Non-native species existence and its potency to be invasive species on freshwater ecosystem in East Java Province, Indonesia

The introduction of non-native species that have been carried out so far has raised several diverse opinions about the resulting impacts, either positive or negative. As one of the leading commodities in aquaculture, the significant impact of the culture of common carp species (Cyprinus carpio) has been felt by the community. That kind of fish has dominated for both consumption and ornamental fish production in East Java. This type of fish is considered equivalent to other native fish in this region, such as tawes (Puntius javanicus), catfish (Clarias batracus), and gourami (Ospronemus gouramy). However, the problem is if the non-native fish become invasive species in the open waters. When the spread of the non-native fish is out of control, it is feared will break down the food chain and community structure of other native fishes. As Arapaima gigas, the carnivore fish that are not native fish of Indonesia, which have found along the Brantas River, East Java, Indonesia. Rigorous precautions and regulations are needed so that introduced species become species that do not endanger their new habitat by considering ecological, economic, and other impacts. The study of genetic diversity and native species is essential to be done so that the database baseline is accurate and valid.