Comprehensive DescriptionRead full entry
Ameerega trivittata is a diurnal and terrestrial frog species that is part of the Dendrobatidae family with a snout-venth length of more than 35 mm, making it one of the largest Dendrobates frog. The females are slightly larger than the males with females growing up to 50 mm and males up to 42 mm. It has a snout that slightly projects. The tympanum is roughly half of the eye's diameter. Its back has fine granules and its lateral and ventral sides are smooth. Ameerega trivittata does not have webbing on its fingers or toes. The first finger is longer than the second. Their skin is toxic (Rodriguez and Duellman 1994; Ouboter and Jairam 2012; Cole et al. 2013). Similarly to others of its genus, A. trivittata can be identified by synapomorphies such as its granular dorsal skin texture that contain rounded or flattened granules that are distributed densely and evenly; in most dendrobatids, such as Epipedobates the granules and tubercles are irregularly scattered across the dorsal surfaces (Grant et al. 2006).
Ameerega trivittata differs from other frogs of its genus by a number of characteristics including its coloration and size (larger). It is also toothless, which allows differentiation between it and the sympatric toothed A. bassleri that has similar patterns (Silverstone 1976).
Both its front and hind legs are yellow-green to green to light-brown. The hind legs often have some black spots on them. Both the dorsum and the flanks are black. The ventral side is also black, but its posterior has green to blue markings. The hands and feet are green with scattered pale blue spots and the arms and legs are dark green. The posterior of the thighs is black with blue spots on them. The abdomen is black with irregular pale blue or cream spots. It has two lateral stripes on either side: a dorso-lateral stripe that is green to yellow from the snout to the hind legs and a lighter, whitish stripe that goes from the eye to the front and hind leg on the ventro-lateral side. In juveniles the two green-to-yellow stripes are usually all yellow. It has large spots in the armpit and the groin. It has a black venter with blue spots and a dark brown iris (Ouboter and Jairam 2012).
There are variations in coloration in specimens in different regions. In the Guianan Region, the lateral stripes can either be green, yellow-green, yellow, or orange. Although the dorsum is still black, there is no median dorsal stripe. In Suriname, A. trivittata displays green spots on the dorsal side of the limbs and light blue spots on the belly and ventral surface of the limbs (Cole et al. 2013).
The species authority is Spix 1824.
Ameerega trivittata, along with Colostethus talamancae and C. marchesianus, is an outgroup to other frogs of the the Dendrobates family (Roberts et al. 2006). The Ameerega genus is a sister group to Colostethus genus. This species has undergone several genus name changes due to the unclear phylogeny. Silverstone (1975) believed at this species should be classified under the Phyllobates genus because of finger morphology and chromosome evidence. He divided the Phyllobates genus into 4 groups and grouped this species together with Phyllobates bassleri into the trivittatus group due to their similar color. This group was later characterized by its vocalizations too. Myers (1978) reclassified the genus Phyllobates and the trivittatus species complex to the genus Epipedobates. Bauer (1986) later assigned the Ameerega genus to the trivittatus group. The clade is now identified by its synapomorphies (See Diagnosis) and its location because the Ameerega clade is found on in the Andes. The Ameerega genus is monophyletic with Allobates, Dendrobates, Epipedobates, Mannophryne, Oophaga, Phyllobates, and Ranitomeya (Grant et al. 2006).