Detail of an encrusting sponge growing on a coral reef in Komodo National Park, Indonesia.

Detail of an encrusting sponge growing in Lembeh Strait, Indonesia.

Detail of an encrusting sponge growing on a reef in Komodo National Park, Indonesia. This tropical region in Indonesia is known for its spectacular coral reefs and high marine biodiversity.

Encrusting sponges, soft corals, and other invertabrates living on pilings on Arborek Reef, Raja Ampa, Indonesia, Southeast Asia, Asia

Encrusting sponges, soft corals, and other invertabrates living on pilings on Arborek Reef, Raja Ampa, Indonesia, Southeast Asia, Asia

Encrusting sponges, soft corals, and other invertabrates living on pilings on Arborek Reef, Raja Ampa, Indonesia, Southeast Asia, Asia

Giant clam (Tridacna maxima) with encrusting sponge, Rongelap, Marshall Islands, Pacific

Diver and encrusting sponges and ascidians, St. Peter and St. Paul's rocks, Brazil, South America

Encrusting sponges and ascidians, St. Peter and St. Paul's rocks, Brazil, South America

Red encrusting sponge (Clathria sp.), Pohnpei, Federated States of Micronesia, Caroline Islands, Micronesia, Pacific Ocean, Pacific

Ascidian next to yellow and red encrusting sponges, West Escarceo, Puerto Galera, Mindoro, Philippines, Southeast Asia, Asia

Colorful encrusting sponges, Ilha Escalvada, Guarapari, Espirito Santo, Brazil, South America

Colorful encrusting sponges and corals cover the rock formations at Pedras Secas, Fernando de Noronha, Pernambuco, Brazil, South America

Brown encrusting sponges (Chondrosia collectrix) and yellow encrusting sponges (Didiscus oxeata), St. Peter and St. Paul's rocks, Brazil, South America

Colorful encrusting sponges and corals cover the rock formations at Pedras Secas, Fernando de Noronha, Pernambuco, Brazil, South America

Comet star (Ophidiaster guildingii) and encrusting red sponges, Ilha Escalvada, Guarapari, Espirito Santo, Brazil, South America

Encrusting sponge, Clathria sp, detail. This genus takes the shape of whatever it begins growing on. Buyat Bay, North Sulawesi, Indonesia, Pacific Ocean.

Colorful encrusting sponges, Ilha Escalvada, Guarapari, Espirito Santo, Brazil, South America

Colorful encrusting sponges and corals cover the rock formations at Pedras Secas, Fernando de Noronha, Pernambuco, Brazil, South America

Encrusting red sponge, Ilha Escalvada, Guarapari, Espirito Santo, Brazil, South America

Colorful encrusting sponges and corals cover the rock formations at Pedras Secas, Fernando de Noronha, Pernambuco, Brazil, South America

Colorful encrusting sponges and corals cover the rock formations at Pedras Secas, Fernando de Noronha, Pernambuco, Brazil, South America

Rock covered with encrusting sponges, Fernando de Noronha, Brazil, South America

This red encrusting sponge (Clathria sp.) is the most common of this family found in Hawaii. Here it has covered the calcium carbonate-producing seaweed, Halimeda kanaloana, Hawaii, United States of America

Finger Soft Coral between Encrusting Sponge, Alcyonium palmatum, Spirastrella cunctatrix, La Vaca, Medes Islands, Costa Brava, Mediterranean Sea, Spain