Nectophrynoides uhehe, Thrane & Lyakurwa & Liedtke & Menegon & Petzold & Loader & Scherz, 2025

Thrane, Christian, Lyakurwa, John V., Liedtke, H. Christoph, Menegon, Michele, Petzold, Alice, Loader, Simon P. & Scherz, Mark D., 2025, Museomics and integrative taxonomy reveal three new species of glandular viviparous tree toads (Nectophrynoides) in Tanzania’s Eastern Arc Mountains (Anura: Bufonidae), Vertebrate Zoology 75, pp. 459-485 : 459-485

Nectophrynoides uhehe sp. nov.

Suggested English common name.

Udzungwa glandular tree toad.

Suggested Kiswahili common name.

Chura manundu wa milima ya Udzungwa.

Taxonomic remarks.

This species has previously been referred to as “ Nectophrynoides sp 04 ” by Liedtke et al. (2016).

Holotype.

An adult female specimen in the Natural History Museum of Denmark, Copenhagen, Denmark, ZMUC R 131391 ( M 000044 ), collected 16 th of December 1997 at Kihanga Stream , Uzungwa Scarp N. F. R., Udzungwa Mountains, Iringa Region, Tanzania (approximate coordinates: – 8.37, 35.98) by Mette M. Westergaard (Fig. 7 C ) .

Paratypes.

Series of adults and subadults in the Natural History Museum of Denmark, Copenhagen, Denmark: Adult gravid female ZMUC R 131389 (M 000031), and adults R 131390 (M 000036) and R 131392, all with the same collection data as the holotype. Adult ZMUC H 001955 ( R 970529 ), collected 26 th of May 1997 in Kihanga Stream , Uzungwa Scarp N. F. R., Udzungwa Mountains, Iringa Region, Tanzania ( –8.3683, 35.9783) at 1750 m a. s. l. by David C. Moyer in primary montane forest . Series of adults in the Museo Tridentino di Scienze Naturali, Trento, Italy: MUSE 5247 ( MTSN 5247 ), 5248 ( MTSN 5248 ) and 5249 ( MTSN 5249 ) collected between 4 th and 19 th of January 1999 in Kihanga , Uzungwa Scarp N. F. R., Udzungwa Mountains, Iringa Region, Tanzania ( –8.3733, 35.9786) at 1800 m a. s. l. by Michele Menegon in a closed canopy montane rain forest .

Definition.

A member of the Nectophrynoides viviparus species complex based on overall body proportions, glandular limbs and large parotoid glands (Fig. 11 ), as well as genetic affinities based on mitochondrial markers (Fig. 1 ). This species is characterised by the unique combination of the following set of characters: (1) distinct glandular masses on limbs; (2) large body size (adult SUL 17.2–52.5 mm, mean 29.83 ± 8.61 mm); (3) expanded, rounded finger and toe tips with small discs; (4) parotoid gland not continuous with dorsal orbit, kidney shaped; (5) relative head width ( HW / SUL) 0.33–0.42; and (6) relative head length ( HL / SUL) 0.32–0.41.

Diagnosis.

Nectophrynoides uhehe sp. nov. can be distinguished from N. asperginis , N. cryptus , N. frontierei , N. laevis , N. laticeps , N. minutus , N. paulae , N. poyntoni , N. pseudotornieri , N. tornieri , N. vestergaardi and N. wendyae by its very large body size and having large, distinct glandular masses on limbs (versus indistinct or absent).

Nectophrynoides uhehe sp. nov. is distinguishable from N. viviparus sensu stricto by its larger body size ( SUL 17.2–52.5 mm vs 18.8–37.2 mm) and having more expanded, distinct limb and parotoid glands. The shape of finger- and toe tips of N. uhehe sp. nov. are more expanded than N. viviparus sensu stricto, which has more slender and rounded fingers. The parotoid glands are not continuous with the dorsal orbits, they are large and protruding, forming a rough kidney shape (Fig. 9 C ), whereas the parotoid glands of N. viviparus sensu stricto are continuous with the dorsal orbits, they are smaller and less protruding, forming a rough fusiform shape (Fig. 9 A ).

Nectophrynoides uhehe sp. nov. is distinguishable from N. luhomeroensis by a larger maximum body size ( SUL 17.2–52.5 mm vs 18.4–30.0 mm) and less distinct glandular limbs, and kidney-shaped and more pronounced parotoid glands (Fig. 9 C ) (vs rhomboid and less pronounced; Fig. 9 B ).

For distinction from N. saliensis sp. nov., refer to the diagnosis of that species, below.

Generalised description.

A large and robust Nectophrynoides with relatively short, muscular and very glandular limbs. The snout shape is triangular with a rounded tip, extending slightly beyond the upper lip. The canthus rostralis is slightly concave and flattened. The tympanum is distinct. The parotoid glands are distinct and continuous with the dorsal orbits. The parotoid glands extend from the posterior end of the eyes to above the arm insertion in the scapular region forming a rough kidney shape (Fig. 9 C ). The body has medium sized irregular glandular bumps and patches scattered across the dorsal and lateral surfaces. The limbs with distinct and expanded glandular masses. The hindlimb is more than twice as long as the forelimb. The length of the foot is greater than the length of the tibia. The hands and feet with rudimentary webbing. The finger and toe-tips are expanded and rounded.

In preserved specimens, the colouration and patterning are highly variable. The ground colour is caramel to very dark tawny brown with cream to tawny brown glandular bumps and patterning. Several specimens with large amounts of patterning in different shapes and sizes of variable colours from white to dark tawny brown. The glandular masses on limbs and the parotoid glands are cream to tawny brown with no patterning, or with caramel to dark tawny brown patterning.

Description of holotype.

ZMUC R 131391 (M 000044), an adult female. All measurements are given in mm. Large and robust specimen ( SUL: 45.2, SVL: 47.7). Width of head ( HW: 17.6) greater than length of head ( HL: 16.7). Lower jaw rounded in dorsal and ventral profile with flattened and blunted snout. Very wide triangular snout and very slightly rounded anteriorly. In lateral profile, anterior end of snout is level with bottom of eye. Nostrils situated on either side of snout, at level of eye centre ( ND: 4.3), and clearly visible dorsally. Eyes relatively large and bulging in dorsal profile ( ED: 5.0). Distance between eye and naris ( END: 3.3) greater than distance between naris and tip of snout ( NSD: 2.4). In lateral profile, eye and dorsal orbit continuous with anterior end of snout to posterior end of eye. Canthus rostralis flattened and loreal region slightly concave from top of canthus rostralis to edge of upper jaw. Canthus rostralis visible in dorsal profile. Tympanum and tympanic annulus distinct and rounded. Horizontal diameter of tympanum ( TYMP: 1.7) almost 1 / 3 of horizontal diameter of eye. Forelimbs muscular and relatively short. Forearm longer than humerus ( FOL: 11.7, HUL: 8.7), hand longest ( HAL: 15.0). Outer metacarpal tubercle length almost equal to width ( OMCL: 2.3, OMCW: 2.4), inner metacarpal tubercle shortest ( IMCL: 1.8). First fingertip less expanded ( F 1 W: 1.1) than third fingertip ( F 3 W: 1.3). Hindlimbs muscular and relatively long. Tibia and thigh almost equal in length ( TIL: 19.6, THL: 19.9), almost twice as long as metatarsus ( ML: 11.6), foot longest ( FL: 24.3). Outer metatarsal tubercle length ( OMTL: 2.2) shorter than inner metatarsal tubercle ( IMTL: 2.9). First and fourth toe tip equally expanded ( T 1 W: 1.2, T 4 W: 1.2). Hindlimbs more than twice as long as forelimbs ( HIL: 75.3, FORL: 35.4).

Skin texture smooth on glandular and non-glandular surfaces. Dorsal head glandular with small pores. Dorsal orbits glandular with large pores. Dorsum with large, irregular, circular glandular bumps. Dorsal surface of limbs with distinct glandular masses. Humerus and femur with irregular glandular masses. Forearm, hands, tibia, metatarsus and feet have distinct, swollen glandular masses with large pores. Parotoid glands paired and continuous with dorsal orbits. Parotoid glands with large pores and spongy texture. Parotoid glands situated from posterior to eye to scapular region above arm insertion. Parotoid glands rough and asymmetrical kidney shape, widest posterior to tympanum above angle of jaw and narrows to a point above arm insertion. Parotoid glands extend to lateral surface of tympanic region posterior to tympanum and narrows before arm insertion. Lateral head consists of irregular patches of glandular and non-glandular skin. Canthus rostralis has glandular skin with small pores. Posterior and inferior surface of tympanum to posterior end of eye has 25 medium to large glandular masses each with a small translucent spine. Flank without glandular patches. Ventral surfaces non-glandular except femoral area with small, raised bumps. Fingers and toes stout with expanded and rounded digits. Hands and feet with distinct, raised tubercles and rudimentary webbing. Feet slightly more webbed extending slightly beyond the first subarticular tubercles.

Dorsal ground colour tawny brown. Head caramel brown. Dorsum tawny brown with large caramel brown raised circular glandular masses. A dark tawny brown indistinct and broken dorsal stripe runs from snout to cloaca. Tawny brown glandular masses on humerus and femur. Parotoid glands and glandular masses on limbs, hands and feet cream to caramel brown. Fingers and toes cream. Flank dark tawny brown. Lateral head tawny brown with cream and caramel brown patches. Nostrils caramel brown. Canthus rostralis, upper and lower lip cream. Dorsal orbits bluish ash grey. Abdomen dark tawny brown. Pectoral region and chin tawny brown with indistinct cream and caramel brown spots. Ventral surface of hands and feet tawny brown with cream tubercles, fingers and toes. Ventral surface of forelimbs dark tawny brown and hindlimbs tawny brown. Femoral area tawny brown with caramel brown bumps.

No photographs or field notes describing colouration of holotype in life are currently known.

Variation in the species.

MUSE 5247 , 5248 and 5249 with irregular patterns and spots covering dorsal and ventral surfaces with white blotches on head, chin, back, abdomen, flank, limbs, hands and feet. ZMUC R 131389, R 131390 and R 131392 are smaller ( SUL: 22.79–26.94 vs 45.22) with more slender fingers and toes, and less distinct glandular masses on limbs, hands and feet. There is a large variety in colouration and patterning between individuals (Fig. 11 ). Sexual dimorphism was not observed in preserved material, but females are expected to be larger than males, like congeners.

Preservation status.

The holotype and paratypes are in good condition.

Genetics.

Paratypes MUSE 5248 and 5249 have been successfully sampled and sequenced ( Liedtke et al. 2016). Nectophrynoides uhehe sp. nov. is genetically distinct according to Liedtke et al. (2016), who used species delimiting approaches (specifically bGYMC) to examine current bufonid diversity against undescribed diversity. In their analysis, N. uhehe sp. nov. was genetically distinct and identified as “ Nectophrynoides sp 04 ”. The specimen used in the analysis done in Liedtke et al. (2016) was MHNG 2609.071 (field number TZ- 088), which is effectively 100 % genetically identical to paratype MUSE 5249 . MUSE 5249 is at least 3.13 % genetically different in partial (ca. 550 bp) 16 S rRNA from all other Nectophrynoides , with the closest relative being N. luhomeroensis sp. nov. (see Table 3 ). This is rather at the inter-specific level than the infra-specific (population) level; the infra-specific distance between sequenced specimens is 0–0.481 %.

Bioacoustics.

The call analysis was carried out on two audio files both consisting of 11 calls with a mean of 25.27 pulses per call in each file. The two calls were recorded in January 1999 in Site 5, Mkaja, Uzungwa Scarp N. F. R., Udzungwa Mountains, Tanzania ( –8.3420, 35.9671) at 1800 m a. s. l. by Michele Menegon in an open montane wetland consisting of an ecotone between bamboo forest and open wetland ( Menegon and Salvidio 2005). The two calls are not associated with any known specimens. However, the two calls were recorded nearby to the type locality. Therefore, we assume that these calls are suitable representatives of Nectophrynoides uhehe sp. nov. A singular audio file containing calls of this species deposited online ( https://doi.org/10.5281/zenodo.17277236).

The two calls were practically identical in all aspects of their call parameters. We cannot confirm whether these are of one or two individuals. The calls consist of a sequence of 16–30 pulses per call (Fig. 6 B ). The mean call duration is 0.28 ± 0.03s (range: 0.22– 0.32s), with a mean call interval of 3.24 ± 1.27s (2.10– 5.95s). Each call contains a mean of 25.27 ± 3.66 pulses (16–30), with a mean pulse duration of 0.011s + / – 0.001s ( 0.011 – 0.014s). The mean dominant frequency is 1891.64 ± 7.17 Hz (1883–1904 Hz). The call structure is illustrated in a spectrogram and waveform in Fig. 6 B .

The male advertisement call is monophasic consisting of pulse trains of similar proportions. The first pulse has the highest intensity followed by a series of pulses that slowly decreases in intensity. The two recordings show remarkable resemblance, with almost identical results. It is worth noting that both call series begin by a pulse train that has a significantly lower number of pulses. The background noises from the habitat, people talking, and other interferences indicate that these two individual call series were taken separately and illustrate a remarkable consistency within the call structure of this species.

The few recordings highlight the need for further field research and analysis of the bioacoustics in the Nectophrynoides viviparus species complex. We can therefore only hint at the possibility that the call of N. uhehe sp. nov. is distinctive, and easily distinguishable from other Nectophrynoides species in the field. The call of the new species is distinct from N. viviparus sensu stricto which has fewer pulses in each pulse train (mean is ~ 13 pulses), and a longer duration between calls (Fig. 6 A ). For the statistical analysis between the two species see Table 2 . However, the low number of recordings result in uncertainty regarding the actual difference between calls. More behaviour studies and recordings need to be made in the field to rule out certain factors that could shape the calls such as close vicinity with high competition between males, stress calls, and simplified communicational calls.

Etymology.

The species Nectophrynoides uhehe sp. nov. is named in honour of the indigenous Hehe tribe, who live in villages surrounding the forests where the species occurs, for their support / involvement in herpetological surveys in the area. The Swahili word “> uhehe ” indicates something with affinity to the Hehe tribe. The suggested common name is a reference to the distribution of this species across the Udzungwa Mountains, its glandular skin, and semi-arboreal lifestyle.

Habitat and life history.

Specimens have been collected in several forest fragments across the Udzungwa Mountains, including Kigogo F. R., Kiolela F. R., Kitungulu F. R., Mufindi Scarp F. R., Uzungwa Scarp N. F. R., and Kilombero N. F. R. The type specimens were collected in closed canopy montane rainforest between 1700 and 1800 m a. s. l. near Kihanga stream inside Uzungwa Scarp N. F. R. (Fig. 12 ). The presence of developed toadlets inside several adult female specimens suggests that this species is ovoviviparous, as in its congeners. More recent observations are known by John Lyakurwa, Michele Menegon and Elena Tonelli in 2014–2016 at multiple locations within the Uzungwa Scarp N. F. R. from 1600 m a. s. l. Individuals were observed on the ground, around small wetlands both inside and bordering the forest, and some specimens were observed up to 2 m above the ground on understory vegetation in the moist forest inside closed canopy montane rainforest.

Figures

Figure 1. Maximum likelihood phylogeny of glandular tree toads inferred from the three mitochondrial markers (Nectophrynoides viviparus complex). ModelFinder recovered three partitions of the data (Partition 1: 12 S, 16 S - TPM 2 u, Partition 2: COI _ p 1, COI _ p 2 - HKY, Partition 3: COI _ p 3 - TIM 2). Branch supports refer to bootstrap values, and branch lengths represent the number of nucleotide substitutions per site (see scale bar). Nectophrynoides species not part of the N. viviparus complex are shown in grey, and type material for which sequence information was obtained via museomics are shown in orange. Heatmap inset shows mean uncorrected 16 S genetic pairwise distances.

Figure 6. Pulse train arrangement and frequency landscape of A Nectophrynoides viviparus sensu stricto from Mdandu, Livingstone Mountains; B N. uhehe sp. nov. from Uzungwa Scarp N. F. R., Udzungwa Mountains. Plots from top to bottom show: frequency spectrum (FFT function width = 128, linear scale, Hann Window); spectrogram; and waveform (pulse train). Spectrogram and waveform are shown over the duration of a call (0–0.35 s).

Figure 7. Comparative photographs of lectotype and holotypes. For each specimen, dorsal (left), lateral (centre), and ventral (right) views are shown. A Lectotype of Nectophrynoides viviparus sensu stricto (ZMB 21775); B holotype of N. luhomeroensis sp. nov. (BM 1983.6; KMH 2438); C holotype of N. uhehe sp. nov. (ZMUC R 131391; M 000044); D holotype of N. saliensis sp. nov. (MUSE 13758; KMH 26644). Scale bar: 10 mm.

Figure 9. Comparative illustration of parotoid glands of Nectophrynoides viviparus sensu stricto and the new species described herein, shown in dorsal view. A Paralectotype of Nectophrynoides viviparus sensu stricto (ZMB 84909); B paratype of N. luhomeroensis sp. nov. (MTSN 8312); C paratype of N. uhehe sp. nov. (ZMUC H 01955; R 970529); D holotype of N. saliensis sp. nov. (MUSE 13758; KMH 26644). Illustrations by Simon P. Loader.

Figure 11. Intraspecific variation within Nectophrynoides uhehe sp. nov. in life. A Adult paratype MTSN 5247; B – D unidentified adult specimens. Photographs from Kihanga (A, B, C) and Kiolela (D) in Uzungwa Scarp N. F. R., Udzungwa Mountains by Michele Menegon.

Figure 12. Habitat of Nectophrynoides uhehe sp. nov. in Kihanga, Uzungwa Scarp N. F. R., Udzungwa Mountains. Photograph by Michele Menegon.