The effect of pH on substrate preferences in the túngara frog (Engystomops pustulosus)
Poster Number
18
Format
Poster Presentation
Faculty Mentor Name
Marcos Gridi-Papp
Faculty Mentor Department
Biological Sciences
Abstract/Artist Statement
Acidification of the habitat, often through processes of acid deposition, has been a contributing factor toward recent declines in amphibian populations. Amphibians tend to be relatively acid tolerant, yet their semi-permeable skin allows slight decreases in substrate pH to negatively impact their survival fitnesses. Nevertheless, acidic elements like Sphagnum moss are commonly used as substrates for captive amphibians. We examined the substrate preferences exhibited by the túngara frog in tanks containing two options of bedding laid side by side. We made 252 tests comparing Sphagnum moss (pH 4) and coconut fiber (pH 5); 28 tests comparing coconut fiber with neutralized moss (pH 7); and 48 tests comparing Sphagnum moss (pH 4) with neutralized Sphagnum moss (pH 7). Our results revealed that juvenile túngara frogs prefer the coconut fiber over moss, but the preference is reverted if the pH of the sphagnum moss is neutralized. The importance of pH was confirmed by a strong preference for moss with neutralized pH over regular moss. Adults also showed a preference for the more neutral coconut fiber, but it was much weaker than in juveniles. Túngara frogs are tropical forest litter dwellers and one could expect them to cope well with acidic substrates. The clear preference of their juveniles for bedding with neutral pH indicates a potential fitness cost to exposure to substrates with low pH. Caution should therefore be exercised in the use of Sphagnum moss or coconut fiber with non-neutral pH as the single substrate in the husbandry of amphibians.
Location
DeRosa University Center, Ballroom
Start Date
30-4-2016 1:30 AM
End Date
30-4-2016 3:30 PM
The effect of pH on substrate preferences in the túngara frog (Engystomops pustulosus)
DeRosa University Center, Ballroom
Acidification of the habitat, often through processes of acid deposition, has been a contributing factor toward recent declines in amphibian populations. Amphibians tend to be relatively acid tolerant, yet their semi-permeable skin allows slight decreases in substrate pH to negatively impact their survival fitnesses. Nevertheless, acidic elements like Sphagnum moss are commonly used as substrates for captive amphibians. We examined the substrate preferences exhibited by the túngara frog in tanks containing two options of bedding laid side by side. We made 252 tests comparing Sphagnum moss (pH 4) and coconut fiber (pH 5); 28 tests comparing coconut fiber with neutralized moss (pH 7); and 48 tests comparing Sphagnum moss (pH 4) with neutralized Sphagnum moss (pH 7). Our results revealed that juvenile túngara frogs prefer the coconut fiber over moss, but the preference is reverted if the pH of the sphagnum moss is neutralized. The importance of pH was confirmed by a strong preference for moss with neutralized pH over regular moss. Adults also showed a preference for the more neutral coconut fiber, but it was much weaker than in juveniles. Túngara frogs are tropical forest litter dwellers and one could expect them to cope well with acidic substrates. The clear preference of their juveniles for bedding with neutral pH indicates a potential fitness cost to exposure to substrates with low pH. Caution should therefore be exercised in the use of Sphagnum moss or coconut fiber with non-neutral pH as the single substrate in the husbandry of amphibians.