AMPHIBIAWEB
Nectophrynoides poyntoni
Poynton’s Forest Toad
family: Bufonidae
 
Species Description: Menegon M, Salvidio S, Loader SP 2004 Five new species of Nectophrynoides Noble 1926 (Amphibia Anura Bufonidae) from the Eastern Arc Mountains, Tanzania. Trop. Zool. 17:97-121
Conservation Status (definitions)
IUCN (Red List) Status Critically Endangered (CR)
CITES Appendix I
Other International Status None
National Status None
Regional Status None

 

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Description
Nectophrynoides poyntoni is a medium sized frog with a snout-urostyle length range in males from 19.1 – 24.0 mm and with two female specimens measuring 20.2 and 23.9 mm. The holotype head width is 8.5 mm, measured at the jaw articulation. The snout is short with the nostrils being closer to the tip of the snout that the eyes. The eyes are pronounced, can be seen from the ventrum view, and have horizontal pupils. A tympanum is present and clearly visible. There is also a tympanic annulus. The parotoid glands form a row of small glands on the anterior side that lead antero-posteriorly to a large posterior parotoid in the scapular region that is twice as long as it is wide. The posterior parotoid is about the same length as the eye. The limbs are narrow. This species lacks webbing on the fingers, and only the fourth and fifth toes are webbed. Both the fingers and the toes have rounded tips. The tibia is longer than the foot. The feet are characterized by two white tubercles of similar size on the metatarsal region. This species is textured with microscopic warts, or coni, throughout the body skin. Distinct scapular parotid glands are present, and are noticeably larger than other glands on the dorsum. There is no indication of sexual dimorphism in this species (Menegon et al. 2004).

Nectophrynoides poyntoni is similar in body shape and size to N. tornieri and to N. vestergaardi. However, in contrast to the expanded and truncate fingers and toes of N. tornieri, N. poyntoni has rounded toes. In addition, the two species can be easily differentiated by their advertisement calls. From N. vestergaardi, a species that also has rounded tips on its digits, the parotid gland shape, hind and forelimb ratios, and the dorsal pattern may all be used to discern these two species. From N. viviparous, the focal species can be differentiated by the latter lacking large glands on the limbs and being smaller in size. Nectophrynoides asperginis, N. laevis, N. pseudotornieri, N. wendyae and N. cryptus do not have an obvious tympanum, which makes them distinguishable from N. poyntoni. While the tympanum is occasionally visible in N. cryptus, the presence of a longer foot than tibia separates N. cryptus from N. poyntoni. The larger body size and pronounced bicolored parotid gland distinguishes N. poyntoni from N. minutus and N. frontierei (Menegon et al. 2004).

It is unclear if the coloration described by the species authority is in life or in preservative. The dorsal surface of the holotype specimen is primarily various shades of brown. Scattered, darker blotches are common. A black stripe is present from the tip of the snout to the end of the parotid glands. A light brown mid-dorsal stripe with a black outline is present. Beige coloration occurs on the sides of the head, the upper arms, and the dorsal surface in an upside-down “v” shaped marking, outlined in black. The dorsal glands have concentrations of melanophores on pale pink areas in the pattern of interrupted stripes. The ventral surface is gray with a few melanophores (Menegon et al. 2004).

The dorsal pattern varies between specimens. The coloration may be mostly shades of brown, or many darker/black blotches may be present on the dorsal surface of the head, body and legs. Dark, possibly interrupted, stripes may also run from the snout to the scapular parotoids or along the vertebral line (Menegon et al. 2004).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Tanzania, United Republic of

 

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Nectophrynoides poynton is endemic to the Udzungwa Scarp Forest Reserve (200 km2) in the Iringa Region of southern Tanzania at elevations of 1,200 m. The forest is located on the south-eastern slopes of the Udzungwa Mountains, which is part of the Eastern Arc mountain chain. The habitat of N. poyntoni is submontane rain forest. The emergent layer reaches 50 m in this area, and the canopy is 30 to 40 m high. This species, as well as N. tornieri, was common along the Mkalazi stream when it was described (Menegon et al. 2004, Menegon and Salvidio 2005).

Life History, Abundance, Activity, and Special Behaviors
Nectophrynoides poyntoni is active during the evening on leaves 60 – 160 cm above the ground. During the day they could be found in hiding places under fallen trees and large pieces of wood (Menegon et al. 2004).

Nectophrynoides poyntoni is inferred to be an ovoviviparous or lecithotrophic species due to their small clutches of large, yolky eggs (Liedtke et al. 2014; Menegon et al. 2004). Menegon et al. (2004) reported clutch sizes of 8 and 10 large, yolky eggs in dissected specimens.

Menegon et al. (2004) describe the advertisement call of a male N. poyntoni. Males call near streams and vegetation in the late afternoon or after sunset. The monophasic call consists of high-pitched notes in a series of pulse trains. Each pulse lasts for 60 ms, and has a dominant frequency of 2.9 kHz and a second harmonic is emphasized at 8.7 kHz. The inter-pulse duration is 80 ms. A single pulse train has a duration of 1 s (6 - 8 pulses), and the interval between pulse trains is 2.5 - 3.5 s. The high frequency of the call may help distinguish the call from the noise of low frequency water turbulence.

Nectophrynoides poynton co-occurs withN. tornieri, which is similar in size and shape, but can differentiated based on toe-tip shape and advertisement call (Menegon et al. 2004).

Trends and Threats
Nectophrynoides poyntoni is a hyper-endemic and very rare frog species from the Uzungwa Scarp Forest Reserve (Barratt et al. 2014). It is listed as “Critically Endangered” on the IUCN Red List and is threatened by habitat loss. The N. poyntoni population is said to be declining, but this species may already be extinct (IUCN 2015).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities

Comments
The species authority is: Menegon, M., Salvidio, S., and Loader, S.P. (2004). “Five new species of Nectophrynoides Noble 1926 (Amphibia Anura Bufonidae) from the Eastern Arc Mountains, Tanzania.” Tropical Zoology, 17(1), 97-121.

The species epithet “poyntoni” was named in honor of Professor John Poynton (Menegon et al. 2004)

References

Barratt, C., Tonelli, E., Menegon, M., Doggart, N., Bowkett, A., Harris, W.E., Howell, K., Ngalason, W., Loader, S. (2014). ''Fragmented habitats and species: The challenges of amphibian conservation in Tanzania today.'' FrogLog, 22(111), 63-64.

IUCN SSC Amphibian Specialist Group. (2015). Nectophrynoides poyntoni. The IUCN Red List of Threatened Species 2015: e.T54842A13323022. http://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T54842A13323022.en. Downloaded on 15 June 2016.

Liedtke, H.C., Müller, H., Hafner, J., Nagel, P., and Loader, S. (2014). ''Interspecific patterns for egg and clutch sizes of African Bufonidae (Amphibia: Anura).'' Zoologicher Anzeiger, 253(4), 309-315.

Menegon, M., Salvidio, S., and Loader, S. P. (2004). ''Five new species of Nectophrynoides Noble 1926 (Amphibia Anura Bufonidae) from the Eastern Arc Mountains, Tanzania.'' Tropical Zoology, 17, 97-121.



Written by Melissa Headley (mheadley AT rams.colostate.edu), Colorado State University
First submitted 2017-03-01
Edited by Ann T. Chang (2017-03-02)

Species Account Citation: AmphibiaWeb 2017 Nectophrynoides poyntoni: Poynton’s Forest Toad <http://amphibiaweb.org/species/6336> University of California, Berkeley, CA, USA. Accessed Oct 20, 2017.



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Citation: AmphibiaWeb. 2017. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Oct 2017.

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