Hyperolius adspersus Peters, 1877

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 : 314-317

Hyperolius adspersus Peters, 1877

Sprinkled Long Reed Frog ( Fig. 4 )

Synonymy. Hyperolius granulatus (Boulenger, 1901) .

Genetic material. USNM 578140, 578144, 578166 (Plain of Vera, 15 km south east of Gamba, Gabon); USNM 578157 (Uemba Road, 2 km south of Gamba, Gabon); USNM 578142 (Setecama Road, 3 km west of Gamba, Gabon); USNM 578165 (National Forestry School, Gabon) ( Fig. 1 ). Specimens examined as above, including the type (ZMB 917).

Diagnosis. The advertisement call consists of a brief note, duration 0.04 s, and indistinguishable pulses ( Fig. 5 ). It can be distinguished from the call consisting of a brief note comprising a few initial pulses, followed by a number of pulses at a much slower pulse rate, such as H. benguellensis , H. friedemanni sp. nov., H. howelli sp. nov., H. igbettensis , H. inyangae sp. nov., H. rwandae sp. nov., H. viridis and H. poweri . It differs from the longer calls consisting of a number of pulses at a more or less constant rate, such as H. acuticeps , H. jacobseni sp. nov., H. nasutus , H. nasicus and H. dartevellei . See Table 3 for a summary of call parameters. The snout is truncated to bluntly rounded, which differs from the sharp, shark-like profile of H. benguellensis and H. inyangae sp. nov., and the sharply rounded snout profile of H. acuticeps , H. friedemanni sp. nov., H. lupiroensis sp. nov., H. nasutus and H. rwandae sp. nov. The fifth toe has about half a phalanx free of web. This distinguishes it from those species that have one or more phalanges of the fifth toe free, H. benguellensis , H. howelli , H. inyangae , H. lamottei and H. nasicus ; and those with the fifth toe fully webbed, H. friedemanni , H. jacobseni , H. lupiroensis and H. rwandae .It has one phalanx free of webbing on the fourth toe, which distinguishes it from H. dartevellei , which has less than a phalanx free; nasutus which is webbed to the disc at least on one side; and H. poweri and H. viridis which have more than one phalanx free. It has no more than one phalanx free on the second toe, at least on one side, which distinguishes it from H. igbettensis which has more than one phalanx free of the second toe at least on one side

Description of a specimen from Gamba, Gabon. An adult male USNM 578142 (measurements presented in Appendix 2) measuring 19.5 mm SUL; body long and slender, widest just behind orbital region, tapering to groin; head relatively small (HL/SUL 0.27, HW/SUL 0.33), wider than long (HL/HW 0.82); snout long (SL/HL 0.51, truncated in dorsal view ( Fig. 6 ), just protruding just beyond lower jaw, wider than long (SL/EE 0.64); canthus rostralis rounded; loreal large and oval in shape; nostril directed laterally, eliptical slit, situated just behind the tip of the snout (EN/NS 1.60), separated from each other by distance greater than distance between eye and nostril (NN/EN 1.19); eyes large (ED 2.0), directed anterolaterally, protruding outwards and forward, pupil is horizontal to circular, visible from below, eye diameter shorter than snout (ED/SL 0.74); interorbital distance much wider than upper eyelid (IO/EW 1.46), and equal to internarial distance (IO/NN 1.0); tympanum not visible externally; upper jaw with dentition; teeth on premaxilla larger than those on maxilla; choanae large, oval, vomer processes and teeth absent; tongue long and broad, mostly free except for first quarter, bifurcated distally for about one-fourth of length; median lingual process absent; vocal sac single, median, subgular; large granular gular flap covering thin vocal sac (4.3 wide).

Dorsal surfaces of head, trunk and limbs generally appearing smooth but with many densely and more or less evenly scattered tiny, melanophores; ventral surface of limbs and gular smooth, chin and abdomen slightly more areolate; supratympanic fold absent.

Fore limbs slender; hand moderately large (HND/SUL 0.28); tips of fingers enlarged into broad oval disks, thin circummarginal groove; relative length of fingers: I<II<IV<III; subarticular tubercles rounded, well developed, with one per phalange; webbing formula of the hand I 2.5–2.5 II 2 –2.25 III 2.25– 2 IV; thenar tubercle indistinct; palmar tubercles absent.

Hind limbs slender, moderately long; tibiofibula moderately long (TFL/SUL 0.54), longer than thigh (TFL/ THL 1.08); 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 0.85); relative length of toes: I<II<III<V<IV; discs of toes similar in size to 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– 2 II 1– 2 III 1– 2 IV 2– 1 V; inner metatarsal flat; outer metatarsal tubercle absent.

Colouration in life. No information, but see the photo ( Fig. 4 ) of an unvouchered individual from the Bateka Nature Reserve, Gabon. Colouration in preservative. All colours have faded to a beige yellow with evenly spaced black dorsal melanophores.

Eggs and tadpoles. Unknown.

Habitat. Specimens were collected in grassland.

Distribution. Southern Cameroon, east and south through Gabon to the lower Congo Basin.

Remarks. The synonomy of H. granulatus (the holotype RMCA-152 was examined) is supported by the absence of dorso-lateral stripes and a short rounded snout. The species is presently only confirmed from northern Angola, the Cabinda enclave, and Gabon. There is little doubt that existing records refer to this species, and we suggest that its conservation status of Least Concern remains unchanged.

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 4. Hyperolius acuticeps Chongoni, Malawi, photo V. Mercurio (A); H. adspersus Bateka Nature Reserve, Gabon, photo G. Jongsma (B); H. benguellensis, Humpata, Angola, photo A. Channing (C); H. friedemanni sp. nov., Karonga, Malawi, photo V. Mercurio (D); H. howelli sp. nov. holotype, SAIAB 118979, Arusha, Tanzania, photo A. Channing (E); H. howelli sp. nov. female paratype, SAIAB 118980 - 1, Arusha, Tanzania, photo A. Channing (F).

FIGURE 5. Advertisement calls of H. acuticeps Kaningina (left), H. adspersus Bateka Nature Reserve (center) and H. dartevellei Carumbo (right).

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.