Chubby diamond frog
Species Description: Scherz MC, Glaw F, Vences M, Andreone F, Crottini A 2016 Two new species of terrestrial microhylid frogs (Microhylidae: Cophylinae: Rhombopryne) from northeastern Madagascar. Salamandra 52: 91 - 106.
Rhombophryne botabota is different from all Plethodontohyla species because of the presences of a clavicle in the former. Exceptions are P. mihanika and P. inguinalis, which its differs from by the lack of expanded digital discs and having a dorsolateral color border, and P. fonetana, which it differs from by possessing knob-like terminal phalanges instead of Y-shaped. It can be confused with P. brevipes, however, R. botabota possess a supratympanic fold that is dark, not whitish, and it lacks inguinal spots. These two species also do not overlap in their distributions (Scherz et al. 2016).
Within its genus, R. botabota can be differentiated by coloration, morphology, and call. It has a distinct color border between the dorsum and lateral head distinguishes it from all other Rhonmbophryne species except for R. laevipes. Rhombophryne botabota is differentiated from members of the R. serratopalpebrosa group (R. coronata, R. guentherpetersi, R. ornata, R. serratopalpebrosa, R. tany, and R. vaventy) by the absence of superciliary spines. Rhombophryne botabota is superficially similar to R. guentherpetersi, who has superciliary spines that are very hard to see, however they can be distinguished by the lack of tibia glands in R. botabota. The snout-vent length in R. botabota is larger than R. mangabensis and R. minuta (24.2 - 32.2 mm vs 15.4 - 23.2 mm), and smaller than R. alluaudi and R. laevipes (24.2 – 32.2 mm vs 36.4 – 56.3 mm). Rhombophryne botabota also lacks inguinal ocelli, which are present in R. alluaudi and R. laevipes. It can be distinguished from R. longicrus and R. minuta by front limbs that are shorter (43.5 – 55.2% vs 70.4 – 74.7% of snout-vent length), heftier legs, and a wider head (144.2 – 169.5% vs 122.5 – 142.8%). Furthermore, R. laevipes, R. longicrus, and R. minuta all have longer tibia ( 48.3 – 52.3% vs 38.4 – 45.7% of snout-vent length) and longer hind limb length (175 – 184% vs 141 – 164% of snout-vent length) than R. botabota. It is differentiated from R. coudreaui, R. mangabensis, R. matavy, and R. testudo by having skin that is smoother, having clavicles that are ossified (instead of not ossified, reduced, or absent), and a narrower vertebral transverse processes. Furthermore, R. coudreaui, R. matavy, and R. testudo have shorter tibia (30.3 – 37.2% vs 38.4 – 45.7% of snout-vent length) and have a tibiotarsal articulation that does not exceed the axilla (vs a tibiotarsal articulation that does reach the tympanum and eye in R. botabota). It can be further distinguished from R. mangabensis by its call, which has a higher call repetition rate (inter-call interval 2,359 vs 6,420 ms), a dominant call that is lower in frequency (1272 HZ vs 2800 - 7800 Hz), and has no frequency modulations. Calls can also differentiate R. botabota from its sister species, R. alluaudi as the former has a dominant call frequency that is higher (1,272 ± 13 Hz vs 798 ± 23 Hz) and has a higher fundamental call frequency (621 ± 11 Hz vs 379 ± 34 Hz). Rhombophryne botabota also has a more ossified skeleton than R. alluaudi, does not have fusion of presacral VIII and sacrum, and a dorsal crest of urostyle that only runs 75% of its full length (vs running almost the whole length) (Scherz et al. 2016).
In preservative, the dorsal side is a light brown and it possesses symmetrical markings behind the scapular region. Each scapula has thin cream colored stripes running over them, and it is faintly striped on the dorsum with dark and light brown lines that run obliquely from the inguinal region to the midline. Inguinal spots are not present. The arms are cream on the ventral side with brown flecks and light brown on the dorsal side. The lower dorsal portion of the arm also has a dark brown cross band. There are fine cream and brown specks on the inside of the hand. The fingers are light brown with some zones of dark brown and cream. It is light brown on the dorsal side of its legs with two dark bands that cross the thigh obliquely, three stripes that cross the shank, and two that cross the tarsus. The anterodorsal portion of the thighs are brown with flecks of cream and the posteriorly is cream, but turns into a dark brown with cream colored eye spots toward the distal regions. The ventral side of the thighs are cream colored with flecks of brown on the anterior and posterior portions. The ventral distal and external portion of the shank is cream with light brown flecks, but becomes brown ocellated with cream approaching the inside of the knee. The ventral side of the tarsus is cream with brown flecks. The external foot is the same color as the tarsus with an area of dark brown. The sole of the foot is brown and has small specks of cream. Toes are speckled with cream and light brown while the tips of the toes are dark brown. The lateral sides of the head are dark brown, which is very distinct from the dorsal coloration. The cloacal region is dark brown. The brown of the dorsum merges on the flanks into the cream color of the ventrum. The ventral belly is an impeccable cream, and its chin is cream colored speckled with brown (Scherz et al. 2016).
Individuals seem to be consistent in morphology but not in coloration. There is a bit of variation in finger lengths, but the second and fourth finger were generally almost equal. While all specimens have light, thin lines running obliquely across the scapular area, some specimens showed dark spots posterior to these scapular lines. Additionally, posterior inguinal stripes are present in some and absent in others. Ocelli on the posterior thigh are either present, weak, or absent. Thigh cross bands are also not always present. Cross bands on the shank are almost always seen on specimens, but they differ in number and pigmentation. Ventral color is somewhat consistent across all specimens (Scherz et al. 2016).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Madagascar
Life History, Abundance, Activity, and Special Behaviors
The collection of specimens using pitfall traps indicates this is a fossorial species living in underground burrows (Scherz et al. 2016).
The call of this species consists of a sequence of honking notes that are repeated at regular intervals. Call duration is 505 ± 76 ms at 621 ± 11 Hz. The core call is only 151 ± 18 ms due to a long tapering off with the period between calls being 2359 ± 44 ms (Scherz et al. 2016).
Analysis of gut contents indicates that this species feeds on small gastropod snails belonging to Subulinidae and analysis of related species indicates small invertebrates are consumed (Scherz et al. 2016).
In the related species, R. laevipes, colubrid snakes (Liopholidophis) appear to be an important predator and may also feed on this species (Glaw et al. 2007).
Trends and Threats
Despite two of the three known localities being fairly well-protected with formal legal protection, the habitat that this species occupies is under threat of deforestation and habitat degradation, and there are still anthropogenic threats (such as mining and the harvesting of hardwood trees) that are compromising the expansivity and quality of the forest habitat. The forest between the protected areas, such as the Anjanaharibe-Sud Special Reserve and COMATSA are also being affected by anthropogenic activities, which may further degrade the habitat for this species (Scherz et al. 2016).
Ambolokopatrika is currently unprotected forest habitat for R. botabota, but is a component of a proposed protected area, which may aid in habitat protection and conservation for this species (Scherz et al. 2016). Other conservation actions proposed include site area protection and management, as well as resource and habitat protection (IUCN 2016).
Possible reasons for amphibian decline
General habitat alteration and loss
Bayesian Inference on 545 bp of the mitochondrial 16S rRNA gene fragment identified R. botabota as a member of the R. alluaudi complex with an intraspecific comparison of 10.7%. Rhombophryne botabota is sister to R. alluaudi with the next most closely related clade being composed of R. laevipes, R. mangabensis, R. matavy, R. savaka and R. testudo (Scherz et al. 2016).
The species epithet ,“botabota,” is a Malagasy word that translates to “chubby”, which is reflective of the chubby appearance of this frog. This epithet is pronounced as “buddha-buddha” (Scherz et al. 2016).
Glaw, F., and Vences, M. (2007). Field Guide to the Amphibians and Reptiles of Madagascar. Third Edition. Vences and Glaw Verlag, Köln.
IUCN SSC Amphibian Specialist Group. (2016). "Rhombophryne botabota." The IUCN Red List of Threatened Species 2016: e.T100339930A100339932. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T100339930A100339932.en.
Lambert, S. M., Hutter, C. R., Scherz, M. D. (2017). "Diamond in the rough: a new species of fossorial diamond frog (Rhombophryne) from Ranomafana National Park, southeastern Madagascar." Zoosystematics and Evolution, 93(1), 143. [link]
Scherz, M. D., Glaw, F., Vences, M., Andreone, F., Crottini, A. (2016). "Two new species of terrestrial microhylid frogs (Microhylidae: Cophylinae: Rhombophryne) from northeastern Madagascar." Salamandra, 52(2), 91-106. [link]
Originally submitted by: Chandler Gorman, Natalie Hoy, Grethe Steensgaard (2022-02-16)
Description by: Chandler Gorman, Natalie Hoy, Grethe Steensgaard (updated 2022-02-16)
Distribution by: Chandler Gorman, Natalie Hoy, Grethe Steensgaard (updated 2022-02-16)
Life history by: Chandler Gorman, Natalie Hoy, Grethe Steensgaard (updated 2022-02-16)
Trends and threats by: Chandler Gorman, Natalie Hoy, Grethe Steensgaard (updated 2022-02-16)
Comments by: Chandler Gorman, Natalie Hoy, Grethe Steensgaard (updated 2022-02-16)
Edited by: Ann T. Chang (2022-02-16)
Species Account Citation: AmphibiaWeb 2022 Rhombophryne botabota: Chubby diamond frog <https://amphibiaweb.org/species/8487> University of California, Berkeley, CA, USA. Accessed Aug 8, 2022.
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Citation: AmphibiaWeb. 2022. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 8 Aug 2022.
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