Import, trade and culture of non-native ornamental crayfish in Java, Indonesia

The pet trade is known to be one of the main sources of invasive species including freshwater crayfish, which cause socio-economic losses and negative impacts on native biota in many regions where introduced. Indonesia was identified as the leading supplier of ornamental crayfish globally but the local market has been neglected even though certain non-native species were reported previously. Based on the survey of pathways and culture of ornamental crayfish in Java, six non-native species were recorded: Cherax destructor, C. quadricarinatus, C. peknyi, C. snowden, C. warsamsonicus, and Procambarus clarkii. The latter species originates from North America and serves as a vector of crayfish plague, i.e. a disease lethal for non-North American crayfish species. Crayfish are cultured both in outdoor and indoor facilities as well as in natural lakes and reservoirs. Harvested crayfish are transported via numerous routes across most of the island of Java. It is obvious that the local market for ornamental crayfish is well-developed and Jakarta, Surabaya and Yogyakarta were identified as hotspots of this trade. Further monitoring, detailed analysis of the market and a ban of high-risk P. clarkii are recommended to improve management and existing legislation.