Avicennia marina (Grey Mangrove) Care Guide
Avicennia marina is a true grey mangrove tree with aerial pneumatophores, suited to advanced brackish and marine paludariums.
Overview
Avicennia marina, commonly called the grey mangrove, is a salt-tolerant mangrove tree of the family Acanthaceae. In the wild it grows in the intertidal zones of estuaries, where it copes with regular tidal inundation and high salinity. In aquaria it is kept as a specialty plant in brackish and marine paludariums and biotope displays rather than as a fully submerged plant.
Taxonomy
- Family: Acanthaceae
- Genus: Avicennia
- Scientific name: Avicennia marina
- Common name: Grey Mangrove
Habitat
The grey mangrove has one of the widest natural ranges of any mangrove, occurring along the east coast of Africa, across southern and southeastern Asia, Australia and into northern New Zealand. It colonises intertidal estuarine mudflats and tolerates high salinity by excreting salt through its leaves. Growth is reduced in excessively saline conditions; experimental work indicates that growth is maximal in roughly 25% seawater, and the roots exclude a large fraction of incoming salt.
Appearance
It forms a shrub or tree typically 3–10 m tall in the wild, taller in tropical climates. The leaves are about 5–8 cm long, glossy green above and pale silvery-grey beneath. A distinctive feature is the network of pencil-like aerial roots called pneumatophores, which project upward from the substrate (around 20 cm tall) and allow gas exchange in waterlogged, oxygen-poor mud.
Tank requirements
- Water type: brackish to marine
- Temperature: 22–30 °C (72–86 °F)
- pH: 7.5–8.5
- GH: 12–30 °dGH
- Lighting: high (moderate to high-output for indoor culture)
- CO2: not required
- Growth: slow; maximum height around 200 cm
- Placement: background / emersed (paludarium)
Avicennia marina is grown emersed: the root zone is flooded with brackish or saltwater and allowed to drain, while the foliage stays above water. Because the plant excretes salt onto its leaves, hobbyists rinse the foliage with low-mineral water to prevent crusting, and top off the system to keep salinity stable as water evaporates.
Propagation
Reproduction is by large fleshy seeds (propagules). These often begin germinating while still attached to the parent tree and drop as ready-formed seedlings, a strategy known as vivipary. In cultivation the propagules are floated or partly buried in substrate until they root.