Halimeda incrassata Care Guide
Halimeda incrassata is a calcified green macroalga that anchors in sand by a bulbous rhizoidal holdfast and grows in tropical seagrass meadows and lagoons.
Overview
Halimeda incrassata is a calcified green macroalga in the family Halimedaceae (order Bryopsidales). Its thallus is built from chains of segmented, calcified blades joined by non-calcified nodes, giving the alga a jointed, branched appearance. In the genus Halimeda the calcified segments contain roughly 60-80% aragonite, a form of calcium carbonate, which makes these algae notable sediment producers on tropical reefs.
Taxonomy
- Family: Halimedaceae
- Genus: Halimeda
- Scientific name: Halimeda incrassata
- Order: Bryopsidales
Habitat
The species occupies sandy-bottom habitats including lagoons, seagrass beds, mangroves and sand patches on outer reef slopes. It is reported on sandy bottoms among seagrass meadows at depths ranging from about 1-2 m down to 15-30 m. Thalli anchor in soft substrate by a bulbous holdfast a few centimetres long, formed from a network of branched rhizoidal siphons that bind sand grains and shell fragments.
Growth requirements
- Water type: marine (saltwater)
- Temperature: 24-28 °C (75-82 °F)
- pH: 8.1-8.4
- Lighting: high
- CO2: not required
- Growth rate: slow
As a calcifying alga, Halimeda draws calcium from the water and benefits from stable alkalinity, mirroring the conditions maintained for stony corals. Strong illumination supports its slow but steady deposition of aragonite segments.
Placement
In aquariums Halimeda is suited to a sandy bed where its rhizoidal holdfast can take hold; the KB record places it in the midground, reaching up to about 25 cm. Its rigid, reef-like form makes it a structural element rather than a fast-spreading nutrient sponge.
Propagation
Halimeda spreads readily by fragmentation and dispersal of detached segments. Sexual reproduction is rarely observed and, in the genus, is holocarpic: the whole thallus converts to reproductive tissue and dies after releasing gametes, a process that in Halimeda can be completed within about 36 hours.