Palythoa

Palythoa (palys) are larger colonial polyps closely related to zoanthids, typically with a more muted earth-toned colour palette but a bolder, meatier presence. Includes species formerly sold as Protopalythoa, now synonymised. Place them in the mid-section of your tank under moderate PAR (75–200 PAR) with moderate flow. Standard reef parameters suit them well: alkalinity 7.5–9 dKH, calcium 400–440 ppm, and temperature 25–27°C. Palythoa are extremely hardy and tolerate a wide range of conditions.

Palythoa are straightforward to keep — they are photosynthetic and do not require target feeding, though they will readily consume small meaty foods and broadcast coral foods. Growth is moderate, and colonies spread across rockwork by producing new polyps from their shared tissue base (coenenchyme). Under good conditions, palys form dense mats that can cover substantial areas. They come in a range of colours from greens and browns to attractive fluorescent morphs.

CRITICAL SAFETY WARNING: Palythoa contain palytoxin, one of the most potent natural toxins known. While they are safe to keep in your aquarium, you must exercise extreme caution when handling, fragging, or removing them. Always wear protective gloves and eye protection when working with palys. Never scrub, boil, or expose them to hot water outside the tank — aerosolised palytoxin has caused serious poisoning incidents. Do not touch your eyes, mouth, or open wounds after handling. If you experience difficulty breathing, chest tightness, or unusual symptoms after handling palys, seek medical attention immediately. When fragging, work in a well-ventilated area and consider wearing a face shield. Despite these precautions, palys are widely and safely kept by millions of reefers — just respect the toxin and handle sensibly.