Hyperolius jacobseni, 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

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 : 327-329

Hyperolius jacobseni sp. nov. Channing

Jacobsen's Long Reed Frog ( Fig. 12 )

Holotype. ZMB 77280, a male, collected near Gatiko, Central African Republic, 5°4'43" N, 20°40'2" E, by N. Jacobsen, 29 August 2006.

Paratypes. A female, ZMB 77281, with the same details as the holotype; 16 males and one female, ZMB 77282–298, collected at the same locality, and within a few days of the holotype.

Genetic material. ZMB 77280–1 (holotype and paratype) ( Fig. 1 ).

Diagnosis. The advertisement call ( Fig. 11 ) consists of a short buzz with five pulses, with a duration of 0.06 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. dartevellei , H. friedemanni , H. howelli , H. igbettensis , H. inyangae , H. lupiroensis sp. nov., H. poweri , H. rwandae sp. nov. and H. viridis . It can be distinguished from the other species with a buzz call by the number of pulses: 25 pulses in H. acuticeps , and eight pulses in H. nasutus . See Table 3 for a summary of call parameters. The snout is bluntly round in profile, distinguishing it from those with truncated, shark-like or sharply rounded snouts: H. acuticeps , H. benguellensis , H. dartevellei , H. friedemanni , H. howelli , H. inyangae , H. lupiroensis sp. nov., H. nasutus and H. rwandae sp. nov. The toes are webbed with one phalanx of the third and fourth toes free, and the fifth toe webbed to the disc. This pattern distinguishes it from those species that do not have the fifth toe webbed to the disc: H. acuticeps , H. benguellensis , H. dartevellei , H. howelli , H. igbettensis , H. inyangae , H. nasutus , H. poweri , and H. viridis . It differs from H. friedemanni which has all the toes webbed to the disc, and from H. rwandae sp. nov. which has two phalanges of the third toe free. The webbing is similar to that of H. lupiroensis sp. nov.

Standard measurements of the holotype are compared with the other species in Appendix 2.

Description of Holotype. Body long and slender, widest at temporal region, slightly tapering to groin; head comparatively small (HL/SUL 0.34, HW/SUL 0.28), not wider than trunk, longer than wide (HL/HW 1.22); snout long (SL/HL 0.43), bluntly rounded in dorsal view, truncated in profile ( Fig. 6 ), not significantly projecting beyond lower jaw, wider than long (SL/EE 0.74); canthus rostralis distinct, rounded, strongly concave from eye to nostril, slightly convex near tip of snout; loreal region almost vertical, slightly concave; nostril directed laterally; situated much closer to tip of snout than to eye (EN/NS 1.6), separated from each other by distance greater than distance between eye and nostril (NN/EN 1.31); eyes directed anterolaterally, moderately protruding, relatively small (ED/ HL 0.25); eye diameter shorter than snout (ED/SL 0.58); interorbital distance much wider than upper eyelid (IO/ EW 2.9), and greater than internarial distance (IO/NN 1.38); 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 4.7, and narrow (2.8 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, median, subgular; gular flap consisting of two medially arranged, subcircular areas of thickened skin, immediately adjacent to each other; anterior part cream-coloured, larger, more granular, and thicker than posterior white-coloured part; vocal sac aperture on each side of the mouth, slit-like, long.

Dorsal surfaces of head, trunk and limbs smooth but with many densely and more or less evenly scattered tiny, low, spine-like tubercles; 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 –2.5 II 2.5– 3 III 2.5– 2 IV; thenar tubercle indistinct, low; palmar tubercles absent; metacarpals without supernumerary tubercles; nuptial pads or asperities absent.

Hind limbs slender, moderately long (LEG/SUL 1.60); tibio-tarsal articulation reaching to level of tip of snout when legs are adpressed to body; tibiofibula moderately long (TFL/SUL 0.52), longer than thigh (TFL/THL 1.05); 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 0.78); 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 – II 0.25– 1 III 0.25– 1 IV 1–0 V; inner metatarsal tubercle small, oval, prominent; outer circular, low and less distinct.

Colouration in life. The body is an overall yellow-brown, with a green tinge visible through the skin of the sides of the body. The lateral stripes are bright white, edged with brownish pigment spots. Colouration in preservative. Colour in preservative pale yellow, with pigmented snout, a blotch of pigment on top of the eye, and minute black melanophores on the back, more dense anteriorly, with larger brown spots irregularly scattered. White lateral lines run from the top of the eye to the groin, bordered by dark lines of spots and melanophores. The belly is white.

Paratype variation. The paratypes are similar in size and proportions to the holotype, with the large female ZMB 77281 having SUL 19.5 and with HW 6.2, with the largest female having SUL 21.5. The male paratypes have a conspicuous muscle (m. ileolumbaris) running from behind the tympanum to the groin, visible under the skin. The inner metatarsal tubercle is flattened, while the outer metatarsal tubercle is absent. The discs on the toes are slightly wider than the width of the toes.

Eggs and tadpoles. A female paratype ZMB 77281 contains enlarged ovarian eggs with a diameter of ca. 1.1. Eggs are darkly pigmented on the animal pole and white on the vegetative pole. Tadpoles are unknown.

Habitat. The types were found on emergent grass and other plants around temporary pools.

Etymology. This species is named for the collector, the South African herpetologist Niels Jacobsen.

Remarks. The species is only known from southern Central African Republic, although it is probably widespread. It should be regarded as Data Deficient in terms of the IUCN criteria.

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).