Townsend's Dwarf Salamander
© 2020 Wouter Beukema (1 of 22)
Parvimolge townsendi is a salamander with a total body length range of 37 – 42 mm, 13 costal grooves and 5 costal folds between the appressed toes. They have a head that is oval and blunt and is 4 ¼ times smaller than the length of the body. The eyes are larger than the distance from the eye to the tip of the nose with a diameter that is half . The nostrils had a diameter that is half of the pupil and the snout is swollen. From the side the outline of the upper jaw is straight. Both of the eyelids are fitted under a fold of skin. A groove from the eye extends to the gular fold, which then branches down behind the angle of the jaw. They have a finger length order of 3 > 2 > 4 > 1, with the first and fourth finger completely webbed. Their relative toe lengths are 3 > 4 > 2 > 5 > 1, with the first and the fifth toes being webbed. The tail is as long as the head and body; it is constricted at the base of the tail and has a circular cross-section. The anal lips are lined with papillae (Dunn 1922).
Parvimolge townsendi can be differentiated from other salamanders by having inner and outer rudimentary toes, their large nostrils in adults, and four to five costal folds between their appressed toes. Parvimolge townsendi is considered to be closely related to, Thorius pennatulus. However, T. pennatulus has 6 costal folds between its appressed toes and a longer tail than its head and body. They also have a brown dorsal stripe and black sides (Dunn 1922).
Dunn (1922) described Parvimolge townsendi as having a dark green dorsum and black ventrum. They also have blackish v-shaped markings on the back and upper surface of the tail that point toward the head. There is an indistinct light line that is on each side of their backs, and is most prominent where the arms and legs connect. A light line runs across the head between the hind borders of the eyelids. There are also irregular white markings on the sides between where the legs connect and the lower surface of the tail. They have white dots on their throats with mottled black and grey limbs. It is unclear if this description is in life or preservative.
Distribution and Habitat
Parvimolge townsendi can be found at Cerro de Los Estropajos near Jalapa, Vera Cruz, Mexico. It is known only from Guerrero, in the state of Hidalgo (Dunn 1922). It is found in forest fragments, located at an elevation between 980 and 1950 m a.s.l. The forests fragments are cloud forest and tropical semi deciduous. The species were found more in areas that had deeper litter depths (Sandoval-comte et al. 2012).
Life History, Abundance, Activity, and Special Behaviors
The eggs are unpigmented and yolkless. The diameter of the eggs ranged from 3.2 to 3.7 mm, and the embryo is surrounded by two membrane enclosed layers of transparent jelly (Duellman 1959).
Trends and Threats
Parvimolge townsendi was once thought to be extinct, however, in 2010 they were found in somewhat stable forest fragments. During their rediscovery, there were signs of disturbance such as garbage, tree felling, or agrochemical waste, resulting in loss of habitat and putting the species at risk. A more in depth study is needed to potentially find out more about the rapidly decreasing salamander (Sandoval-Comte et al. 2012). The species is currently listed as "Critically Endangered" on the IUCN Red List because of it is difficult to find, has had an estimated 80% population decline, and its habitat is fragmented (Parra-Olea et al 2008).
However, P. townsendi can be adaptable and have the ability to survive in shaded coffee plantations as long as the humidity levels are maintained, however they cannot survive if their environment is opened up. The drying up of their microhabitat is a main threat to the species (Parra-Olea et al. 2008).
Possible reasons for amphibian decline
General habitat alteration and loss
The species authority is: Dunn, E.R. (1922). “A New Salamander from Mexico.” Proceedings of the Biological Society of Washington 35: 5-6
The species was originally named Oedipus townsendi (Dunn 1922).
Prescott Townsend went with E.R. Dunn to Jalapa to collect specimens, which could be where the salamander gets its name (Dunn 1922); however, this was not explicitly stated by Dunn.
Duellman , W.E., (1959). ''The eggs and juveniles of the Plethodontid Salamander Parvimolge townsendi Dunn.'' Herpetologica, 15(1), 35-36.
Dunn, E.R. (1922). ''A new Salamander from Mexico.'' Proceedings of the Biological Society of Washington, 35, 5-6.
Parra-Olea, G., Wake, D., Hanken, J., García-París, M. 2008. Parvimolge townsendi. The IUCN Red List of Threatened Species 2008: e.T59328A11918563. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T59328A11918563.en. Downloaded on 15 February 2018.
Sandoval-Comte, A., Pineda, E., Aguilar-López, J.L., (2012). ''In search of critically endangered species: The current situation of two tiny Salamander species in the Neotropical Mountains of Mexico.'' PLOS One, 7(4), e34023.
Originally submitted by: Maxine Weber (first posted 2018-02-27)
Edited by: Ann T. Chang, Michelle Koo (2020-03-15)
Species Account Citation: AmphibiaWeb 2020 Parvimolge townsendi: Townsend's Dwarf Salamander <https://amphibiaweb.org/species/4119> University of California, Berkeley, CA, USA. Accessed Sep 24, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Sep 2021.
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