Species Description: Koehler J, Glaw F, Pabijan M, Vences M 2015 Integrative taxonomic revision of mantellid frogs of the genus Aglyptodactylu (Anura: Mantellidae). Zootaxa 4006: 401-438.
© 2016 Andreas Nöllert (1 of 10)
Aglyptodactylus chorus can be differentiated from other species of Aglyptodactylus by the combination of the absence of marbling on the surfaces of the posterior thigh, absence of a vertebral line, presence of dark lines and blotches in the loreal region, well-developed webbing of the toes, and a slender body. More specifically, A. chorus can be differentiated from A. australis by the former being smaller, being more slender, and lacking marbling on the thighs. The focal species can be differentiated from A. laticeps and A. securifer by the former having a narrower head, having more extensive toe webbing, and having a smaller inner metatarsal tubercle. The absence of marbling on the posterior thighs, absence of a vertebral line, and a more pointed snout differentiates A. chorus from A. madagascariensis. Only a longer advertisement call and genetics can differentiate A. chorus from A. inguinalis. Moreover, the call of A. chorus is distinct from the calls of other Aglyptodactylus by displaying a lower pulse reputation rate. The call has shorter note duration than A. australis, A. madagascariensis, and A. securifer. The call has a similar range in pulse repetition rate and note duration to A. laticeps, but A. chorus lacks increases in pulse rate within notes (Köhler et al. 2015).
After four years in preservative, the head, dorsum, and dorsal surfaces of the limbs of the holotype were greyish. The upper lip was white. There were dark, irregular interorbital markings that extended onto the eyelid. The pupils were white and the iris was black. The loreal and temporal regions were greyish with the loreal region having small dark brown spots. There was a dark brown line on the supratympanic fold and an irregular dark brown blotch posterior to the tympanum. On the dorsum there were small brownish spots and elongated markings. Small black markings could also be found on each side of the inguinal region. The flanks were cream-colored. The arms were grey and had one dark crossband on the lower portion. There were also small back spots on the inner side of the lower arm. The posterior side of the upper arm had dark spotting. The dorsal surfaces of the hands were white and covered with very small grey spots and the dorsal surfaces of the feet were cream with small grey spots. The thighs and shanks had dark crossbands and the surface of the posterior thigh had a reticulated pattern. On the dorsal surface of the feet, there are two or three narrow crossbands and the ventral surfaces of feet were grey. The belly and throat were cream in addition to the anterior venter and ventral surfaces of the arms. The cloacal region was dark brown (Köhler et al. 2015).
In life, the dorsal surface was yellow-cream with some golden tint. This gold tint was not present in the loreal and tympanal regions. The venter was yellow-white with the throat appearing darker. The iris periphery was gold with fine brown reticulation and a black pupil. There was dark brown spotting on the palmar and plantar surfaces. The nuptial pads were dark brown. The color patterning of the rest of the animal was similar to coloration in preservative (Köhler et al. 2015).
Individuals differ in number of dark dorsal markings, patterning, size of dark spots in the loreal region, presence of dark interorbital markings, amount of facial spotting, and coloration of the lower lip (cream-colored to white). The venter may have grey spots and the dorsum may be reddish brown (Köhler et al. 2015).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Madagascar
Life History, Abundance, Activity, and Special Behaviors
The advertisement call is soft and consisted of 3 – 4 distinctly pulsed notes lasting 73 – 140 ms that were repeated in regular intervals. Notes consisted of 4 – 6 well-spaced pulses that repeated at an average of 37.3 pulses per second. Amplitudes increased within notes and calls as they progressed. The frequency ranged from 900 – 4000 Hz and had a maximal call energy between 2756 – 2820 Hz (Köhler et al. 2015).
Single individuals could also be found during the day on the forest floor (Köhler et al. 2015).
Blommersia variabilis, Boophis tephraeomystax, and Guibemantis cf. kathrinae could also be heard calling at the same time as A. chorus (Köhler et al. 2015).
Trends and Threats
Possible reasons for amphibian decline
General habitat alteration and loss
Based on Maximum Likelihood and Bayesian Inference analyses of 539 base pairs of 16S rRNA, A. chorus is most closely related to A. inguinalis. The clade formed by those two species is sister to A. laticeps (Köhler et al 2015).
The species epithet, “chorus” is from the Latin noun referencing the calling behavior of the species where males call in closely synchronized, large choruses (Köhler et al 2015).
The species was previously referred to as Aglyptodactylus sp. aff. Madagascariensis “East” in 2007 by Glaw and Vences.
Based on ANCOVA analyses of external morophology, A. chorus, A. inguinalis, and A. madagascariensis have only faint and inconsistent differences. This is hypothesized to be due to morphological convergence caused by adapting to the same general habitat (Köhler et al 2015).
IUCN SSC Amphibian Specialist Group. 2016. Aglyptodactylus chorus. The IUCN Red List of Threatened Species 2016: e.84500529A84579483. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T84500529A84579483.en. Downloaded on 22 March 2017.
Köhler, J., Pabijan, M., Glaw, F., Vences, M. (2015). ''Integrative taxonomic revision of mantellid frogs of the genus Aglyptodactylus (Anura: Mantellidae).'' Zootaxa, 4006(3), 401-438.
Written by Amanda Luong (ahluong2 AT dons.usfca.edu), University of San Francisco
First submitted 2018-03-08
Edited by Ann T. Chang (2018-03-08)
Species Account Citation: AmphibiaWeb 2018 Aglyptodactylus chorus <http://amphibiaweb.org/species/8372> University of California, Berkeley, CA, USA. Accessed Dec 13, 2018.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 13 Dec 2018.
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