From the IUCN Red List Species Account:

Range Description

This species is known from its type locality of Serrania Las Baldias, and from one other locality of Belmira in Paramo Morron, both of which are in Antioquia Department, Colombia, between 2,800–3,100 m asl. There is now also a photographic record of the species in a third locality (El Retiro) from 2010, but it needs confirmation and has been coded as "Presence Uncertain" in the distribution map (and is therefore not included in the calculation of EOO). It is unlikely that the species occur in between the known localities, as there is extensive livestock raising. Its EOO is 550 km².

Habitat and Ecology

This species occurs on vegetation along streams in natural forest edge in the high Andes, and has not been recorded from disturbed habitats. Breeding and larval development take place in streams.

Population

It is not a common species, and recent surveys have not found any specimens at the type locality. A decline has also been observed at Belmira. The most recent record of the species was apparently in 2001 (Museo Historia Natural Universidad de Antioquia). There have been recent survey efforts both at the type locality (2007 and 2009–2014) and Belmira (2012), but the species was not recorded (Colombia Red List Assessment Workshop pers. comm. July 2016).

Population Trend

decreasing

Major Threats

The main threats to this species are invasive species (trout) in both localities, and mining and agricultural activities (including pollution from agrochemicals) at the Belmira site. The 2004 assessment reported that chytridiomycosis was probably the major threat, leading to a catastrophic population decline. While there is currently no direct information confirming that chytrid has caused declines in this species, the lack of records in the 1990s is consistent with the pattern of decline in many other montane Atelopus species, and it is therefore reasonable to infer that the disease might be the cause of declines in this species (Colombia Red List Assessment Workshop August 2016).

Conservation Actions

Conservation Actions
This species has not been recorded in any protected areas. 

Conservation Needed
Habitat protection is required at the species known sites.

Research Needed
Further surveys are needed to determine if this species is still extant. 

Red List Status

Critically Endangered (CR)

Rationale

This species has a very restricted distribution—extent of occurrence (EOO) of 550 km²—and is known only from two locations in the northern portion of the Central Cordillera in Colombia. Its population apparently suffered drastic declines in the 1990s and the last known record is from 2001. Surveys at the two known sites have not recovered the species, and it is suspected that the number of mature individuals may be lower than 50. It is therefore listed as Critically Endangered (Possibly Extinct).

Citation

IUCN SSC Amphibian Specialist Group 2017. Atelopus sernai. The IUCN Red List of Threatened Species 2017: e.T54550A123132884. http://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T54550A49537715.en .Downloaded on 18 February 2019