The underwater photo taken on Oct. 4, 2019 shows a clownfish swimming around sea anemones at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)

The underwater photo taken on Oct. 4, 2019 shows a clownfish swimming around sea anemones at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)

The underwater photo taken on Oct. 4, 2019 shows fishes swimming around corals at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)

The underwater photo taken on Oct. 4, 2019 shows fishes swimming around corals at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)

The underwater photo taken on Oct. 4, 2019 shows clownfish swimming around sea anemones at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)

The underwater photo taken on Oct. 4, 2019 shows corals at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)

The underwater photo taken on Oct. 4, 2019 shows marine fishes swimming around corals at the Boundary Island Tourist Attraction in Lingshui County, South China's Hainan Province. (Xinhua)