This species is known only from the type locality, Río Negro, on the eastern slopes of the Andes, in Tungurahua Province, Ecuador, at 1,225m asl, although it presumably occurs more widely.
Habitat and Ecology
It occurs in premontane forest where the annual mean precipitation is 2,000-4,000mm, and the annual mean temperature is 18-24°C. It occurs sympatrically with Colostethus bocagei, C. kingsburyi and C. pulchellus. Its breeding habits are unknown, but the larvae probably develop in streams.
There is no information on the population status of this species, and it is possible that it has not been seen or looked for since it was first described.
Habitat destruction and degradation is a threat to this species. By 1996, the forest had been cleared at the type locality. However, forested areas remain nearby, in Parque Nacional Llanganates and Parque Nacional Sangay. Atmospheric and water pollution, and invasive alien species, are also threats.
The range of this species might overlap with Parque Nacional Llanganates and Parque Nacional Sangay.
Luis A. Coloma, Santiago Ron, Taran Grant 2004. Hyloxalus marmoreoventris. In: IUCN 2014