South American frog bite
| South American frog bite | ||||||||||||
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Floating leaves of Limnobium laevigatum |
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| Limnobium laevigatum | ||||||||||||
| ( Humb. & Bonpl. Ex Willd. ) Heine |
The South American frog bite ( Limnobium laevigatum ), in English West Indian Spongeplant, South American Spongeplant, Amazon Frogbit or Smooth Frogbit, is a floating aquatic plant from the frog-bite family ( Hydrocharitaceae ), which originates in South America, but is released from aquariums has also spread to warmer regions of North America and other parts of the world.
Occurrence
The South American frog bite is originally found in freshwater from Mexico to the Caribbean and tropical Central and South America . In California it was introduced as an ornamental plant and was able to spread as an invasive species over larger rivers to Redding and Arcata . The South American frog bite population has become a major occurrence in the Sacramento River and San Joaquin River basins , where it can overgrow ponds and irrigation canals. The plant has now also spread to Australia , Indonesia , Japan , Zambia and Zimbabwe . In Puerto Rico , Limnobium laevigatum grows on shallow ponds, slow-flowing, shady rivers, freshwater ditches and swamps, often at sea level.
description
Limnobium laevigatum is a floating aquatic plant with round, thick leaves, which can easily be confused with water hyacinth ( Eichornia crassipes ) due to its external similarity . Its morphology is similar to duckweed . The underside of the leaf is spongy, thickened and light green. Your young plants grow in rosettes from floating leaves that spread out on the surface of the water. A characteristic feature of the young plant is the presence of spongy aerenchymal tissue on the abaxial surface (underside) of the leaf. Mature plants grow up to 50 centimeters tall and have emergent leaves that are carried by petioles, but do not appear swollen like the spongy petioles of water hyacinths, which support buoyancy. The floating plant produces stolons that carry gametes. The flowers are small, white and unisexual. Female flowers have a lower ovary, the fruit itself is a fleshy capsule with a length of 4 to 13 mm and a diameter of 2 to 5 mm. The seeds are 1 mm long, ellipsoid and hairy. Limnobium laevigatum can be distinguished from Limnobium spongia by flower and leaf properties and distribution. Limnobium l. With good care, it forms a dense root system, which under certain circumstances can be up to 30 centimeters long and in which food particles can often get caught. The plant tolerates water temperatures of 10 to 28 ° C. It is not known that Limnobium laevigatum , unlike Limnobium spongia, occurs in western states.
reproduction
Limnobium laevigatum can reproduce and spread generatively through pollination and seed production as well as vegetatively through fragmentation of stolon segments. The young plants have a very large distribution capacity because they are small, swim and can easily be swept away by water currents. Due to its widespread distribution, the South American frog bite can overgrow a body of water very quickly at appropriate temperatures.
Use in the aquarium hobby
The South American frog bite is a popular and adaptable aquarium plant that is particularly popular during the running-in phase, as it quickly overgrows the water surface and its dense roots remove nitrates and phosphates from the water as nutrient drainers. This is particularly useful in aquariums that are heavily polluted with fish droppings and where there are strong algal blooms. In this regard, the South American frog bite is very competitive and can sustainably contain the spread of algae. Limnobium laevigatum is considered to be very undemanding, as it can grow well with different temperatures from 10 to 28 ° C and water values from very soft to very hard. It is often used as a spawning substrate in rearing tanks, as it provides shade, protection from above and its dense and networked roots protect the young fish from predators. A disadvantage of the tropical aquatic plant is that the tops of the leaves can rot quickly if they come into contact with water spray. They are also frequently attacked by water snails, which feed on the spongy material at the base of the leaves. It is recommended to hold it in the center and not on the edge of the pool in contact with the glass. Yellowish leaves in contrast to the usually bright green color indicate iron deficiency . Limnobium laevigatum is now available in most aquarium stores and aquatic plant dealers.
Invasive species
The South American frog bite has the property of forming dense mats on the surface of the water, which darken the water layers underneath so much that there is a lack of oxygen and the original biodiversity is severely restricted. The California Department of Food and Agriculture (CDFA) has characterized Limnobium laevigatum, along with other species such as Hydrilla verticillata and Eichhornia crassipes, as an invasive species since 2003 and mapped their range in California. The focus is on irrigation canals in the San Joaquin Valley. There the aquatic plants are either removed mechanically or controlled with herbicides such as diquat and glyphosate .
supporting documents
- Robert R. Haynes: Limnobium . In: Flora of North America Volume 22 . ( online )
- Christel Kasselmann : aquarium plants. Ulmer Verlag, Stuttgart 1995; 2nd, revised and expanded edition 1999, ISBN 3-8001-7454-5 , p. 332 f.
Individual evidence
- ↑ Amazon Frogbit. Fact sheet
- ↑ Datasheet Limnobium laevigatum (South American spongeplant) on www.cabi.org
- ↑ Geoffrey W. Howard, Mark A. Hyde and Mike G. Bingham: Alien Limnobium laevigatum (Humb. & Bonpl. Ex Willd.) Heine (Hydrocharitaceae) becoming prevalent in Zimbabwe and Zambia. BioInvasions Records (2016) Volume 5, Issue 4. Pages 221–225
- ↑ Limnobium laevigatum . Common Name: South American Spongeplant. Non-Native to Florida. UF IFAS
- ↑ Limnobium laevigatum South American frog bite on www.aquasabi.de
- ↑ a b c d e South American frog bite ( Limnobium laevigatum ) at Interaquaristik
- ↑ Limnobium laevigatum - South American frog bite on aquarium plant shop
- ↑ Limnobium laevigatum. Common Name: South American Spongeplant. Center for Aquatic and Invasive Plants University of Florida, Institute of Food and Agricultural Sciences
- ^ Matthew Perryman: Evaluating the invasive potential of South American Spongeplant, Limnobium laevigatum , in California's Sacramento-San Joaquin Delta, Conference 99th ESA Annual Convention, 2014. United States Department of Agriculture
