Scinaia

Scinaia · also called Branching Hex, Branching Hex (Purple Form)

Scinaia is a red macroalgae with rubbery, repeatedly forking branches, often mislabeled in the hobby as Rhodopeltis. Kept forms run from deep red to a pale reddish purple that shifts with lighting. Keepers have little experience with it, and a related species is known to collapse without warning.

Educational only. Some KinStation entries are reviewed by licensed veterinarians, but none can replace an in-person exam. Always consult a licensed veterinarian or board-certified specialist for diagnosis, treatment, or any decision affecting your pet's health.

Quick facts

Category	Marine & Algae
Family	Scinaiaceae
Native origin	Temperate and tropical coasts of the Atlantic, Indian and Pacific Oceans
Care difficulty	Advanced
Light	Medium light
Pet toxicity	Toxicity unknown

Light

Keepers have little experience with its light needs, so start with moderate reef lighting and change it gradually. Lighting sets the color: the pale purple form owes its shade to the light it grows under and can turn maroon or deep red when light is low. Treat a color shift as a cue, not a fault.

Water

Standard reef parameters: 23-27 C (74-80 F), salinity ~1.025 SG, pH 8.1-8.4. Keep conditions stable, with clean water and no sudden changes. A reference entry for S. complanata says it may need iodine additions to stay healthy, so a modest iodine routine is worth trying, though firm evidence for this is lacking.

Soil & potting

Attaches to hard material rather than rooting in sand. In the wild, S. complanata forms clumps on shells, coral fragments and stones. In a tank, anchor a piece to rock or rubble with thread or line. Keep handling to a minimum, since the soft branches can fall apart.

Environment — humidity, temperature, placement

Grows in clear subtidal water in the wild, on rocky bottoms. Moderate, steady flow in a display or macroalgae tank at standard reef temperature, 23-27 C (74-80 F), is a sensible start. Keepers have little data on its flow needs, so watch the plant closely after any change.

Propagation

Keepers have little record of how it spreads in tanks. Cutting a branch and anchoring it on new rock is the likely route, but mishandling can make these soft plants fall apart, so trim sparingly. A plant can look healthy one day and dissolve the next, so keep a backup piece if you can.

Toxicity detail

No toxicity data for tank animals was found, so the rating stays unknown. One reference lists a related species as likely suitable for reef and fish-only tanks. No grazing deterrent or smothering risk is documented. A plant that dissolves suddenly can foul the water, so remove dying tissue quickly.

Varieties & cultivars

Natural forms are the wild species; cultivars are selectively-bred colour or variegation forms of the same plant.

Natural forms2

Branching Hex

Scinaia sp. A red alga with rubbery, branching growth in a distinctive pattern. It is often mislabelled as Rhodopeltis.

Little is recorded about its care, so keep conditions stable and change lighting gradually.

Branching Hex (Purple Form)

Scinaia sp. A thicker-branched morph of Branching Hex with a rubbery feel and a pale reddish-purple tone. That color depends on the lighting, and it can turn maroon or deep red in low light.

Lighting sets its color, so expect deeper reds if the light is low.