A new species of grass frog of lhe genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schillukorum and Ptychadena mossambica, the new species differs In advertisement call, and external characters. An examination of a series of published sonagrams indicates that Ptychadena floweri must be regarded as a junior synonym of P. schillukorum

Channing, A

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142 S.-A&. Tydslcr. Dierk. 1993,28(3) A new grass frog from Namibia A. Channing Biochemistry Department. University of the Western Cape, Private Bag X17, Bellville, 7535 RepubflC of SoU1h Africa Received 21 December 1992; accepud 24 Febrll.tJF'j 1993 A new species of grass frog of the genus Ptychadena is described from northern Namibia. Although superficially similar to Ptychadena schilJukorum and Ptychadsna mossambica. the new species differs In advenisemen1 call, and erlernal charaders. An examination of a series of published sonagrams indicates that Ptychadsns {/owen must be regarded as a junior synonym of P. schillukorum. 'n Nuwe graspadda-spesies van die genus Ptychad9()a word van noordelike Namibia beskryf. Alhoewel dlt oppervlakkig soortgelyk is aan Ptychadena schlllukorum en Ptychad9n8 mossambica, Is daar duldefike verskine in advertensieroep en ekS1erne kenmerke. 'n Ondersoek van 'n reeks sonagramme toon dat Ptychadsns f/owsri 'n ju nier sinoniem van P. schiHukorum is. Grass frogs of the genus prychadeTlll are widespread in the warm and wet areas of Africa. Although many arc difficult to separate on external morphology. the species are readily separable as each produces loud and characteristic vocaliza-tions (Passmore 1977). Amongst a collection of frogs from the Caprivi strip in Namibia. held in the State Museum, Windhoek and the California Academy of Sciences, were some identified as P. COlli (=P. schilluJcorum) (Channing 1989) and believed to be a new record for the country. However. Poynton & Broadley (1991) noted that the Caprivi frogs were not conspecific with P. schillulwrwn. Superficially they resemble P. mos-sambica and P. schilluJcoTUTn. the latter not known from Namibia. The call of the Namibian frog is quite different from both P. mossambica and P. schil/ukorwn. On the basis of small differences in morphology and a distinct advertise-ment call it is described as a new species. ptychadena mapacha n, sp, Holorype: A male. collected from Mapacha (Mpacha), in the eastern Caprivi. Namibia. 17"38'S / 24°IO'E, February 1986, by A. Channing. The specimen is housed in the State Museum, Windhoek, SMR 26145. Paratypes: Two male paratypcs are housed in the California Academy of Sciences. CAS 160535 and 160547, collected February 1986, by A. Channing. from Katima Mulilo. 17° 32'S /24°15'E. Diagnosis: Externally very similar to PrycJuu1ena schillu-/corum. with shon legs and small dark markings on the dor-sum. Distinguishable. in the small sample examined. by the unbroken ridgc extcnding from the upper lip. below the tympanum. back nearly to the ann insertion (Figure I). In P. schillukorwn the ridge is broken. PtychadeTlll mossambica does not always possess a distinct ridge from the upper lip, and the Oanks arc very granUlar. P. mapacha has a few Oat granules on the posterior nanks. The male advertisement call is quite distiocL Description of h%rype. A male, SVL 29 mm. The snout is sharp, protruding beyond the mouth. The nostrils are oval, rimmed, and situated 2 mm (40%) back from the snout to the anterior corners of the eyes. Each nostril is situated at the anterior end of a depression formed by slight swellings of the upper lip and canthus. The eyes are small, 2 mm in diameter. The distance be[Ween the anterior comers of the eyes is equal to the snout-eye distance. The tympanwn is small (2.4 mm). round. and sube<Jual in diamel.er to the eye. The upper lip ex.tends into an unbroken pale ridge below the tympanum ending just anterior to the top of the arm insenion. The vocal pouch slilS are parallel 10 the upper lip. opening below the ann insertion. The vocal pouch is darlcened anteriorly. as seen partially protruding from the vocal pouch slit. The anns are short. with large subarticular tubercles on the palms and fingers (Figure 2). Vomerine projections occur anteriorly to the internal nostrils. Maxil-lary teeth are visible from below. with teeth on the sides of the maxilla projecting backwards at 4SO to the jaw line. The legs are short, the tibia being 14 mm. and the foot, measured to include the metatarsal tubercle. 11 mm. A pale ridge runs distally along the tarsus from the inner metatarsal tubercle. Toes partially webbed, with 2J1J to 3 phalanges of fourth toe free of web. The longitudinal ridges on the dorsum, charac-teristic of the genus PtycJuu:kM. are indistinct and intenuptc.d. Four ridges can be counted be[Ween the tympanii, and nine across the dorsum at the widest part (Figure 3). The vcntrum is pale, immaculate and smooth. Figure I A male PlychadefI/J mDplIcha n. sp. Snout-vent length 30 mm. Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2010). S. Afr. I. Zoo1. 1993,28(3) Figure 2 The lower surfaces of the hands and feet of Ptychadella mapacha (SMR 26145). Scale line = 5 mm. Figure 3 The dorsal pattern and longitudinal skin ridges of Ptychadella mapacha (SMR 26145). Dorsal patterning consists of small, dark eye-sized markings against a shaded background. The legs are barred with two broad continuous dark bars on the anterior face of the thigh, and four broken bars across the tibia. The posterior face of the thigh is mouled, tending to form a longitudinal pale line. The posterior face of the tibia has a number of small white spots. A thin tibial line is present in CAS 160535. A pale flattened broken ridge runs from the eye to the leg insertion 143 Table 1 Measurements (mm) of the holotype and paratypes of Ptychadena mapacha SMR 26145 CAS 160535 CAS 160547 Snout-vent 29 29 28 Tibia 14 15 14 Foot 11 13 13 Tympanum 2,4 2,5 2,8 Ant. borden of eye 5 4,5 5,1 Snout-nostril 2 1,5 2,5 Snout-eye 5 4,5 5,6 (Figure 1). In other specimens this ridge is unbroken. A pale thin venebral stripe is present in CAS 160535. Measure-ments of holotype and paratypes are listed in Table 1. Colour in life. The dorsum is olive brown with dark brown spots. The ridge along the upper lip back to the arm insertion, and the ridge running backwards from the eye, are cream. Reddish-brown infusions are present behind the tympanum and on the tibia. The upper ann shows an orange-brown tinge. The tympanum has a pale edge. Etymology. The epithet mapacha is derived from the name of the area around the airfield outside Katima Mulilo. Although not part of the local language, Lozi, the word is believed to refer to the recent nature of the seulement. It is a noun in apposition. Advertisement call All recordings were made in the field using a Sony TCD 5M recorder and a directional microphone. Air temperatures were between 23°C and 25°C. Males call from concealed positions under vegetation, while sitting in shallow water. Males were heard calling in groups and singly. The call con-sists of a short whistle, with a duration of 50 ms, produced at a rate of six calls per second. Each note rises in pitch with the emphasized frequency at 1,6 kHz, and harmonics at 2,0 and 3,8 kHz (Figure 4). The analysis was carried out with the program SOUNDEDIT (Farallon). The calls of two other species, P. mossambica and P. schilluJcorum, with which P. mapacha might be confused morphologically, are also illustrated. There is as yet no evidence that P. schilluJcorum and P. mapacha are sympatric. Eggs and tadpoles These are presently unknown. TIle eggs of other species of Ptychadena in the area are deposited in small muddy pools, where they float on the surface. The known tadpoles of this genus are all very similar (power 1927; Guibt & Lamotte 1958; Lamotte & Perret 1961; Laurent 1964; Van Dijk 1966; Stevens 1972) and it is expected that the eggs and tadpoles will resemble other Ptychadena species. Distribution Presently P. mapacha is only known from Katima Mulilo Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2010). 144 S.-Afr. Tydskr. Dierk. 1993.28(3) 1"'· "'J: 5 4 3 kHz 2 1 0 0 1.4 seconds Figure 4 The advertisement calls of PtycluJdena mossambica CAS 160419 Oeft-most). Ptychadena mapacha SMR 26145 (middle three). and Ptychat/ena schillukorum CAS 182008 (right-most eight). The calls of P. mossambica and P. mapacha were recorded at Katima Mulilo in Namibia, and the call of P. schillukorum was recorded at Beira in Mozambique. P. schillukorum is not known to be sympatric with P. mapacha. Table 2 Advertisement call parameters from known sonagrams of Ptychadena schillukorum. including P. floweri. now included in its synonymy Locality and Source Ghana Tanzania Schiou V.d. Elzen Cameroon Malawi Mozambique Amiet SleVens Field record (1964) & Kreulen (1974) (1974) Note dura-tion (ms) Number of noces Low empha-sized fre-20 quency (Hz) SOO High empha-sized fre-quency (kHz) 3,5 Notes/s 17 (1979) 25 7 900 2,6 13 20 6 1000 2,6 17 Call posi-tion Description close to floating floating puddle 'dry 'dry rat- 'machine rattl e' tle or ma-chine gun' gun' 32 8 650 3,3 14 floating 'machine gun' and surrounding areas in Namibia. Other specimens belong-ing to this new species may be found in collections present-ly identified as P. schillukorum (P. colti or P. flowerl). Extensive fieldwork is required. as the distinct advertise-ment call would be the first clue to the presence of this species. The status of Ptychadena floweri The taxonomy of some grass frogs, previously confused as Ptychadena colti, P. schillukorum or P. floweri was reviewed by Perret (1987). He showed that the three names were probably synonymous, with the senior synonym, P. schillukorum, being applied to the form known from Mozambique northwards to Somalia. Perret tentatively retained the name P. flower; for the form reaching west Africa. The published descriptions of calls from Ghana to Malawi are similar (perret 1987). Examination of all the published sonagrams of P. flower; and P. schillukorum (Schit'ltz 1964; Amict 1974; Van den Elzen & Kreulen 1979), plus analysis of P. schillukorum calls recorded in Mozambique. shows that only one species is present as all the call parameters are similar (Table 2). Voucher specimens are available for all recordings. In view of this, the frog from west Africa previously known as Ptychadena floweri should be synonomized with P. schilluJcorum. Unlike most other grass frogs, P. schillukorum calls while floating. Material examined Ptychadenaflower;: CAS 148163, 148167, 148194,148195, 148299, 152863. Ptychadena mossambica: CAS 160419, 160420, 160426. 160431, 160450, 160466. Ptychadena schilluJcorum: CAS 182008 Acknowledgements The Ministry of Wildlife, Conservation and Tourism of Namibia provided collecting permits, and the University of the Western Cape assisted financiaJJy. Mike Grifrm is thanked for his support of this research in Namibia. Specimens were kindly loaned by lIke von Holtz (State Museum, Windhoek) and Jens Vindum and Bob Drewes (CAS), who also measured CAS 160547. References AMIET J.-L. 1974. Voix d'Amphibienscamerounais IV.-Raninae: genres PlycluJdena. HildebraradJiIJ et Dicroglossus. Ann. Fac. Sci. Univ.fed. CamI!rolUl 18: 109-128. CHANNING, A. 1989. New frog records from the Eastern Caprivi Strip, South West Africa/Namibia. Madoqua 16: 1-4. Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2010). S. Afr. J. Zool. 1993,28(3) GUIB& J. & LAMUITE, M. 1958. La reserve naturelle integrale du Mont Nimba. Fasc. IV. XII Batraciens (sauf Arthroleptis, PhryflObalrachuset Hyperolius). Mem. Inst.fra"f. Afr. Mire. 53: 241-273, pIs. I-XI. LAMUITE, M. & PERRET, J.-L. 1961. Contribution ll'etude des batraciens de l'Ouest africain. XI - Les formes larvaires de trois espees de Ptychade"a: Pt. maccarthyensis And., Pt. perreti G. et L. et Pt. mascare"ie"sis D. et B. Bull. Inst. fra"f Afr· Mire 23A: 192-210. LAURENT, R.F. 1964. Reptiles et Amphibiens de l'Angola (froisi~me contribution). Publ. Cult. Compo diam. A"gola 67: 11-165. PASSMORE, N.I. 1977. Mating caBs and other voca1izations of five species of PtychacUfIa (Anura: Ranidae). S. Afr. J. Sci. 73: 212-214. PERRET, J.-L. 1987. A propos de PtychacUfIa schillWcorlUll (Werner, 1907)(Anura, Ranidae). Bull. Soc. Muchlit. Sci. nat. 145 110: 63-70. POWER,J.H. 1927. Notes on the habits and life-histories of South African Anura, with descriptions of the tadpoles. Trans. Roy.Soc.S.Afr. 14: 237-247. POYNTON, J.C. & BROADLEY, D.G. 1991. Amphibia Zambesiaca 5. Zoogeography. A"". Natal MIlS. 32: 221-277. SCHI~, A. 1964. The voices of some west African amphibians. Viti. Medd. Daf\slr.. nat",h. Fore". 127: 35-83. STEVENS, R.A. 1972. A new species of Ptychade"a (Amphibia: Ranidae) from southern Malawi. ArMldia (Rhod.) 5: 1-14. VAN DEN ELZEN, P. & KREULEN. D.A. 1979. Notes on the vocalizations of some amphibians from the Serengeti Nationa1 Park. Tanzania. BOM zool. BeiJr. 30: 385-403. VAN DUK. D.E. 1966. Systematic and field keys to the families. genera and described species of southern African tadpoles. A"". Natal MIlS. 18: 231-286. Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2010). 

A new grass frog from Namibia

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A new grass frog from Namibia

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