Palythoans

Palythoans are a genus of marine invertebrates belonging to the order Zoanthidea, commonly found in tropical and subtropical oceans worldwide. They are colonial animals, forming dense mats or encrusting formations on various substrates, including rocks, coral skeletons, and even shipwrecks. Each individual polyp within a palythoan colony is relatively small, typically ranging from a few millimeters to a couple of centimeters in diameter. These polyps are connected by a thick, fleshy tissue called a coenenchyme, which can give the colony a gelatinous or rubbery appearance.

The coloration of palythoans is highly variable, with many species displaying vibrant and diverse patterns, often including shades of brown, green, orange, and purple. This coloration is often due to symbiotic algae, known as zooxanthellae, that live within the palythoan tissues and perform photosynthesis. Palythoans are filter feeders, extending their small tentacles to capture plankton and other suspended organic matter from the water column. They are an important part of reef ecosystems, providing habitat and food sources for other marine organisms.

Some palythoan species are known to produce potent toxins, most notably palytoxin, one of the most toxic non-protein substances known. This toxin can be found in their tissues and mucus, and can cause severe irritation or illness if handled improperly. Due to their attractive appearance and relative hardiness, certain palythoans are also popular in the marine aquarium hobby.