Jania · also called Finefork Coralline, Jania pedunculata var. adhaerens
Jania is a genus of small, jointed coralline red algae with fine, forking branches. J. adhaerens, now listed as J. pedunculata var. adhaerens, forms dense, bushy balls of pink and purple branches with white tips. It is calcified, so it draws down calcium and alkalinity, and it grows slowly. The hobby name Haliptilon is the same genus and has its own page.
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Quick facts
Category
Marine & Algae
Family
Corallinaceae
Native origin
Tropical to temperate seas worldwide
Care difficulty
Intermediate
Light
Bright indirect
Pet toxicity
Toxicity unknown
Light
Needs bright reef lighting. A reference entry for J. rubens asks for bright light, and hobby reports rate the genus moderate to high. Give a new cutting moderate light first and raise it over time. The white branch tips are normal on healthy plants, so do not mistake them for bleaching.
Water
Standard reef parameters: 23-27 C (74-80 F), salinity ~1.025 SG, pH 8.1-8.4. Being calcified, it needs well-balanced calcium (~400-450 ppm), alkalinity (8-11 dKH) and magnesium (~1300 ppm), and it competes with corals for them. Stable calcium and magnesium are the main care points.
Soil & potting
Attaches to rocks and also grows on other algae in the intertidal and upper subtidal, rather than in sand. A cutting can be tied to rubble with line or wedged in a crevice. It starts without its round shape, so set it where it has room to grow into a ball.
Environment — humidity, temperature, placement
Moderate water movement suits it, and one hobby guide reports a Florida form doing well with ample flow in the low to mid 70s F, so it may prefer the cooler end of 23-27 C (74-80 F). It works in a display or a macroalgae tank, and plants stay small.
Propagation
Growth is slow. A young cutting has no spherical shape and only develops it with time, so be patient. Trim a small branch from a healthy ball and tie it to rubble. Do not expect quick regrowth from a heavily cut plant, because this slow, calcified alga recovers gradually.
Toxicity detail
No toxicity data for tank animals was found, so the rating stays unknown. A reference entry lists J. rubens as likely suitable for reef and fish-only tanks. Calcified tissue tends to be unpalatable to herbivorous fish, and no coral smothering risk is recorded.
Varieties & cultivars
Natural forms are the wild species; cultivars are selectively-bred colour or variegation forms of the same plant.
Natural forms1
Finefork Coralline
Jania pedunculata var. adhaerens (formerly Jania adhaerens). A jointed coralline that grows into a dense, bushy ball of pink and purple branches, each tipped with white. Young cuttings lack the round form and develop it over time.
Give a cutting time, because the spherical shape only comes with growth.
KinStation
Bright indirect
Give a cutting time, because the spherical shape only comes with growth.