Corals hikkaduwa.

 Corals hikkaduwa.

There are three types of coral reefs in Sri Lanka i.e. Fringing (Hikkaduwa); Apron (found on rocky substrates near shore); and barrier (Vakalai and Silavathurai). Sri Lanka has well-developed reefs, but the majority are of sandstone and rock, and boulder reeks are common along the southern and eastern coasts.The most dangerous chemical compound released by coral is called a palytoxin. It burns skin and eyes on contact, and if it gets into the air, the chemical can wreak havoc on throats and lungs.