Hyperolius nasutus Gunther 1865

Hyperolius nasutus Günther, 1865

Large-nosed Long Reed Frog (Fig. 9)

Synonymy. Hyperolius punctulatus (Bocage, 1895)

Genetic material. ZMB 77311 (Calandula, Angola); AC2990 (Kangandala, Angola); LdP field specimen (Xigera, Botswana); SAIAB 186001 (Vumbura, Botswana) (Fig. 1).

Diagnosis. The advertisement call (Fig. 13) consists of a buzz with eight pulses, with a duration of 0.1 s. This distinguishes it from the species with a single unpulsed note, and those with both an initial note and a series of slow pulses: H. adspersus, H. benguellensis, H. friedemanni, H. howelli, H. igbettensis, H. inyangae, H. lupiroensis, H. poweri, H. rwandae sp. nov. and H. viridis. It can be distinguished from the other species that have a buzz call by the number of pulses: 13 pulses in H. dartevellei, 25 pulses in H. acuticeps, and five pulses in H. jacobseni. See Table 3 for a summary of call parameters. The snout is sharply rounded in profile, which distinguishes it from those species with truncated, shark-like, or bluntly rounded snouts: H. adspersus, H. benguellensis, H. dartevellei, H. howelli, H. igbettensis, H. inyangae, H. jacobseni, H. poweri, and H. viridis. The second to fifth toes are webbed to the disc, or just below the disc. This distinguishes it from those species with half or more of a phalanx of the fourth toe free: H. acuticeps, H. benguellensis, H. howelli, H. igbettensis, H. inyangae, H. jacobseni, H. lupiroensis, H. poweri, H. rwandae sp. nov., and H. viridis.

Description of a Vumbura specimen. A male, SAIAB 186001 has the body long and slender, widest at temporal region, slightly tapering to groin; head comparatively small (HL/SUL 0.28, HW/SUL 0.31), not wider than trunk, longer than wide (HL/HW 0.88); snout short (SL/HL 0.30), rounded to trapezium shaped in dorsal view (Fig. 6), (SL/EE 0.53); canthus rostralis fairly distinct, straight-lined from eye to nostril; nostril oval (0.13 X 0.10), directed dorsolaterally; situated much closer to tip of snout than to eye (EN/NS 1.20), separated from each other by distance greater than distance between eye and nostril (NN/EN 1.58); eyes directed anterolaterally, moderately protruding, relatively small (ED/HL 0.46); eye diameter exceeding than snout length (ED/SL 1.50); interorbital distance much wider than upper eyelid (IO/EW 1.91), and greater than internarial distance (IO/NN 2.32); tympanum not visible externally; upper jaw with dentition; choanae small, oval, located far anterolaterally at margins of roof of the mouth, concealed by upper jaw for about the half in ventral view; vomer processes and teeth absent; tongue long, free for about three-fourths of length, bifurcated distally for about one-fourth of length; vocal sac single, median, glandular, pale yellow, roughly triangular;

Dorsal surfaces of head, trunk and limbs finely granulated

Fore limbs slender; hand moderately large (HND/SUL 0.25); tips of fingers enlarged into broad rounded disks; relative finger lengths are I<IV<II<III; subarticular tubercles rounded, well developed, with one on fingers I and II, two on fingers III and IV, with proximal tubercle on fingers III and IV hardly discernible; webbing formula of the hand I 2 +– 2 II 2.5– 2 III 1.5– 2 IV; palmar tubercles absent; metacarpals without supernumerary tubercles; nuptial pads or asperities absent.

Hind limbs slender, moderately long (LEG/SUL 1.48); tibio-tarsal articulation reaching to level of tip of snout when legs are adpressed to body; tibiofibula moderately long (TFL/SUL 0.48), longer than thigh (TFL/THL 1.14); foot shorter than tibiofibula (FOT/TFL 0.70); relative length of toes: I<II<III<V<IV; discs of toes smaller than those of fingers; subarticular tubercles: one on toes I and II, two on toes III and V, and three on toe IV; pedal webbing formula (Fig. 7) I 1 –1.5 II2 –1.5 III 2.5– 2 IV 2.5—2.5 V; inner metatarsal tubercle small, oval, prominent; outer one larger, almost circular, low and less distinct.

Eggs and tadpoles. Unknown.

Colouration in life. Dorsal surface light green, skin more or less translucent. Dorsal surface of body and limbs with very small dark brown to black dots and slightly larger brown to reddish brown specks on dorsum; dots roundish, specks shaped like stars or neurons with many dendrites, limbs green; lateral sides of snout and area above eyes reddish brown, moderately broad dorsolateral stripe running along each side of the body from groin to eye extending to the snout as a thin white line; distal portions of fingers and toes, especially the tips, yellow; ventral side and parts of dorsal side of thigh and upper arm largely unpigmented. Iris reddish-brown. Colouration in preservative. The back is yellow brown with darker uniform speckles that extend on to the upper surfaces of the limbs.

Remarks. Specimens are similar to the type description, and one was collected from the type locality Calandula (Duque de Bragança). The back is covered with small and large spots. The synonymy of H. punctulatus is supported by the spotted back. The species is known from northern Botswana and northern Angola. Due to the extensive range and large population numbers, we suggest that the IUCN status of Least Concern be maintained.