Diet

• Zoanthus species are suspension-feeding and carnivorous zoantharians that capture plankton, small invertebrates and other organic particles with their tentacles.

• Prey is immobilized by nematocysts and transported to the mouth for digestion.

• Many species also contain photosynthetic dinoflagellate symbionts, which can provide additional nutrients through photosynthesis.

• The relative importance of photosynthetic and heterotrophic feeding varies among species and environmental conditions.

Range

• Zoanthus is a widely distributed marine genus occurring in tropical and subtropical waters of the Indo-Pacific and Atlantic regions.

• Species occur on shallow reefs and rocky shores, with several species recorded from the tropical eastern Pacific.

• Zoanthus species recorded from the eastern Pacific include Z. pulchellus and Z. sociatus, with specimens documented from shallow coastal habitats in Ecuador.

• The genus is also represented in the Caribbean and western Atlantic, as well as throughout much of the tropical Indo-Pacific.

Habitat

• Zoanthus commonly grows on exposed rocks, reef surfaces, coral rubble and other hard substrates in shallow marine environments.

• Colonies can tolerate considerable wave action and periodic exposure during low tides, allowing some species to occupy intertidal habitats.

• Many species occur on shallow coral reefs and rocky reef flats where sunlight and water movement provide suitable conditions for both photosynthesis and suspension feeding.

• Colonies may form extensive mats that cover rocks and other available hard surfaces.

Description

• Zoanthus is a genus of colonial zoantharians in the family Zoanthidae.

• Individual polyps resemble small sea anemones but generally lack the heavy mineral encrustment characteristic of several other zoantharian groups.

• The polyps have a cylindrical column, a broad oral disc and a marginal ring of numerous relatively short tentacles.

• Polyps are connected at their bases by stolons or common tissue and may form dense colonies ranging from small clusters to extensive mats.

• Colour is highly variable among species and colonies, including green, brown, olive, purple, blue, yellow, orange and reddish forms.

• Some species have strikingly coloured oral discs and tentacles, while others are relatively uniform in colour.

• The genus includes species adapted to shallow, wave-exposed environments, and its colonies can become an important component of the benthic community on tropical rocky reefs.