Description
Pipa myersi is a flat-bodied frog measuring about 36 - 42mm in snout-vent length. It has a narrow triangular shaped snout in the dorsal view and a rounded mandible in the lateral view. The snout has a “transverse, chevron-shaped depression” and protrudes over the lower jaw when viewed from the side at eye level. Trueb describes the distance between the lower mandible and tip of snout as marginally less than half the distance from the snout to the front of the eye. The eyes are relatively large, widely set, and directed dorsolaterally on the head. The arms are stout and short in length. The skin is covered in densely packed, uniform-sized tubercles along the dorsum while more varied sized tubercles are spread sporadically across the head and limbs. The skin on the ventrum is also covered tubercles, depressed and of uniform size. There are four fingers on the forelimbs that have trifurcated digits with two nubby projections straddling a larger, central projection. Relative finger lengths are 1 < 2 = 4 < 3. There are five toes on the hind limbs that are almost completely webbed. Relative toe lengths are 1 < 2 < 5 < 3 = 4 (Trueb 1984).

Pipa myersi is differentiated from sister species Pipa parva by having a denser collection of dorsal tubercles, a more rounded triangular shape of the snout and mandible, trifurcated digits, the absence of tubercles on the feet, lack of modification to skin around the mouth, ribs attached to transverse processes in adults, free-swimming, barbel-free, aquatic larvae, and lack of free, vestigial transverse processes for the coccyx (Trueb 1984).

In life, the dorsum is a dark grayish black and the venter is a grayish yellow. The irises appear pale bronze with brown-black speckling. Newly metamorphosed individuals were observed with a dark gray color with a silvery white peritoneum. When preserved, the dorsum appears reddish to gray-brown with dark brown spotting on hands and limbs. The venter is gray with red-brown spots on pectoral and gular areas concentrated about the mandible (Trueb 1984).

No variation in color has yet been documented. Some individuals were found to have six imbricate, presacral vertebrae while others were found to have seven (Trueb 1984).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia, Panama

View distribution map in BerkeleyMapper.

Pipa myersi has been encountered at low elevations in southeastern Panama and northeastern Columbia. It has been found along two locations of the Rio Chucunaque drainage of Provincia Darien in Panama, both of which locations involved the conjunction of smaller rivers. Notes from Charles W. Myers describe habitats that included clear/brown, shallow water within vernal pools lined with leaf litter, and vast overlaying canopy cover (Trueb 1984).

Life History, Abundance, Activity, and Special Behaviors
As Pipiods, fertilized eggs are deposited onto the backs of females to complete development, however, after hatching the larvae leave the skin chambers and complete development as free-swimming tadpoles in open water. The aquatic larvae also lack barbels around the mouth area (Duellman and Schlager 2003).

Tadpoles were often observed to be swimming near the surface of vernal pools at night as opposed to daytime, according to Myers’ field notes (Trueb 1984).

Trends and Threats
The quality and extent of suitable habitat is declining leading to greater habitat fragmentation, however, no population level data has been reported by the IUCN Red List (Solis et al. 2010).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation
Long-distance pesticides, toxins, and pollutants

Comments
This frog was formally described by Linda Trueb (1984) with references to the unpublished 1965 field notes of Charles W. Myers, containing species observations and ecological descriptions.

Based upon character-states among Pipiod frogs, Pipa myersi is a sister species to P. parva with the next closest relative being Pipa arrabali within the Pipa clade and genus Hymenochirus (Cannatella and Treub 1988).

The species epithet refers coincidentally to both the preferred habitat of the species, derived from the Old Norse ‘myrr’ meaning bog, swamp, or deep mud and Charles W. Myers, who collected the first known series of adults of the species. Myers’ name itself is derived from the French “myre”, meaning "keeper of the swamp" (Trueb 1984).

References

Cannatella, D.C. and Trueb, L. (1988). ''Evolution of pipoid frogs: intergeneric relationships of the aquatic frog family Pipidae (Anura).'' Zoological Journal of the Linnean Society, 94, 1-38.

Duellman, W. E. and Neil Schlager. 2003. Grzimek’s Animal Life Encyclopedia. Volume 6, Amphibians n.p.: Gale, 2003. eBook Collection (EBSCOhost)

Solís, F., Roberto Ibáñez, César Jaramillo, Querube Fuenmayor, Manfred Beier 2010. Pipa myersi. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.

Trueb, L. 1984. Description of a new species of Pipa (Anura: Pipidae) from Panama. Herpetologica 40(3): 225-234.

Species Account Citation: AmphibiaWeb 2013 Pipa myersi: Myers' Surinam Toad <https://amphibiaweb.org/species/5232> University of California, Berkeley, CA, USA. Accessed Jan 23, 2025.

Citation: AmphibiaWeb. 2025. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Jan 2025.

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