Frogs of Borneo.

Description
Meristogenys maryatiae is a small frog, with a male snout-vent length range of 31.3 - 37.1 mm and 65.1 - 65.5 mm for females, however only two females were used in the series to describe the species. They have long hind legs, which are about 70% of their body length (Matsui et al. 2010).

Diagnosis:

Maryati’s torrent frog is identifiable as a member of the Ranidae family because of its large hind legs, tympanum, toe pads, and the presence of a dorsolateral ridge. This specific species is distinct from other members of the genus Meristogenys because it is especially small. Specifically, M. poecilus and M. whiteheadi are two species that can be separated because of their larger size. Meristogenys maryatiae also has distinct dorsal dark spots, which separates it from all others, except M. amoropalamus and M. orphnocnemis. Meristogenys maryatiae has a golden, unicolored iris, which differentiates it from the bi-colored iris found in M. amoropalamus and M. jerboa. Meristogenys amoropalamus also has more foot webbing. Meristogenys orphnocnemis has ventral pigmentation on its tibia surface and less foot webbing. Meristogenys phaeomerus and M. whiteheadi have dark brown coloration on the posterior of its thighs with small light spots vs. the dark brown and cream color in M. maryatiae. The wider headband and larger eyes of M. macrophthalmus differentiate them from our focal species. Meristogenys maryatiae is most similar to M. jerboa (Matsui et al. 2010)

For more description, comparisons, coloration in life, variation, and larval description, please see Matsui et al. 2010.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Malaysia

Malaysian region distribution from AmphibiaWeb's database: Sabah

View distribution map in BerkeleyMapper.

Meristogenys maryatiae is endemic to Borneo Island, Malaysia and is specifically only found in the Crocker Mountain range along fast moving streams in western Sabah at an elevational range between 155 and 1,000 meters a.s.l (Matsui et al. 2010). Their habitat preference is inland waters, terrestrial and freshwater in forests and wetlands (IUCN 2018).

Life History, Abundance, Activity, and Special Behaviors
Meristogenys maryatiae is mostly nocturnal and very rare (Matsui et al. 2010).

There have only been a few females seen and it is described as a cryptic species (Matsui et al. 2010).

This species is semi-aquatic and is only found along mountain torrents, which they use for food, shelter, and reproduction (Matsui et al. 2010).

The breeding season is in late summer, most likely around August, as two females that were collected in late July had very mature eggs, indicating that breeding season was soon. There have also been recorded mating calls in late August, which sounded similar to that of M. jerboa. Many males have also been found in summer months at night surrounding the riverbeds and stream, but very few females have been seen (Matsui et al. 2010).

Meristogenys maryatiae appears to be oviparous, with the eggs having a black animal pole and the vegetal pole being pale yellow brown. There doesn’t appear to be any parental care, but more observations are needed (Matsui et al. 2010).

The tadpoles are usually found clinging to rocks in the rapidly moving streams, typically in shallower waters that have a depth of less than 20 cm (Matsui et al. 2010).

Trends and Threats
As of January 2018, the IUCN Red List classifies this species as “Least Concern.” This means that it has a stable population, is not highly threatened, and does not have extreme conservation concerns. However, it is likely declining in lowland areas and is threatened by agricultural pollution, water contamination, habitat loss, logging for road construction, urbanization and over harvesting (IUCN 2018).

Relation to Humans
The Maryanti’s Torrent frogs are collected and consumed as food outside of their protected range (IUCN 2018).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Disturbance or death from vehicular traffic
Local pesticides, fertilizers, and pollutants
Intentional mortality (over-harvesting, pet trade or collecting)

Comments

PHYLOGENETIC RELATIONSHIPS:

Meristogenys maryatiae was initially recognized as a unique species based on morphology. However, analysis of 12S rRNA and Cyt b mitochondrial DNA and POMC, Rag–1, and rhodopsin nuclear DNA indicate it is closely related to M. whiteheadi, M. orphnocnemis, and M. amoropalamus. However, the analysis was unable to determine a sister-group relationship (Matsui et al. 2010).

ETYMOLOGY:

The species was named after Professor Datin Mohamad Maryati who is an eminent entomologist who did a lot of herpetological work in the State of Sabah for the Institute of Tropical Biology and Conservation (Matsui et al. 2010).

References

IUCN SSC Amphibian Specialist Group (2018). "Meristogenys maryatiae." The IUCN Red List of Threatened Species 2018: e.T79096177A123533800. https://dx.doi.org/10.2305/IUCN.UK.2018-1.RLTS.T79096177A123533800.en. Accessed in February 2022.

Matsui, M., Shimada, T., Sudin, A. (2010.) “A new species of Meristogenys (Amphibia, Anura, Ranidae) from Sabah, Borneo.” Zoological Science 27(1): 61-66. [link]

Species Account Citation: AmphibiaWeb 2022 Meristogenys maryatiae: Maryati’s torrent frog <https://amphibiaweb.org/species/7578> University of California, Berkeley, CA, USA. Accessed Dec 23, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Dec 2024.

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