Epipedobates machalilla has a snout–vent length of 14.4 to 16 millimetres (0.57 to 0.63 in) for males and 15.0 to 17.6 millimetres (0.59 to 0.69 in) for females. Their heads are longer than they are wide, and the tympanum is small. The forelimbs have a moderate length and the fingers are unwebbed. The toes do not have lateral fringes and the terminal discs are expanded. The skin of the dorsum is dark-coffee in colour with a cream-yellow or cream-white stripe that shows some pink coloration toward the posterior. The upper surfaces of the hind legs are light brown in color; the forelegs are orange. The frog has a gold iris and cream ventral surfaces.[3]
Biology
The mating system of the Epipedobates machalilla includes cephalic amplexus. The female will produce around 15 eggs which are left on the ground or under leaves. The female will then leave, and the male will protect the development of the embryos and carry the larvae. When the tadpoles hatch (around 20 days after fertilization occurs), the male will take the tadpoles to riverbanks or pools of water so metamorphosis and growth can take place. He displays aggressive behaviour to protect the tadpoles.[3]
This frog's eggs, approximately 1.6 mm in diameter, are the smallest and least pigmented of any in the genus.[3]
Epipedobates machalilla is in the chemically defended genus Epipedobates and is one of the six species within this clade that possesses inconspicuous coloration (the ancestral state for Epipedobates). However, it is believed that with the high intra-specific phenotypic diversity observed within poison frogs and the role of diet in toxicity that there could be chemically defended E. machalilla populations.[4][5]
Distribution
Epipedobates machalilla is endemic to West Ecuador, where it lives in dry and low forests.[1][3] It mainly occurs in Azogues, Bolívar, El Oro, Guayas, Los Rios and Manabí and has been seen in the Choco rainforest. The species occurs at altitudes between 10 and 515 metres (33 and 1,690 ft).[3] Recently, the population has been declining due to agriculture and logging.[1]
^ abFrost, Darrel R. (2020). "Epipedobates machalilla (Coloma, 1995)". Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History. Retrieved 21 April 2020.
^Tarvin, Rebecca D.; Powell, Emily A.; Santos, Juan C.; Ron, Santiago R. & Cannatella, David C. (April 2017). "The birth of aposematism: High phenotypic divergence and low genetic diversity in a young clade of poison frogs". Molecular Phylogenetics and Evolution. 109: 283–295. doi:10.1016/j.ympev.2016.12.035. PMID28089841.
^Darst, Catherine R.; Menéndez-Guerrero, Pablo A.; Coloma, Luis A. & Cannatella, David C. (January 2005). "Evolution of dietary specialization and chemical defense in poison frogs (Dendrobatidae): a comparative analysis". American Naturalist. 165 (1): 56–69. doi:10.1086/426599. PMID15729640.
