Whammin Watermelon Zoa Care Guide
Whammin Watermelon Zoa is a hardy, photosynthetic Zoanthus colony for reef aquaria. Easy to keep and fast-spreading, but colonies may carry palytoxin and require careful handling.
Compiled by Aquairi from published sources · Published · Updated
Overview
Designer zoa with bright pink skirt and green center, evoking watermelon flesh. Zoanthus are colonial anthozoans (often called "button polyps" or "zoas") whose polyps spread to encrust rock with brightly coloured patterns. Their vivid colours come in part from green-fluorescent-protein-like pigments.
Taxonomy
- Family: Zoanthidae
- Order: Zoantharia
- Genus: Zoanthus
- Scientific name: Zoanthus sp. 'Whammin Watermelon'
- Note: Zoanthus sp. 'Whammin Watermelon' is an aquarium trade morph of the genus Zoanthus, not a separately described WoRMS species
Habitat
This is an aquacultured Zoanthus morph propagated within the hobby rather than a wild-collected population, so material is sourced from fragmented colonies (Aquacultured).
Tank requirements
- Temperature: 24-26 degrees C
- pH: 8.1-8.4
- Salinity: 1.024-1.026 specific gravity
- Alkalinity: 8-11 dKH
- Calcium: 380-450 ppm
- Magnesium: 1280-1350 ppm
- Lighting: 50-150 PAR (medium), at least 8-12 hours per day
- Flow: low to moderate
- Suggested minimum tank maturity: 3 months
Feeding and lighting
Zoanthus obtain most of their energy from photosynthesis carried out by symbiotic zooxanthellae, so stable lighting is the priority. They can be target-fed about twice weekly with fine phytoplankton or zooplankton and amino acids using a pipette or turkey baster, although supplemental feeding is optional. They are rated among the hardiest, most beginner-friendly corals and tolerate parameter fluctuations.
Placement and compatibility
These passive zoas lack stinging tentacles that threaten neighbours and are considered reef-safe, shrimp-safe and fish-safe. Reef Builders recommends moderate to higher flow to prevent fungal or detritus problems on the mat. Colonies spread quickly by budding, so leave space around them. Reported growth is roughly 0.5-1 cm per month under good conditions.
Whammin Watermelon Zoa: Propagation Guide
Overview
Whammin Watermelon is a designer color morph of Zoanthus (family Zoanthidae) recognized by a bright pink skirt around a green center. It is one of an almost never-ending list of named strains the hobby has produced from these colonial button polyps. The polyps of a colony stay joined by a stolon, or coenenchyme mat, and Zoanthus is noted for a large number of distinct morphs within the same or similar species.
Reproductive Mode
Propagation in the aquarium is entirely asexual. A colony grows because offspring polyps remain attached to the parent by a fleshy stolon, and the mat buds new polyps outward across the rock. Hobbyists exploit this same stolon-and-budding biology to expand a Watermelon colony rather than relying on any sexual reproduction.
Fragging / Asexual Propagation
- Identify the polyps to remove and cut through the connecting stolon mat with a sharp razor blade.
- Follow the score line with coral cutters so the piece detaches; a diamond band saw is reserved for thick rock chunks.
- Prepare a soaked, dried frag plug or rubble, dry the underside of the frag, and dab on cyanoacrylate glue.
- Set the frag on the plug, hold briefly while the glue cures, then place it back in the tank.
- Recovery is confirmed when fresh tissue and new polyps appear.
Conditions for Propagation
These corals are hardy and forgiving, accepting lighting anywhere from lower to higher intensities over an 8 to 12 hour photoperiod. Healing frags do best in moderate to higher flow, which delivers nutrients to the polyps and removes waste. Left to grow, the stolon spreads and adjacent frags merge into a colorful mat.
Palytoxin Safety
Zoanthids and the closely related Palythoa can contain palytoxin, ranked among the most poisonous non-protein substances known. Wear gloves and eye protection during every cut, keep hands away from the face, and wash thoroughly afterward. Do not boil, heat, or scrape the rock, as this can aerosolize the toxin for inhalation. No antidote exists; care is limited to treating symptoms.
Common Challenges
After fragging, polyps often stay shut for a few days as the cut heals; steady water chemistry and gentle current speed the process. The pink-and-green coloration that defines Watermelon can shift with lighting and nutrient levels. The most serious challenge is handling palytoxin safely, not the cutting technique itself.