By Dr. Becker
Bromeliad plants are known not only for their striking flowers but also because their foliage forms a natural cup that holds water. In the U.S., they’re popular houseplants. If you’ve ever owned one, you know that in order to water it all you have to do is fill up the “cup” at the base of its leaves with water.
Bromeliads also grow in the wild, including in the rainforests in Brazil. There, rainwater naturally accumulates in the bromeliad’s “tank,” forming a tiny, natural pool.
While surveying for frogs inside bromeliads on rocky outcrops in the municipality of Santa Teresa, Brazil, researchers made a surprising discovery—a new species of tree frog.
New Tree Frog Species Discovered in Bromeliad
The new tree frog species was named Dendropsophus bromeliaceus and is also known as the Teresensis’ bromeliad tree frog, after the municipality and plant where it was found.
When comparing the new species to 96 other related frog species, the Teresensis’ bromeliad tree frog was distinguished by its small size, framed color pattern on its back and short webbing between its fourth and fifth toes.1
It’s thought that the frogs spend their tadpole stage in the bromeliad “pool” and later venture out into other territory. Many other frogs in the region begin as tadpoles in ponds or puddles on the ground.
After observing the frogs, the researchers suspect they use a variety of bromeliad species to breed and may be quite territorial. Also, the males are thought to do the parenting.
While this is not the only frog to make its home in a bromeliad (salamanders and snakes sometimes live in them too), the new species did exhibit some unique traits.
For instance, it avoided many bromeliad species, including seemingly those that only have one central tank, which could make the frogs vulnerable to predation or disturbance. They also may avoid bromeliads unable to store enough rainwater.
Further, only one or two tadpoles were found in each plant, which suggests only a few eggs were deposited per bromeliad (or, alternatively, that the tadpoles were cannibalistic).
According to the researchers, “Some bromeligenous frogs are known to lay a reduced number of eggs as a way to avoid competition among tadpoles.”
Hundreds of Species Call Bromeliads Home
Nature displays an amazing symbiosis of which bromeliads play an intriguing part. Bromeliads known as “tank bromeliads” can hold up to 5 gallons of water in its leaves, which is necessary since most live attached to other vegetation high up near the rainforest canopy.
While the plants are able to get some of their nutrients from falling debris and dust, frog feces and insect leftovers also provide an important source of nutrition. Meanwhile, tadpoles feast upon mosquito larvae living in the tank.
In fact, several hundred species of organisms live in bromeliads, including some that only live in bromeliad pools. Some of the organisms that depend on bromeliads’ tanks for survival include:2
As noted by Encyclopedia Britannica:3
“These small, discrete, relatively stable communities can serve as valuable models for studying biological processes.
In a typical food web of a bromeliad pool, energy and nutrients flow from solutes and organic detritus in the water, through bacteria and protozoa, to browsing or filter-feeding mosquito larvae, and thence to aquatic predators such as crabs, larvae of other mosquitoes, and damselflies.”
Illegal Collection of Bromeliads May Threaten Frogs
Rocky outcrops, where many bromeliads grow, are protected in that they cannot be converted to agricultural land. However, local people often collect bromeliads to use as yard decorations.
At least two bromeliad species used by the newly discovered Teresensis’ bromeliad tree frog are listed as vulnerable due to this type of overexploitation as well as habitat loss.4 According to the researchers:
“Illegal collection of these bromeliad species for ornamental purposes may affect bromeligenous frogs across rocky outcrops. Regulation regarding collection of these plants should be implemented to avoid overexploitation.”
The study further concluded that the Santa Teresa area of Brazil is an “important hotspot for anuran [frogs] and bromeliad conservation due to its high richness and number of endemic species.”
There are 94 recognized frog species in the area along with 107 bromeliad species, leading the researchers to conclude, “the rate of new species discoveries suggests Santa Teresa’s biodiversity is far from fully described.”