Given the task definition and input, reply with output. In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.

Passage: The Chinese giant salamander (Andrias davidianus) is one of the largest salamanders and one of the largest amphibians in the world. It is fully aquatic and is endemic to rocky mountain streams and lakes in the Yangtze river basin of central China. Either it or a close relative has been introduced to Kyoto Prefecture in Japan and Taiwan. It is considered critically endangered in the wild due to habitat loss, pollution, and overcollection, as it is considered a delicacy and used in traditional Chinese medicine. On farms in central China, it is extensively farmed and sometimes bred, although many of the salamanders on the farms are caught in the wild. It has been listed as one of the top-10 "focal species" in 2008 by the Evolutionarily Distinct and Globally Endangered project. The Chinese giant salamander is considered to be a "living fossil". Although protected under Chinese law and CITES Appendix I, the wild population has declined by more than an estimated 80% since the 1950s. Although traditionally recognized as one of two living species of Andrias salamander in Asia, the other being the Japanese giant salamander, evidence indicates that the Chinese giant salamander may be composed of at least five cryptic species, further compounding each individual species' endangerment.
Link Information: The Japanese giant salamander was first catalogued by Europeans when the resident physician of Dejima Island in Nagasaki, Philipp Franz von Siebold, captured an individual and shipped it back to Leiden in the Netherlands, in the 1820s. Answer: in the 1820s
When was the Japanese giant salamander first discovered?