C-137 zoas

C-137 is a vivid green zoanthid strain — a saturated, almost radioactive green across the disc and skirt that holds its color under both blue and whiter light. The name is a pop-culture nod (Dimension C-137), and the strain earns it: few green zoas stay this bright once they settle in, which makes it a anchor piece for zoa gardens that need a true green rather than another teal.

Care follows the standard hardy zoanthid pattern: low to medium light (about 75 to 200 PAR), moderate indirect flow, and placement on low to mid rockwork while the mat establishes. Green morphs are notably light-tolerant for zoas and keep their color higher in the tank than most, so C-137 can fill mid-level spots that wash out fussier strains.

Zoanthids feed mostly from their zooxanthellae, so light matters more than target feeding, but most colonies respond well to a light broadcast of fine planktonic food or amino supplements once a week. Keep nutrients present rather than zeroed out — colonies kept in ultra-low-nutrient water often stall, shrink, or close up. Stable alkalinity between 8 and 10 dKH, calcium 400 to 450 ppm, salinity around 1.025 to 1.026, and temperatures of 77 to 79°F cover the basics.

Placement is about growth control as much as light. Zoanthids spread by a creeping mat and will overgrow slower neighbors, so many keepers give a named strain its own rock island with sand on all sides. A new frag should start low while it acclimates, then move up gradually if you want tighter polyps and stronger color.

Handling note: zoanthids can contain palytoxin. Wear gloves and eye protection when handling or fragging, wash hands afterward, and never boil or pressure-wash zoanthid-covered rock.

Field notes — what keepers report

Keepers report the green stays true in photos taken under blue light with an orange filter — a strain that looks in person the way it looks online. Several say it is one of the faster green zoas they have kept, with mats doubling in a few months in a fed tank. Reports also note it tolerates being moved and fragged well, reopening within a day, and that polyps stay open under light levels that make many other strains stretch or close.