Page 195 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

FLOATING PLANTS 193

Salvinia auriculata Lemna minor Wolffia arrhiza
Butterfly Fern Duckweed Watermeal

ORIGINS Found widely in waterways from Mexico south ORIGINS Found throughout the world in both temperate ORIGINS Found throughout the world, in both temperate
as far as Paraguay in South America. and tropical regions. and tropical regions outside polar areas.
SIZE Leaves are 1 in (2.5 cm) long, ⁄2 in (1.25 cm) wide. SIZE Leaves are small, measuring about ⁄5 in (5 mm). SIZE Tiny leaves measure about ⁄25 in (1 mm).
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WATER Temperature 64–77°F (18–25°C); soft WATER Temperature 41-86°F (5–30°C); soft WATER Temperature 59–82°F (15–28°C); soft
(50–100 mg/l) and around neutral (pH 6.8–7.2). (50–100 mg/l) and around neutral (pH 6.5–7.2). (50–100 mg/l) and around neutral (pH 6.5–7.5).
PROPAGATION Simply break up the branches formed PROPAGATION Split off a few pieces from a mat; they PROPAGATION Split off a few pieces from a mat; they
by this fern. will soon start to replicate. will soon start to replicate.
Duckweed grows under a wide range of conditions,
even in an unlit aquarium, provided that it receives
some natural light. This plant is a useful addition to
a rearing tank and can serve as a food source for
vegetarian fish. If there are no plant eaters to keep
its growth in check, remove some of the duckweed
with a net to prevent it from choking the surface.

This is another species for which bright lighting is
very important. If the tank has a glass cover, it must Watermeal is the smallest flowering plant known.
be tilted slightly so that condensation droplets do Although the genus Wolffia comprises eight
not fall on to the ferns, because this will cause the recognized species, they are all very similar in
plants to rot. It may occasionally be necessary to appearance. Watermeal is easy to grow, with its
thin out the growth, because Butterfly Fern can green coloration turning reddish under bright
spread rapidly into a dense mat that will prevent light. A ready supply of trace elements in the
light from reaching other plants beneath. water will encourage rapid growth.

Riccia fluitans Ceratopteris thalictroides
Liverwort Watersprite

ORIGINS Another widely distributed species, occurring in ORIGINS Grows widely throughout the
parts of the Americas, Asia, and Europe. world’s tropical regions.
SIZE Leaves typically no more than ⁄12 in (2 mm). SIZE Up to 24 in (60 cm) tall when rooted.
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WATER Temperature 68–82°F (20–28°C); hard WATER Temperature 72–86°F (22–30°C); soft
(100–150 mg/l) and around neutral (pH 6.5–7.5). (50–100 mg/l) and slightly acidic (pH 6.5).
PROPAGATION Break off a piece from an existing clump PROPAGATION Young plants develop on the edges
to add to a new tank. of existing leaves.
This is one of the most versatile of all aquarium
plants, since it can either be rooted in the substrate
or float on the surface. When allowed to float, it
has a more flattened appearance, with the leaves
appearing slightly broader, while the white roots
simply trail down in the water. Watersprite’s
coloration is variable, depending not only on
the lighting conditions but also on the levels of
dissolved nutrients in the water. Bright lighting
is essential if it is to thrive, but if the illumination
is too intense, the leaves may become scorched
Liverwort differs from other floating plants in and die back. Watersprite is not a long-lived plant,
that it grows just below the surface, where it being effectively an annual. Mature leaves produce
ultimately forms large balls. It can also be grown buds that ultimately give rise to new plants. These
out of water in damp mud. It will thrive under may be separated from the parent plant once they
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relatively hard water conditions in the aquarium. are about 1 ⁄2 in (4 cm) across, but they can also
Liverwort is especially valuable in tanks housing be left to detach themselves. They will then float
livebearers, providing fry with a safe refuge from up to the surface and develop there naturally,
the predatory attentions of other tank occupants. sometimes protruding above the waterline.

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