Culture, trade and establishment of Polypterus senegalus in Indonesia with first record of wild populations

Abstract

The African grey bichir Polypterus senegalus is a popular ornamental fish in Indonesia. Pet trade with this species is increasing, and aquaculture production is well established. Here we present a detailed market survey and volume of domestic trade, export and import between January 2018 and February 2021. Climate similarity between the native range of P. senegalus and Indonesia was analysed by the MaxEnt algorithm. A significant number of areas of numerous Indonesian islands were identified as suitable for survival and establishment of this fish. This was confirmed by the records of 3 likely established populations in rivers in Java and Sumatra, where both wild type and albino juveniles were captured. The occurrence of more feral populations was suggested by local fishermen in Kalimantan, Java, and Lombok islands; however, verification via future field trips is required. The culture of P. senegalus is unregulated in Indonesia, and the potential risk of establishment of this predatory fish and its potential spread in this Southeast Asian country is alarming for wildlife managers. Although a total ban seems the best solution, an alternative risk mitigation strategy with minimal negative effects on the socio-economic situation in local communities is more feasible. The albino phenotype of P. senegalus is probably less of a risk because of its easier detection by predators, higher sensitivity to disease and stress, and disrupted social behaviour. Since albinos are popular in Indonesia, replacing the wild phenotype with this potentially less invasive phenotype could be a recommendation after experimental confirmation of the lower invasiveness of albinos.