Hyperolius nasicus Laurent, 1943

Channing, A., Hillers, A., Lötters, S., Rödel, O., Schick, S., Conradie, W., Rödder, D., Wagner, P., Dehling, J. M., Du Preez, L. H., Kielgast, J. & Burger, M., 2013, Taxonomy of the super-cryptic Hyperolius nasutus group of long reed frogs of Africa (Anura: Hyperoliidae), with descriptions of six new species, Zootaxa 3620 (3), pp. 301-350 : 333-334

Hyperolius nasicus Laurent, 1943

Pointed long reed frog ( Fig. 12 )

Genetic material. SAIAB A-136-1 (2 specimens, Elephant's Camp, Mozambique); SAIAB A-188 (Satellite Camp, Mozambique); SAIAB KU95952, KU96401, KU98212 (Quantum Mine & Kalumbila River, Zambia); ZMB 77308 (Kisanfu River, DRC); ZMB 77309 Fungurume, DRC; ZMB 77310 (Nyanga Flats, Zimbabwe); ZMB 77301–2, 77304–7, 77314 Ikelenge, Zambia.

Diagnosis. The advertisement call ( Fig. 11 ) consists of a brief chirp-like note of about 10–20 constant-rate pulses with a duration of 0.09– 0.2 s. It can be distinguished from species producing only a single note, and those producing only a buzz: H. acuticeps , H. adspersus , H. dartevellei , H. jacobseni , H. lamottei , and H. lupiroensis It differs from species producing a call over 0.2 s: H. benguellensis , H. inyangae and H. viridis . It differs from the species that have a number of slower pulses: H. friedemanni , H. igbettensis H. howelli and H. poweri . The call is similar in structure to that of H. nasutus , but the latter call has a shorter duration and a higher pulse rate. See Table 3 for a summary of call parameters. The snout is sharply rounded from above, with a shark-like tip when viewed from the side, which distinguishes it from those species without truncated, shark-like, or bluntly rounded snouts: H. adspersus , H. dartevellei , H. friedemanni , H. howelli , H. igbettensis , H. inyangae , H. jacobseni , H. lamottei , H. lupiroensis , H. nasutus , H. poweri , H. rwandae and H. viridis . The first, third and fifth toes have one phalanx free of webbing, distinguishing it from all the other species. Measurements of some individuals are compared with the other species in Appendix 2.

Description of a Nyanga Flats specimen. This is a male (ZMB 77310). Body long and slender, widest at midbody, slightly tapering to groin; head comparatively small (HL/SUL 0.32, HW/SUL 0.27), not wider than trunk, longer than wide (HL/HW 1.22); snout long (SL/HL 0.45), pointed in dorsal view, acute in profile ( Fig. 6 ), with a slightly upturned tip, considerably projecting beyond lower jaw, wider than long (SL/EE 0.78); canthus rostralis distinct, sharply rounded, almost straight-lined from eye to just beyond nostril, slightly convex near tip of snout; loreal region almost vertical, slightly concave; nostril directed dorsolaterally; situated much closer to tip of snout than to eye (EN/NS 1.7), separated from each other by distance equal to distance between eye and nostril (NN/EN 1.0); eyes directed anterolaterally, moderately protruding, relatively small (ED/HL 0.27); eye diameter less than snout length (ED/SL 0.61); interorbital distance subequal to upper eyelid (IO/EW 1.04), and greater than internarial distance (IO/NN 1.41); tympanum not visible externally; upper jaw with dentition; teeth on premaxilla larger than those on maxilla; choanae small, oval, located far anterolaterally at margins of roof of the mouth; vomer processes and teeth absent; tongue long 5.4, and narrow (2.2 at widest point), free for about three-fourths of length, bifurcated distally for about one-third of length; median lingual process absent; vocal sac single, median, subgular; gular flap consisting of thickened skin; anterior part cream-coloured, larger, more granular, and thicker than posterior whitecoloured part; vocal sac aperture on each side of the mouth, situated lateral from and close to base of tongue, slitlike, long.

Dorsal surfaces of head, trunk and limbs generally smooth; ventral surface of limbs and gular smooth, chin and abdomen slightly more areolate.

Fore limbs slender; hand moderately large (HND/SUL 0.28); tips of fingers enlarged into broad oval disks, each with circummarginal groove; relative length of fingers: I<II<IV<III; subarticular tubercles rounded, well developed, with one on fingers I and II, two on fingers III and IV, with proximal tubercle on finger IV hardly discernible; webbing formula of the hand I 2– 2 II 2– 3 III 2.5–2.5 IV; thenar tubercle indistinct, low; palmar tubercles absent; metacarpals without supernumerary tubercles; nuptial pads or asperities absent.

Hind limbs slender, moderately long (LEG/SUL 1.41); tibio-tarsal articulation not 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); heels overlapping each other considerably when knees are flexed and thighs are held laterally at right angle to body; foot shorter than tibiofibula (FOT/TFL 0.84); 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 II 0.5– 1 III 1– 1 IV 1– 1 V; inner metatarsal tubercle small, oval, prominent; outer one indistinct.

Colouration in life. Generally weakly pigmented. The frog was translucent green, with the pale dorsolateral bands originating at the snout tip. A thin dark middorsal line runs from the snout tip to between the eyes. The iris is dark brown. Colouration in preservative. The back is pale yellow with dense small dark chromatophores. The pale dorsolateral bands originate at the nostril, run over the eye and continue to the groin. They are not bordered. A darkly pigmented band runs from the nostril to the eye. Ventrally unpigmented.

Eggs and tadpoles. Unknown.

Habitat. This species has been found in open savanna, through densely vegetated areas along the Congo River, to flooded swamp forest. They call from emergent vegetation bordering pools or flowing water up to a meter above the water surface.

Distribution. This species has been confirmed on molecular data from Mozambique, north-western Zambia, eastern Zimbabwe and Democratic Republic of Congo ( Fig. 1 ).

Figures

FIGURE 1. Map showing the distribution of the sequenced specimens of recognised species in the Hyperolius nasutus group plus H. lamottei. Species numbers represent the following: 1 — H. acuticeps, 2 — H. adspersus, 3 — H. benguellensis, 4 — H. friedemanni sp. nov., 5 — H. howelli sp. nov., 6 — H. igbettensis, 7 — H. inyangae sp. nov., 8 — H. jacobseni sp. nov., 9 — H. lamottei, 10 — H. lupiroensis sp. nov., 11 — H. nasutus, 12 — H. poweri, 13 — H. rwandae sp. nov., 14 — H. dartevellei, 15 — H. viridis, 16 — H. nasicus.

FIGURE 6. Snout profiles of representatives of the species in the Hyperolius nasutus group.

FIGURE 7. Webbing diagrams of representatives of the species in the Hyperolius nasutus group.

FIGURE 11. Advertisement calls of H. jacobseni Gatiko (left), H. lamottei Nimba (center left), H. lupiroensis Lupiro (center right) and H. nasicus Fungurume (right).

FIGURE 12. Hyperolius igbettensis, Lamto, Ivory Coast, photo M. - O. Rödel (A); Hyperolius jacobseni sp. nov. holotype, ZMB 77280, Gatiko, Central African Republic, photo N. Jacobsen (B); Hyperolius inyangae sp. nov. male holotype, ZMB 77276, Rhodes Dam, Nyanga National Park, Zimbabwe, photo A. Channing (C); female paratype H. inyangae, ZMB 77277, same details (D); Hyperolius nasicus, Nyanga Flats, Zimbabwe, photo A. Channing (E); H. lamottei, night pattern, Mt Nimba, Guinea, photo M. - O. Rödel (F); Hyperolius lupiroensis sp. nov., holotype ZMB 77300, Lupiro, Tanzania, photo A. Channing (G).