Spirodela punctata Care Guide
Dotted duckmeat, a small floating duckweed with multiple roots per frond and reddish undersides that spreads fast and consumes excess nutrients.
Compiled by Aquairi from published sources · Published · Updated
Overview
Spirodela punctata is a small free-floating duckweed in the family Araceae, subfamily Lemnoideae. Members of Spirodela have several roots (rather than one as in Lemna) emerging from each frond and can turn reddish from anthocyanin. The species is morphologically intermediate between Lemna and other Spirodela. In 1999 it was proposed for transfer to the genus Landoltia based on biochemical and DNA studies, so it is also known as Landoltia punctata.
Taxonomy
- Family: Araceae (subfamily Lemnoideae)
- Genus: Spirodela (also classified under the genus Landoltia)
- Scientific name: Spirodela punctata
- Common name: Dotted Duckmeat
Habitat
The species' original range is Australia and South Asia, and it has since spread to the southern and eastern United States. It forms floating mats on the surface of still and slow-moving fresh water, often mixed with related duckweeds such as Lemna and Wolffia.
Tank requirements
- Light: low
- CO2: not required
- Temperature: 18-30 °C (64-86 °F)
- pH: 5.5-8.0
- GH: 2-18 °dGH
- Placement: floating
- Growth rate: fast
Care and growth
Duckweed multiplies very quickly and takes up nutrients from the water, which makes it useful for nutrient export, while its surface cover provides shade. Because it spreads aggressively it usually has to be skimmed off regularly; once introduced it is difficult to fully remove from a tank.
Propagation
Reproduction is vegetative: new fronds bud off the parent and may remain attached in small groups before separating. Some duckweeds overwinter as turions, dormant starchy shoots that sink and regrow when conditions improve.
Propagating Spirodela punctata (Dotted Duckmeat)
Overview
Spirodela punctata, dotted duckmeat (also placed in the genus Landoltia), is a tiny floating duckweed in the family Araceae, subfamily Lemnoideae. It is morphologically intermediate between Lemna and other Spirodela species and smaller than Spirodela polyrrhiza, with leaves up to about 7 mm and reddish undersides. Like other duckweeds it carries air pockets (aerenchyma) that let it float on or just under the surface.
It is a fast, undemanding plant that absorbs excess nitrogen and phosphate, making it useful for nutrient export.
Propagation Method
Reproduction is mostly by asexual budding (vegetative reproduction) from a meristem enclosed at the base of the frond. Daughter fronds form at vegetative nodes on the mother plant and stay attached by stipules before detaching as independent plants. In cool or unfavourable conditions some duckweeds also form turions that aid flotation and overwintering. In the aquarium you propagate simply by letting the colony bud and divide.
Step-by-Step
- Float a small starter clump of healthy fronds on a calm section of the surface.
- Provide light and nutrients; daughter fronds bud from the base and the colony doubles every few days.
- Let the attached daughter fronds mature until they detach naturally as separate plants.
- To seed a new tank, scoop a portion of the floating colony and transfer it across.
- Keep harvesting so the colony stays vigorous rather than crowded and stagnant.
Conditions for Healthy Growth
Dotted duckmeat thrives in warm (about 18-30 degrees Celsius), still, nutrient-rich water under low to moderate light, and tolerates a wide pH (5.5-8) and hardness range. No CO2 is needed. It grows readily in high-nutrient, eutrophic conditions, which is exactly why it works as a nutrient sponge.
Maintenance
Skim out excess plants roughly weekly. Regular harvesting removes the nitrogen and phosphate the fronds have absorbed and stops the layer becoming so thick that it blocks light and gas exchange below.
Common Challenges
The main challenge is runaway growth: an unmanaged colony shades everything below and starves the water of light. Strong surface agitation scatters and sinks fronds, while very lean water slows growth. Balance feeding, flow and frequent thinning to keep it healthy and contained.