DNA barcoding of a stowaway reef coral in the international aquarium trade results in a new distribution record

Dead corals and limestone boulders that act as substrate for live specimens of marine invertebrates and algae are sold as 'live rock' in the international aquarium trade. During a customs inspection of an airfreight shipment of 'live rock' at Schiphol Airport (Netherlands), 450 boulders imported from Indonesia were checked for the presence of undeclared organisms. During unpacking, about 50% of the boulders appeared to have small stony corals attached to them. Some of these corals belonged to a species unknown from Indonesia. Mitochondrial COI and nuclear ITS markers revealed 100% and 99.3% match with Polycyathus chaishanensis Lin et al., 2012, a species reported from tidal pools in Taiwan. This new distribution record suggests that despite their easy access, intertidal and shallow subtidal reef coral assemblages (< 1 m depth) may still be underexplored.