Ceratopteridaceae Common Names:
Water Sprite, Indian Fern Origin:
Tropical regions of Africa, Americas, Asia and northern Australia. Mainly confined to shallow waters, particularly swamps, pools and ponds. Ideal position in aquarium
Best used as a floating plant, but can be grown rooted in the substrate. Lighting requirements
When left floating will grow well under any light that is not too bright; submersed plants grown in the substrate require moderate to high light. Growth rate
Moderate to rapid. Minimum Tank Suggestion
Suitable for any aquarium. Water parameters for Water Sprite
Soft to moderately hard (hardness up to 18 dGH), acidic to basic (pH 5.4 to 8) water, temperature 18-28C/64-82F. Does not like sudden significant changes in water parameters. Physical Description
This is probably the easiest aquarium plant to grow, at least when left floating, and because of its rapid growth it quickly assimilates nutrients including ammonia/ammonium and is therefore quite useful in new tanks. It assimilates nutrients primarily through the leaves rather than the roots.
The leaves, or more correctly fronds, since this is a true fern, can be somewhat variable in shape due to light, nutrients and water parameters. This makes identification of this species difficult, and it is often encountered in the literature under the names Ceratopteris pteridioides
and C. thalictroides
, although both these are distinct species. C. pteridioides
has blunt-lobed fronds (leaves), while C. thalictroides
has fronds that are deeply pinate with tips more slender than the subject species.
Daughter plants are readily produced from the sporangia on the older and alternate fronds. When left floating, the fronds may extend up to 50 cm (20 inches) across, and will block light from entering the aquarium; this is particularly useful to provide a darker environment such as for spawning fish. In such conditions, suitable substrate plants are any of the Cryptocoryne
species, Java Moss, etc. depending upon the amount of light getting through. Otherwise, the daughter plants can be separated and used as individual plants and the parent plant discarded in order to keep the water surface more open.
The dangling roots of floating Ceratopteris
provide admirable shelter for fry, and are used by the anabantids that build bubblenests. Many fish including anabantids, characins, etc., will regularly browse the roots for particles of food.
Formerly there were five species recognized [some authorities only recognize four] in the genus Ceratopteris
that was placed in the monogeneric family Parkeriaceae, thought to be unique because of its aquatic adaptations. Subsequent genetic analysis has shown the Ceratopteris
species to be clearly allied with those in the genus Acrostichum
, and Ceratopteridaceae is the family name for the clade that is now known to include these two genera. Some authorities place these two genera within the Pteridaceae family. Contributing Members
The following members have contributed to this profile: Byron