Hyperolius igbettensis Schiøtz, 1963

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 : 324-326

Hyperolius igbettensis Schiøtz, 1963

Igbetti Long Reed Frog ( Fig. 12 )

Genetic material. Two samples without vouchers, and ZMB 76542–43 (Lamto, Ivory Coast); ZMB 77415 (Kérouane, Guinea); ZMB 77416 (Konsankoro, Guinea); ZMB 77410 (Dantilla, Guinea) ( Fig. 1 ).

Diagnosis. The advertisement call ( Fig. 10 ) consists of an initial brief note with 12 pulses, followed by five slower pulses, with a duration of 0.12 s. It can be distinguished from species producing only a single note, and those producing only a buzz: H. acuticeps , H. adspersus , H. jacobseni sp. nov., H. lupiroensis sp. nov. and H. nasutus . It differs from species producing a call over 0.2 s; H. benguellensis , H. inyangae sp. nov. and H. viridis , and from those where the initial note consists of less than 10 pulses: H. friedemanni , H. howelli , and H. poweri . The snout is bluntly round in profile, which distinguishes it from species with truncated, shark-like, or sharply rounded profiles; H. acuticeps , H. adspersus , H. benguellensis , H. dartevellei , H. friedemanni , H. howelli , H. inyangae sp. nov., H. lupiroensis sp. nov., H. nasutus and H. rwandae sp. nov. The foot is webbed with one or more phalanges free of web on the first four toes, and half free on the fifth toe. This distinguishes it from species where at least one toe is webbed to the disc, at least on one side: H. adspersus , H. benguellensis , H. friedemanni , H. jacobseni sp. nov., H. lupiroensis sp. nov., H. nasutus and H. rwandae sp. nov. It differs from species that have at least one phalanx free on the fifth toe; H. acuticeps , H. dartevellei , H. howelli , H. inyangae and H. nasutus . Finally, it differs from the two species that have one or less phalanges of the second toe free of web: H. poweri and H. viridis .

Description of a Dantilla specimen. This is based on ZMB 77410, an adult female. The ranges are given from three specimens (ZMB 77410–412; 1 female, 2 males), with single measurements from the sequenced specimen. Elongate, fragile frogs; Body long and slender (SUL 21.1), widest at temporal region (HW 5.8–7.0; 7.0), slightly tapering to groin; head comparatively small (HL/SUL 0.33, HW/SUL 0.26), not wider than trunk, longer than wide (HL/HW 1.27); snout long (SL/HL 0.43), subelliptical in dorsal view and protruding in lateral view ( Fig. 6 ), projecting beyond lower jaw, wider than long (SL/EE 0.73); canthus rostralis indistinct, roundish, straight-lined from eye to just beyond nostril, slightly convex near tip of snout; loreal region almost vertical, slightly concave; nostril round, directed dorsolaterally; situated much closer to tip of snout than to eye (EN/NS 1.91), separated from each other by distance slightly less than distance between eye and nostril (NN/EN 0.90); eyes directed anterolaterally, protruding, relatively small (ED/HL 0.29); eye diameter shorter than snout (ED/SL 0.67); interorbital distance narrower than upper eyelid (IO/EW 0.8), and greater than internarial distance (IO/NN 1.11); tympanum barely visible, very small with tympanum-eye distance equal to half diameter of eye; 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 5.0, and wide (3.6 at widest point), free for about three-fourths of length, bifurcated distally for about one-fourth of length; median lingual process absent; vocal sac single of males, median, subgular, mostly unpigmented and translucent when fully inflated; gular gland large covering 2/3 to almost entire throat, dilatable skin visible posterior to gland; width of male gular flap 3.6–4.8; gular flap consisting of two medially arranged, heart shaped and triangular areas of thickened skin, immediately adjacent to each other; anterior, heart shaped, light yellow, larger, more granular, and thicker than posterior, triangular white-coloured part; in resting position only anterior part visible from ventral;

Dorsal surfaces of head, trunk and limbs generally smooth; ventral surface of limbs and gular smooth, lower belly slightly more areolate; a few warts in angle of mouth; supratympanic fold absent.

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: 1<2<4<3; 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; finger webbing reaches the proximal subarticular tubercle between fingers 2 and 3, and between 3 and 4, with only traces of webbing on the other fingers; thenar tubercle indistinct, low; palmar tubercles absent; metacarpals without supernumerary tubercles; nuptial pads or asperities absent.

Hind limbs slender, moderately long (LEG/SUL 1.58); tibio-tarsal articulation almost reaching to level of tip of snout when legs are adpressed to body; tibiofibula moderately long (TFL/SUL 0.58), longer than thigh (TFL/ THL 1.13; TFL 10.7–11.0); 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 0.86; FOT 10.5–15.3); 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+–1.25 II 0.25– 2 III 2– 1 IV 1–0.3 V; no visible internal or external metatarsal tubercles.

Colouration in life. The basic colour of live frogs ranges from a light bluish green, to grass green or almost green-brown; shanks, lower and upper arms are almost transparent blue-green; flanks, back and thighs darker green with many small dark spots, sometimes arranged along vertebral line into a broken line; eyelids usually lighter than rest of head and dorsum, yellowish to reddish brown; sometimes head darker (reddish brown) than rest of dorsal surfaces; in some animals, mostly males, light white to yellow dorsolateral stripe, rarely bordered by two dark lines; dark canthal stripe, reddish iris bordered by narrow blue line; gular gland of males yellowish or like rest of vocal sac skin light green-blue; ventral surfaces light, belly whitish, often almost transparent; toe and finger tips yellow to orange; females are usually more “transparent” than males, with eggs visible through the body wall. Colouration in preservative. Very pale beige in preservation with small dark spots scattered over back and extremities, with or without a distinct white dorsolateral band.

Eggs and tadpoles. Unknown.

Remarks. The biology of this species was discussed by Rödel et al. (2006). The species is now known from Guinea to Cameroon, and perhaps occurs further east (Amiet 2006a). We suggest that the IUCN status of Least Concern be maintained.

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 10. Advertisement calls of H. howelli Arusha (left), H. igbettensis Comoé National Park, Ivory Coast (center) and H. inyangae Rhodes Dam (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).