42 ‘mini-hotels’ installed to study lesser-known coral reef creatures . Forty-two “mini hotels” have been installed across seven underwater locations in Singapore, as part of a new research effort announced on Oct 28 that aims to help scientists better understand the different types of marine life here.  The structures, known as Autonomous Reef Monitoring Structures (Arms), are stacks of plastic plates that mimic the structure of a coral reef, providing nooks and crannies for sea creatures, including crustaceans, burrowing worms, sponges and encrusting algae, to find homes in. The units have been anchored to the seafloor with stakes at Raffles Lighthouse, Sisters’ Islands Marine Park, St John’s and Kusu islands, Pulau Semakau, and two sites near Pulau Hantu.