Phyllomedusa trinitatis, known as the leaf-nesting frog, Trinidadian leaf frog, or Trinidadian monkey frog, is a species of frog in the subfamily Phyllomedusinae. It is found in Venezuela and the island of Trinidad.
Description
P. trinitatis is an arboreal frog with a bright green body, black and yellow eyes, and brown chin and chest, with parotid glands near its eyes. The color of the frog can differ depending on its local environment. It has smooth skin on its back dotted with small tubercles throughout. The frog lacks webbing on its fore and hindlimbs. Males lack vocal slits.
Distribution
The frog can be found throughout northern Venezuela in the following states: Distrito Federal, Sucre, Vargas, Miranda, Aragua, Carabobo, Yaracuy, Monagas, north of Bolivar and Guárico, and eastern Falcón. On the island of Trinidad, it can be found in many areas including Arima, Chatham, and the Northern Range.
Diet
Researchers propose that P. trinitatis stalks its prey because of its above-average size, slow movement, and toe pad shape. P. trinitatis is also known to eat insects such as Field crickets.
Predators
In a study conducted in Trinidad, West Indies, researchers studied the predation of Phyllomedusa trinitatis tadpoles by the dragonfly larvae Pantal flavescens, one of the predators of P. trinitatis during its tadpole stage. Researchers studied whether the larvae preferred tadpoles of P. trinitatis or Physalaemus pusulosus as prey, especially as the density of each species varied. Their results demonstrated that the relative prey density has no significant bearing on the dragonfly's preference of hunting for P. trinitatis tadpoles over Physalaemus pusulosus
Before adulthood, phorid flies in Trinidad are predators of P. trinitatis eggs and often decimate entire clutches.
Defense
This frog exhibits a host of defenses to evade predators and survive in hostile environments. As the frog flees from predators, it can release poison from glands found on its back. Males may also remain silent rather than calling to prevent attracting predators to their locations.
Furthermore, by probing the glands of P. trinitatis via electrical stimulation, scientists have isolated insulinotropic peptides from the frog's secretions. After purifying the secreted fluids of a few frogs, scientists purified four peptides that significantly promoted insulin release in BRIN-BD11 cells, cells capable of secreting insulin. Researchers isolated a 28-amino acid peptide fully homologous to the C-terminal of the precursor to dermaseptin BIV. These results suggest that P. trinitatis secretes an antimicrobial as part of its immune defense, though the specific mechanism of action is still unknown.
Other studies have identified other defense peptides secreted from the frog's skin. One study found 15 dermaseptin peptides with varying antimicrobial properties and evolutionarily conserved amino acid regions. One peptide discovered had only one cysteine residue in its structure (LTWKIPTRFCGVT), an uncommon distribution. The most effective antimicrobial peptides found were phylloseptin-1.1TR and 3.1TR. Like defense proteins found in other frogs, these peptides exhibited more potency against Gram-positive than Gram-negative bacteria.
Some studies provide insight into the structure-activity relationship between phyllo statins. Such studies of immunomodulation and insulinotropic activity may represent that these frogs can be used to develop drug templates for anti-inflammatory and type 2 diabetes treatment.
Mating
The mating season for P. trinitatis is usually around the end of the dry season until the beginning of the rainy season. The species exhibits sexual dimorphism, and females are generally larger than males.