Lower Lethal Temperature for Arapaima Arapaima gigas: Potential Implications for Culture and Establishment in Florida

Abstract

AbstractArapaima Arapaima gigas is a large, predatory, obligate air‐breathing fish native to the Amazon River basin. Aquaculture producers have identified this species as a candidate for commercial culture in Florida. For this species, a preliminary risk assessment using the Fish Invasiveness Screening Kit indicated a medium to high risk of invasiveness to parts of central and southern Florida. However, data on lower lethal temperature were not available, which was a data gap identified by the risk assessment. Lower lethal temperature is an important physiological characteristic, limiting not only the culture of tropical fishes in subtropical Florida but also the potential for establishing nonnative populations. This study is the first known experimental test of low‐temperature tolerance for Arapaima. Our findings suggest Arapaima will not survive temperatures at or below 16°C. When compared with established nonnative fishes in Florida, this species is extremely cold sensitive, similar to that of Butterfly Peacock Bass Cichla ocellaris. Although this could present challenges to producers, it might also mitigate some concerns of regulatory staff charged with managing aquatic invasive species.