Anomastraea

Lore & Background

The crisp pillow coral consists of soft, little polyps assisted by small tentacles that guide food in the water to the coral's mouth. The polyps discharge a skeleton made of calcium carbonate known as corallite, which participates in the formation of coral reefs. The corallites establish an uneven honey-comb pattern. As a member of the family Siderastreidae, it is zooxanthellate, living in harmony with zooxanthellae, a unicellular algae that aids the coral in growth and survival. The coral protects the algae with its tissue while the algae helps the host with energy and nutrients, as well as removing metabolic waste. The crisp pillow coral is restricted to staying in shallow waters where the zooxanthellae can execute photosynthesis.

The crisp pillow coral is found on the East African coast, the southern area of the Red Sea, the Gulf of Aden, north and southwestern Indian Ocean, and the Persian Gulf. It is not found in the Chagos Archipelago. It is also known in small areas around Madagascar and islands near it. It is populated in shallow and sandy, tropical coral reef systems, at the base of the reefs and intertidal pools, living in turbid water usually to about 20 m in depth.

Reader's Guide

The crisp pillow coral is threatened to extinction with a decreasing population. The principal threat is rising sea temperature due to global warming and increasing climate, which expels the zooxanthellae from the coral, leaving it weak and prone to many diseases. Climate change is also expected to increase ocean acidification and destructive weather such as storms that destroy coral reefs. The crown-of-thorns starfish is a voracious predator of coral reefs; since the 1970s, an increasing population of this starfish has broken out, consuming more corals. Human activity has caused this outbreak: overfishing of unprotected reefs may deplete predators of the starfish, such as the humphead wrasse, and the triton snail is being collected for its valuable shell. Nutrients from agriculture wash into oceans, causing phytoplankton population increases that provide more food for starfish larvae. Other causes of decline include pollution, destructive fishing practices, human activity, and invasive species. The crisp pillow coral is listed on Appendix II of CITES, protecting it from being traded without a permit. Current research is being conducted to ensure its safety.

Did You Know?

• Anomastraea is a monotypic genus, containing only the species Anomastraea irregularis.
• The crisp pillow coral forms colonies up to about 20 cm in height.
• It is found on the East African coast, southern Red Sea, Gulf of Aden, and parts of the Indian Ocean and Persian Gulf, but not in the Chagos Archipelago.
• The crown-of-thorns starfish is a major predator of this coral, with outbreaks linked to human activities such as overfishing and agricultural runoff.