this approach aims to address a pressing public health concern, it brings to light ecological challenges associated with the introduction of mosquitofish.

Understanding Mosquitofish

Biological Control of Mosquitoes: Mosquitofish, particularly Gambusia affinis and Gambusia holbrooki, were introduced in freshwater ecosystems in the 1960s as an eco-friendly alternative to chemical pesticides for mosquito control.
Widespread Distribution: Originally native to the U.S., these fish have become global inhabitants due to their adaptability and tolerance to environmental fluctuations.
Unintended Consequences: Despite good intentions, the proliferation of mosquitofish has led to detrimental ecological and environmental effects.

Early Introduction: Gambusia was first introduced in India in 1928 during British rule as a measure to combat malaria.
Government and Non-Governmental Involvement: Various governmental organizations, such as the Indian Council of Medical Research (ICMR) and the National Institute of Malaria Research (NIMR), as well as local municipal corporations and health departments, were entrusted with introducing mosquitofish.
Widespread Distribution: Gambusia species are now established in multiple habitats across India.

Invasive Alien Species: Mosquitofish are among the hundred most detrimental invasive alien species worldwide, leading to the displacement and extinction of native fauna.
Threat to Biodiversity: They exhibit voracious feeding habits and aggressive behavior, posing a threat to native fish, amphibians, and freshwater communities.
Global Examples: Studies in Australia, New Zealand, and India have shown the harmful consequences of Gambusia presence, including the decline of endemic species and predation on native fish and frogs.

WHO Recommendations: The World Health Organization stopped recommending Gambusia as a mosquito control agent in 1982.
Government Recognition: In 2018, the National Biodiversity Authority of the Government of India designated G. affinis and G. holbrooki as invasive alien species.
Local Solutions: Collaborative efforts between mosquito biologists, entomologists, invasion ecologists, and fish taxonomists can identify native fish species capable of mosquito control.
River Basin Approach: Authorities can compile lists of native fish species in each river basin that are effective in controlling mosquito larvae, offering an eco-friendly alternative to invasive species.

The introduction of mosquitofish in India, once intended to combat mosquito-borne diseases, has led to ecological challenges and the disruption of native ecosystems.
To mitigate the adverse effects and protect indigenous aquatic biodiversity, it is essential to discontinue the use of Gambusia and instead explore sustainable alternatives rooted in local solutions.
By adopting a river basin approach and collaborating across disciplines, India can strike a balance between mosquito control and environmental preservation.