Biodiversityprovides welfare system for people and communities. Most of the word’s biodiversity exist in economically poor countries, and provides the poor with opportunities for their livelihood. Biodiversity is traded off very rapidly for immediate gains.
Habitat destruction is known as the number one cause of biodiversity loss. Invasion of organisms, called bioinvasion, is the second most important threat to biodiversity. Alien species, after becoming locally dominant, invade natural communities and are referred as invasive species.Invasive Alien Species (IAS), after becoming established in natural, or semi natural ecosystems, serves as an agent of change, and threatens biological diversity.
IAS are characterized by their ability of unrestrained vegetative spread, prolific seed production along with seed dispersal, successful colonization, and competing with the native biota ,including decline ,or elimination of native species. IAS are non-native and may cause harm, or adversely affect human health, and biodiversity. IAS are reported to contribute in about 40% of all animal extinction.
Non-native fishes are introduced around the world for improving commercial fisheries, and as biocontrol agent of mosquito. Introduced fish often alter the water quality, and cause the extinction of native fish species by predation, or resource competition.
The article 8(h) of CBD suggests measures to “prevent the introduction, and control or even eradicate those alien species, which threaten ecosystems, habitats, or species’.
J.D. Marcus Knight in his review published in journal of Threatened taxa in 2010 argues that invasive alien fish species have taken advantage of the aquarium trade, and are emerging as the most important threat to fragile aquatic ecosystems. He listed nine fish species as invasive ornamental which are Guppy, Platy, Swordtail, Three-spot Gourami, Giant Gourami, Flower horn, Red Piranha, and Gold Fish.
One third of the aquatic species on the IUCN Species Specialist Group’s list of the 100 worst invasive species are from aquarium, or ornamental release as reported by Lowe and others in the year 2000.
Stringent measures are required to monitor the aquarium fish trade, and accidental release of exotic fish species must be prevented