Joker Zoa Care Guide
A Zoanthus morph with a green skirt, purple ring and orange mouth; a hardy, photosynthetic encrusting zoanthid for reef aquariums.
Compiled by Aquairi from published sources · Published · Updated
Overview
Joker Zoa is a named color morph of Zoanthus, a colonial zoanthid in the family Zoanthidae. The morph is recognized by a green skirt, a purple ring and an orange mouth. Zoanthids form colonies of small polyps that spread across rock as an encrusting mat and are commonly called zoas or button polyps. They are hardy and tolerant of parameter fluctuations.
Taxonomy
- Phylum: Cnidaria; Class: Anthozoa (Hexacorallia); Order: Zoantharia
- Family: Zoanthidae
- Genus: Zoanthus Lamarck, 1801
- Scientific name: Zoanthus sp. 'Joker' (aquacultured designer morph)
Biology
Zoanthus is a zooxanthellate genus: the polyps host symbiotic algae (zooxanthellae) and obtain most of their energy from photosynthesis, supplemented by capturing fine food particles with their tentacles. Polyps are connected by shared tissue and reproduce asexually by budding, allowing a colony to spread over a rock surface.
Tank requirements
- Salinity: 1.024-1.026
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Alkalinity (dKH): 8-11
- Calcium: 380-450 ppm
- Magnesium: 1280-1350 ppm
- Nitrate: below ~15 ppm; Phosphate: below ~0.1 ppm
- Lighting: medium, around 50-150 PAR
- Flow: low to moderate (enough to keep detritus off the polyps)
- Minimum tank maturity: about 3 months
Care and placement
Zoanthids tolerate a range of lighting spectrums and intensities; medium light suits this morph. They benefit from moderate flow, since low-flow areas allow detritus and algae films to settle on the polyps. They are peaceful and reef-safe with other corals, fish and invertebrates. As an encrusting coral it spreads across the rock over time.
Feeding
The colony is primarily photosynthetic through its zooxanthellae. Optional target feeding with fine foods such as phytoplankton or zooplankton, roughly twice a week, can support growth, but is not strictly required.
Joker Zoa: Propagation Guide
Overview
Joker is a designer Zoanthus morph (family Zoanthidae) with a green skirt, a purple ring, and an orange mouth. It is one of the many trade-named strains hobbyists circulate from these colonial button polyps rather than a separate species. The polyps of a colony remain joined by a stolon, or coenenchyme mat, and Zoanthus is known for displaying a large number of color morphs of the same or similar species.
Reproductive Mode
Propagation in the aquarium is asexual. Colonies form because offspring polyps stay attached to the parent by a fleshy stolon, and the mat buds new polyps outward across the rock. This stolon budding is how a Joker colony naturally expands, without any sexual spawning.
Fragging / Asexual Propagation
- Select edge polyps and cut through the connecting stolon mat with a clean razor blade.
- Trace the cut with coral cutters until the section frees; a diamond band saw is used for thick rock bases.
- Soak and dry a plug or rubble, dry the frag base, then apply a little cyanoacrylate glue.
- Press the frag onto the plug, hold briefly to cure, then return it to the tank.
- New tissue and polyps confirm the frag has taken.
Conditions for Propagation
Zoanthus are hardy and adaptable, accepting lighting from lower to higher levels over roughly an 8 to 12 hour photoperiod. Healing frags prefer moderate to higher flow so the polyps are fed and waste is removed. As the stolon spreads, grouped frags merge into a colorful mat.
Palytoxin Safety
Zoanthids may carry palytoxin, among the most poisonous non-protein substances known. Wear gloves and eye protection during fragging, keep your hands off your face, and wash thoroughly afterward. Do not boil, heat, or scrape the rock, because heating can aerosolize the toxin for inhalation. No antidote exists; only symptoms can be treated.
Common Challenges
Freshly cut polyps may stay closed for several days while healing; consistent chemistry and gentle flow assist recovery. The green, purple, and orange palette that names Joker can shift with lighting and water quality. The greatest challenge is safe palytoxin handling rather than the cutting technique.