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Zoas Taxonomy

Technically Sea Mat is just a common name, as are button polyps, colonial anemones, polyp rock, and false coral all primarily referring to Zoas. All of the Genus in this piece are part of the family Zoanthidae within the subclass Zoantharia in the class Anthozoa. Some of the members in the genus include Palythoa, Protopalythoa, Zoanthus, and Isaurus amongst others. Wilkens (1990) described some 300 individual species, however there looks to be less than a fifth of this realistically. (Borneman 1997) notes that an overhaul is coming in which we will see a reclassification of species, and in some cases genus

Zoas Physical Characteristics

To some extent the physical characteristics of the colony are influenced by it’s habitat of origin. Two identical colonies could appear somewhat different just like we see in other corals. Shorter more compact specimens with smaller mouths for the most part come from high current areas. The specimens with more elongated bodies, larger mouths, and longer tentacles more likely come from low current areas. Interestingly theses species occur in nature in a myriad of conditions from one extreme to another. Zoas colonies have been observed from reef crest taking blows from the crashing waves to tidal areas being exposed to air for hours during low tide. In fact it’s the durability of the species that make it such a good choice for aquariums. These Zoas tolerate a wide range of conditions and will flourish in nearly any aquaria.

Zoas have smaller polyps and reproduce by forming buds from the base of the mated tissue. The species unlike some of the others in the family does not incorporate sediment into its base. The center of the oral disk is tightly packed with tentacles and in nature can appear in a variety and combination of colors.

Palythoa have larger polyps but are also embedded in a common tissue. The texture of the base of both the Palythoa and Protopalythoa is rough from the incorporation of sand and sediment directly in the tissue. The assimilation of the material is thought to be both for defense and support. The larger polyps lend themselves to feeding on larger meatier foods.