Amnirana adiscifera ( Schmidt and Inger, 1959 ) Conradie & Keates & Verburgt & Baptista & Harvey, 2023

Conradie, Werner, Keates, Chad, Verburgt, Luke, Baptista, Ninda L. & Harvey, James, 2023, Contributions to the herpetofauna of the Angolan Okavango- Cuando-Zambezi river drainages. Part 3: Amphibians, Amphibian & Reptile Conservation (e 325) 17 (1), pp. 19-56 : 49-50

Amnirana adiscifera ( Schmidt and Inger, 1959) stat. nov. Green White-lipped Frog ( Fig. 38 ; Map 37 )

Material (18 specimens, 5 tadpole lots): PEM A11599 , Cuito River source lake, -12.68935° 18.36012°, 1,431 m asl ; PEM A12447 , Cuanavale River source lake, -13.08537° 18.89098°, 1,360 m asl ; PEM A12726 , Cuando River source, -13.00346° 19.12751°, 1,353 m

asl; PEM A12727–8, Cuando River source, -13.00346° 19.12751°, 1,353 m asl; PEM A12764–6, Cuando River source, trap 1, -13.00393° 19.12808°, 1,351 m asl; PEM A12791, Cuanavale River source lake camp side, -13.09442° 18.89370°, 1,368 m asl; PEM A12798–9, Cuanavale River source lake opposite side, -13.08934° 18.89485°, 1,359 m asl; PEM A12842, west of Cuito town on Aludungo road, -14.64833° 16.97444°, 1,380 m asl; PEM A13736 (tadpoles), Comba River, -12.62442° 18.65159°, 1,299 m asl; PEM A13764, Lungwebungu River old oxbows, -12.58129° 18.67162°, 1,304 m asl; PEM A14082 (tadpoles), Luissinga River, -14.58899° 18.44367°, 1,311 m asl; PEM A14091 (tadpoles), Cuanavale River source, -13.09033° 18.89396°, 1,359 m asl; PEMA 14099 (tadpoles), PEMA 12485–7, Dala River, near Samanga village, -12.93169° 18.81458°, 1,363 m asl; PEM A14121 (tadpoles), Culua River source, 6 km SE of Cuito River source, -12.73675° 18.39310°, 1,446 m asl; PEM A14679, Menongue, -14.63015° 17.63465°, 1,373 m asl; PEM A14716, Cuanavale River source lake, -13.09052° 18.89394°, 1,357 m asl. Additional material (14 specimens, 4 tadpole lots): SAIAB 209135 (5 specimens), Kalilongue Dam inflow, -12.44722° 16.82428°, 1,429 m asl; SAIAB 209081 (1 specimen), swamp near Cuanavale River source, -13.10750° 18.86089°, 1,386 m asl; SAIAB 209080 (tadpoles), Cuito River source outlet, -12.70455° 18.35203°, 1,430 m asl; SAIAB 209088 (tadpoles), Calua River lagoon, -12.73599° 18.39394°, 1,448 m asl; SAIAB 209140 (tadpoles), Cuanavale River lake outlet, -13.09414° 18.89612°, 1,357 m asl; SAIAB 204541 (tadpoles), Cuanavale River source lake below fish fence, -13.09364° 18.89597°, 1,357 m asl; SAIAB 204567 (1 specimen), Quembo River source lake, -13.13611° 19.04500°, 1,363 m asl; SAIAB 204520 (2 specimens), SAIAB 204531 (1 specimen), SAIAB 204534 (1 specimen), Cuanavale River source lake, -13.08997° 18.89389°, 1,358 m asl; SAIAB 204484 (1 specimen), stream outflow about 2.6 km downstream of Cuando River source lake, -13.00317° 19.15153°, 1,333 m asl; SAIAB 204496 (2 specimens), river at Munhango lagoon, -12.17281° 18.54897°, 1,376 m asl. Description: Large ranid; large tympanum, nearly equal in size to eye; elevated upper lip ridge from snout tip to above arm; pair of dorsolateral ridges from eye to urostyle; some specimens have a small flap or ridge above the vent; smooth elevated subarticular tubercles on feet; small indistinct outer metatarsal tubercle, inner metatarsal tubercle present; pedal webbing formula: I (1), II i/e (1-2), III i/e (1-3), IV (2-3), V (1); no dilated toe tips or terminal discs, no horizontal grooves present on toe tips; no external vocal sacs. All the adults collected were green and not the typical golden-brown coloration as illustrated in Du Preez and Carruthers (2009). Metamorphs retain dorsal and ventral spots, which fade during growth. Tadpoles are orange with black scattered dots. Males with a small nuptial pad on the thumb and enlarged glands on the upper arm. Adult females (n = 7) varied from 57.0–66.5 (61.6) mm (largest female: PEM A14716); adult males (n = 6) varied from 46.9–62.4 (55.0) mm (largest male: PEM A12799). Habitat and natural history notes: Males called in late afternoons and early evenings, from vegetation on the edge of open deep waters. Comments: Currently, five species of Amnirana have been recorded from Angola ( Marques et al. 2018; Baptista et al. 2019): A. albolabris , A. darlingi , A. lemairei , A. lepus , and A. parkeriana . All except A. darlingi are forest-associated species, with toes that are dilated or have discs with horizontal grooves. The specimens found in our study do not exhibit dilated toes or terminal discs. Five specimens from Chitau that were initially referred to as Rana albolabris (see Schmidt 1936), were later described as Rana albolabris adiscifera by Schmidt and Inger (1959). Those authors only compared it to R. albolabris and R. a. lemairei , and differentiated it based on the condition of the toes (no dilated tips or discs), webbing (reduced versus extensive) and foot length (long versus short), respectively. Later, without much explanation, Laurent (1964) synonymised it with Rana darlingi [= Amnirana darlingi ], and this was followed by Poynton (1964) and Perret (1977). Jongsma et al. (2018) showed that eastern ( Malawi) and western (Angolan) A. darlingi material differ significantly enough on a molecular level to warrant taxonomic re-evaluation. However, no taxonomic action has been undertaken pending more evidence. The type locality of A. darlingi is ‘Mazöe and between Umtali [Mutare] and Marandellas [= Marondera], Mashonaland, Zimbabwe’ and represents the eastern material of Jongsma et al. (2018). The new series of specimens is in full morphological agreement with the description of R. a. adiscifera . However, no coloration details were provided in the original description or in Schmidt (1933). The newly collected material agrees in preserved coloration and morphology to photos of the holotype (https://collections-zoology. fieldmuseum.org/catalogue/1848393). The green Angolan form of A. darlingi is also in agreement with the green ‘undescribed Hillwood frog’ referred to by Channing (2001) and Channing and Rödel (2019). Recently, Ceríaco et al. (2016, 2018) also documented this green form of A. darlingi from central Angola. Based on the color differences, together with the typical form (green versus brown) and the genetic results by Jongsma et al. (2018), we here formally assign the green western material to Schmidt and Inger’s (1959) adiscifera and elevate it to full species, Amnirana adiscifera stat. nov. This species is widely distributed in central Angola and northwestern Zambia (see Channing 2001; Channing et al. 2013; Marques et al. 2018; Channing and Rödel 2019). Similar distribution patterns have been observed in Kassinula wittei , Kassina kuvangensis , as well as the snake Limnophis bicolor ( Conradie et al. 2020a,b; this study). Amnirana can be divided into two morphotypes: those with short feet, dilated toes, or terminal discs and extensive webbing ( albolabris , amnicola, asperrima, fonensis, lemairei , lepus , occidentalis, and parkeriana ), and those with long feet, reduced webbing, and no dilated toes or discs ( adiscifera , darlingi , and galamensis). The former group is restricted to forests, while the latter prefers flooded grasslands in savanna ( Poynton 1964). However, this pattern is not mirrored in the phylogenetic analysis, and indicates that adaptation from savanna to forest has occurred more than once ( Jongsma et al. 2018).

Figures

Map 37. Distribution of Amnirana adiscifera stat. nov. in Angola.

Fig. 38.Adult male Amnirana adiscifera stat. nov. from Cuando River source. Photo by James Harvey.