This short series of posts will offer suggestions for planning and establishing biotope ripariums to represent the aquatic habitats of three different regions. Aquarium biotopes create the most natural-looking combinations of plants, substrates and livestock, while also providing excellent opportunities to learn about the flora, fauna and ecology of beautiful wild places. We should all build more of them!
Part 1: Southern United States, Mexico & Central America
Above, Mexico river biotope riparium in 120-gallon aquarium.
The Biotope: the freshwater aquatic habitats in this vast area are represented by a wide variety of distinctive ecosystems that include swamps, rivers, lakes and mountain streams, but there is a certain amount of overlap in the aquatic plant and fish diversity. While planning a riparium biotope for specific kinds of fish, the aquarist should focus on a specific area and habitat to guide plant, hardscape and substrate choices.
Hardscape & Substrate: try to find photos or scientific descriptions for the specific area you wish to represent. There is wide variety. Mountain streams in the Southern United States, Mexico and Central America are typically lined with large rounded boulders and finer gravel particles. Swamps, marshes and quiet creeks can be recreated in the aquarium with gentle water flow and finer gravel substrate combined with sunken manzanita twigs and oak or magnolia leaves. Lakes often have more angular boulders and beds of sand or fine gravel. A large sunken driftwood stump can also help to recreate a lake environment.
Livestock: the most popular aquarium fish from this region are livebearers in Family Poecilidae and various cichlids (Family Cichlidae). Among fish from the Southeastern United States, an area with exceptionally high fish biodiversity, are a few other groups kept in aquariums, such as cyprinids and darters. Very small livebearers, such as Heterandria formosa, can be housed in nano tanks of just a few gallons, while large Central American cichlids or groups of Poecilia sailfin mollies might require aquariums of 75 gallons or larger. There are also many fish species options from this area to inhabit medium-size tanks, such as wild type Xiphophorus platies & swordtails and Cryptoheros cichlids. The Mexico-endemic livebearer family, Goodeidae, also includes fascinating and beautiful aquarium choices.
Riparium plants: fortunately, a number of the best, well-tested riparium plant choices originate from this area. The following lists several of these with notes:
- Asclepias curassavica "Mexican Milkweed" - this tropical relative of the familiar monarch butterfly food plant grows in wet, sunny places throughout the Southern United States, Mexico and Central America. It is one of the easiest riparium plants to grow and bloom. Combine it with grassy riparium plants, such as Cyperus, to create a riverbank or marsh environment.
- Cyperus spp. dwarf "Umbrella Sedge" - there are three or four different small-growing Cyperus species available for sale in the gardening trade. While they may not necessarily be from this area, there are dozens of native species of Cyperus from wet habitats in this area that share the characteristic tall stalk with a a whorl of grassy leaves on top, so the common garden varieties will work well as riparium stand-ins.
- Echinodorus cordifolius - another species that occurs throughout this area, this is also the Echinodorus swordplant that adapts best as an emersed plant in riparium conditions. The all-green species plant grows to a large size relatively fast, so it is a good choice for filling out a larger planting, while the white-variegated cultivar E. cordifolius 'Tropica Marble Queen', stays shorter.
- Ruellia brittoniana "Mexican Petunia" - another widespread plant in this area, R. brittoniana is available as several different cultivars that vary in stature and flower color. The dwarf forms of Ruellia brittoniana have foliage that reaches out across the water horizontally and are especially useful for adding visual depth and hiding riparium planters. Provided with good light and fertilization, Mexican petunias will flower abundantly in the riparium with white, blue, pink or violet blossoms.
- Spathiphyllum spp. "Peace Lily" - this familiar houseplant originates from the tropical species that grow along rainforest swamps and streams in Southern Mexico and Central America, as well as South America. Use it with the above species and others to create a biotope for poecilids and cichlids from these more tropical areas.
Zephyranthes spp. "Rain Lily" - this true lily grows from a bulb and blooms with beautiful white, yellow or pink flowers. It is very easy to grow, but the the flimsy, onion-like leaves provide little foliage, so it should be combined with other more robust plants in the riparium layout.
With some research, a dedicated hobbyists can find other possibilities among hardscape, livestock and riparium plants choices to recreate aquatic biotopes for this region. Some of the plants mentioned in the list above are actually represented by numerous different species in the Southern US, Mexico and Central America that might be difficult to find, but the species available as garden plants, including the Riparium Supply selections in our online store, can work well as stand-in representatives.
Thank you for reading! Stay tuned and watch for our next two articles to offer more ideas for planted riparium biotopes.