Physas

Their spiraled shell is markedly less elongate than that of Malayan snails and they are also slightly bigger. They do not play an important role in the control of unwanted algae. As they reproduce rapidly, it is best not to introduce them into an aquarium. Size: 1-2 cm.

• Goniopora (Poritidae)
• Planorbis
• Acropora (Acroporidae)
• Fungia (Fungids)
• Ceriantharia