The usual suspects ………..in every house reef in Maldives
The rainbow parrot fish. Largely responsible for the fine white sand of many tropical coral islands today. While breaking of chunks of coral and rocky substrates for algae they grind up the coral rock and excrete the same as a fine sand which have over the thousands of years helped create the small islands and sandy beaches of many sandy islands like Maldives. One parrot fish can produce up to 90kgs (198 pounds) of sand each year !