CROWN-OF-THORNS STARFISH (Acanthaster planci)
A large species which are about 40 cm in diameter.
Feeds on coral polyps and can destroy entire reefs when occurring periodically in big amounts.
It has sharp, toxic spines and wounds can be very painful. Medical attention should be obtained.
BLUE SEA STAR (Linckia laevigata)
Encountered among algae-covered coral debris and in sea grass beds from shallow water down to 25 m.
This species prefers asexual reproduction separating an arm from its body, which converts to a complete animal.
BIG-PLATED SEA STAR (Choriaster granulatus)
This sea star is sometimes inhabited by a parasitic transparent fish that actually lives within its gut cavity.
FEATHER STAR (Oxycomanthus benetti)
Most frequently encountered feather star with many different colorations.
Primarily nocturnal in habit, it is not unusual to see them in daytime.
They are opportunistic; feeding when currents are optimum.
DIADEMA SEA URCHIN (Echinothrix diadema)
Mainly found on hard substrates, feeding on algae and coral polyps.
Its black spines are long, thin, hollow and very fragile (harmful,but not poisonous).
May be locally very abundant as they ar at the Similan Islands.
GLOBE SEA URCHIN (Mespilia globulus)
Very colorful member of the sea urchin family.
Most encountered singly on sandy parts within coral reefs not deeper than 20 m.