Conraua kamancamarai, Neira-Salamea & Doumbia & Hillers & Sandberger-Loua & Kouamé & Brede & Schäfer & Blackburn & Barej & Rödel, 2022

Neira-Salamea, Karla, Doumbia, Joseph, Hillers, Annika, Sandberger-Loua, Laura, Kouame, N'Goran G., Brede, Christian, Schaefer, Marvin, Blackburn, David C., Barej, Michael F. & Roedel, Mark-Oliver, 2022, A new slippery frog (Amphibia, Conrauidae, Conraua Nieden, 1908) from the Fouta Djallon Highlands, west-central Guinea, Zoosystematics and Evolution 98 (1), pp. 23-42 : 23

Conraua kamancamarai sp. nov.

Figs 2 , 3 , 4 , 5 , 6

Holotype.

ZMB 78432 (field and tissue #: GN11-140; GenBank # for 16S: MT669400) adult female, Guinea, Fouta Djallon Region, Konkouré Fetto, 10°20'28.21"N, 12°10'16.82"W, 650 m a.s.l., 20 June 2011, collected by Laura Sandberger-Loua & Joseph Doumbia.

Paratypes.

ZMB 78429 (field and tissue #: GN11-130; GenBank # for 16S: MT669399) adult male; ZMB 78430, ZMB 78433 (field and tissue #: GN11-133, GN11-136; GenBank # for 16S: KF693389) subadults, all other data as holotype.

Additional referred material.

For the description of the new species, we restrict the type series to the population from Konkouré Fetto. We do so because there may be additional undescribed diversity within the group identified as " C. alleni 1b" by Blackburn et al. (2020). The vouchers from Hoere Binti , Pita and Chute de Ditinn , Dalaba (all from Fouta Djallon, Guinea) are, therefore, listed as additional referred material (see Table 2 ) .

Hörè Binti, Pita. ZMB 90301, ZMB 90304 (field and tissue #: CB2010-055, CB2010-061), adult females ; ZMB 90302 (field and tissue #: CB2010-056), adult male ; ZMB 90177 (field and tissue #: CB2010-057; GenBank # for 16S: MT669401 ), subadult ; ZMB 90303 (field and tissue #: CB2010-059), subadult, 10°51'04.8"N, 12°31'14.1"W, 657 m a.s.l.; 22 July 2010, collected by Christian Brede & Joseph Doumbia.

Chute de Ditinn , Dalaba. ZMB 90305, ZMB 90307, ZMB 90309 (field and tissue #: CB2010 082, CB2010 089, CB2010 091), adult males; ZMB 90306, ZMB 90308 (field and tissue #: CB2010 088, CB2010 090), adult females, 10°49'13.1"N, 12°11'30.7"W, 760 m a.s.l.; 24 July 2010, collected by Christian Brede & Joseph Doumbia.

Diagnosis.

The new species resembles other members of the genus Conraua Nieden, 1908. Conraua kamancamarai sp. nov. is an aquatic frog with the following traits: smooth dorsal skin, covered with scattered small, rounded warts on back and longitudinal ridges on dorsal part of hind legs; venter skin smooth; three odontoid projections on lower jaw, one at symphysis and one to each side on dentary; vocal sacs absent; fully webbed feet, i.e. to end of last phalanx of toe. Conraua kamancamarai sp. nov. is closely related to a clade including C. alleni sensu stricto, C. derooi and C. sagyimase (see Blackburn et al. 2020). Genetic distances between the new species and all other Conraua species were higher than 6% in the examined part of the 16S gene.

Conraua kamancamarai sp. nov. can be distinguished from C. goliath by a rounded snout (pointed in C. goliath ), the absence of short dorsal skin ridges, a white venter with dark brown botches (yellow venter in C. goliath ), the presence of a lateral line system, an indistinct tympanum, a wide tarsal fold and by having more than one subarticular tubercle on fingers (one in C. goliath ). Conraua kamancamarai sp. nov. differs from C. crassipes by a white venter with dark brown blotches (uniform white or cream in C. crassipes ), an indistinct tympanum, the presence of a lateral line system, by a conspicuous outer metatarsal tubercle (less conspicuous in C. crassipes ) and by lacking a dermal fold near the elbow. Conraua kamancamarai sp. nov. differs from C. beccarii by the absence of a transverse fold behind the eyes and across the interorbital region, by lacking a swollen post-occipital and suprascapular region in adult males, by a white-coloured venter with dark brown blotches (no spots in C. beccarii ) and by having a head that is as wide as long (wider than long in C. beccarii ). Conraua kamancamarai sp. nov. differs from C. robusta by having a head that is as wide as long (wider than long in C. robusta ), by having a U-shaped notched tongue-tip (tip of tongue rounded in C. robusta ), by a white venter with dark brown blotches (uniformly white or with dark mottling in C. robusta ) and the presence of a lateral line system. Conraua kamancamarai sp. nov. differs from C. alleni sensu stricto by having an undivided palmar tubercle, by having a white-coloured venter with dark brown blotches (uniform light or light with dark mottling in C. alleni ), by a larger inner metatarsal tubercle, a wider tarsal fold and by the presence of webbing between fingers I and II. Conraua kamancamarai sp. nov. differs from C. derooi by having a more slender body and limbs, a slightly curved supratympanic fold (distinctly curved in C. derooi ), two subarticular tubercles on finger III (one in C. derooi ), by lacking a swollen postoccipital and suprascapular region in adult males, by the absence of a divided palmar tubercle, by a white venter with dark brown blotches (uniform whitish or with dark mottling in C. derooi ) and by the presence of webbing between fingers I and II. Conraua kamancamarai sp. nov. differs from C. sagyimase by having narrower fingertips, a wider tarsal fold, by the absence of a divided palmar tubercle, by a white venter with dark brown blotches (uniform pale or with dark mottling in C. sagyimase ) and by the presence of webbing between fingers I and II.

Description of the holotype

(Figs 2 - 5 ; measurements in mm). Adult female; slightly dorsoventrally flattened, short and rounded body; snout rounded in dorsal and lateral view, with upper lip slightly projecting forward; SVL 71.7; head width 23.7, approximately equal to head length 23.5; head length 33% of SVL; snout length 7.0, 30% of head length; eye-nostril distance 4.25; eye-snout distance 8.1; internarial distance 4.0, slightly larger than interorbital distance 5.2; nostrils protuberant, directed dorsolaterally, visible in lateral and dorsal view; large eyes, projecting laterally beyond margins of head in dorsal view; eyes projecting slightly above dorsal margin of head in lateral view; eye diameter 6.5, horizontal diameter of tympanum 4.3; upper eyelid width 3.8, 73% of interorbital distance; eye-tympanum distance 3.9; tympanum indistinct; canthus rostralis distinct and rounded; loreal region concave; slightly curved supratympanic fold extending from posterior edge of eye to shoulder, joining the lateral fold; upper lip slightly protruding; premaxillary and maxillary teeth slender and pointed, three odontoid projections on lower jaw, one on at symphysis and one to each side on dentary; vomerine teeth pointed; about half of anterior tongue attached to floor of mouth, tongue-tip with U-shaped notch.

Forelimbs robust; forearm length 12.4, 74% of hand length 16.8; thenar and palmar tubercle oval and protruding, palmar tubercle larger than thenar tubercle; shape of fingers conical, wider at bases and narrower towards tips; finger tips rounded, non-expanded; one subarticular tubercle on fingers I and II; two subarticular tubercles on fingers III and IV; subarticular tubercles absent on base of fingers; relative length of fingers: III > IV > II ≈ I, length of finger III 9.8; fingers I and II webbed to first subarticular tubercle.

Hind limbs moderately robust; crus length 33.3, 46% of the SVL; foot including longest toe 44.8, 62% of SVL; elongated, prominent oval inner metatarsal tubercle, more than twice as long (4.4) as wide (1.7); outer metatarsal tubercle absent; supernumerary plantar tubercles absent; subarticular basal tubercles absent; one subarticular tubercle on toes I and II; two subarticular tubercles on toes III and V, three subarticular tubercles on toe IV; toe tips rounded, forming small discs, as broad as subarticular tubercles; relative lengths of toes: VI > III > V > II > I; length of toe IV 29.3; webbing complete, i.e. to end of last phalanx of toe; dermal fringing on outer surfaces of toes I and V, forming lateral skin folds; wide tarsal fold.

Skin texture on dorsal parts of head, body, flanks and limbs smooth with scattered, small, rounded warts; upper eyelid skin with many warts; inner surface of upper arm smooth; dorsal surface of crus with 12 rows of longitudinal ridges; ventral skin smooth, throat with longitudinal folds; a post-gular (thoracic) fold extending to level of forelimbs insertion; lateral line system with jugular line, upper lateral line, lower lateral line, median lateral line, caudal lateral line, infra-orbital line, supra-orbital line, mandibular lateral line and anterior lower lateral line (see Shelton 1970).

Colouration in preservative

(after 10 years in 75% ethanol; Figs 2 - 4 ). Dorsum brown with scattered small cream warts, warts more abundant on posterior surface; light interorbital stripe; upper eyelids brown with abundant lighter spots; lips brown or brown with lighter mottling; supratympanic fold brown; lateral fold light; upper arm fold light; dorsal surface of flanks brown; ventral surface of flanks white or light grey with brown spots; dorsal surface of legs brown with dark scattered spots; dorsal surface of toes I, II, III and IV with brown mottling; dorsal surface of toe V brown; dorsal surface of arms brown with scattered light brown warts; dorsal surface of fingers I and II light brown with dark mottling, fingers III and IV brown; ventral surface of throat and belly whitish with dark brown blotches; ventral surface of crus and feet light brown with dark mottling; ventral surface of hands brown.

Colouration in life

(Fig. 5 ). Dorsum dark brown with scattered lighter dots and dark spots; lips same colour as dorsum, paler on lateral surfaces; flanks dark; iris gold; ventral surfaces white with dark brown spots; ventral surface of hands dark, tubercles lighter; ventral surfaces of legs with scattered reddish dots; lateral fold light brown.

Variation

(Figs 6 - 7 ; Tables 2 and 3 ). Overall, the paratypes are similar to the holotype in external appearance and colouration. Dorsal colouration ranges from uniform dark brown ( ZMB 78432) to predominantly brown with dark mottling ( ZMB 78430, ZMB 78431) or predominantly brown with dark spots. In the male paratype ( ZMB 78429), the jugular lateral line is more conspicuous than in the holotype and the upper lip is light brown. Ventral colour pattern of all specimens similar: whitish with distinct brown blotches, however, these blotches are lighter in the subadult paratypes ( ZMB 78430, ZMB 78431).

Referred specimens from Hörè Binti: Dorsal colouration varies from similar to the type series ( ZMB 90177, ZMB 90303) to darker ( ZMB 90301, ZMB 90302, ZMB 90304) or a dark dorsum with light brown spots ( ZMB 90302). Ventral colouration of some individuals deviates from that of the type series by a greyish belly with dark mottling and a dark throat with lighter spots ( ZMB 90304, ZMB 90301). Ventral colouration of ZMB 90302 is difficult to define due to its preservation condition. Ventral colouration of juveniles is showing fewer dark spots than in adults ( ZMB 90177, ZMB 90303). Lateral line system in ZMB 90304 is more conspicuous than in the type series.

Referred specimens from Chute de Ditinn: Dorsal colouration of all individuals darker than that of type series, some individuals with light brown spots ( ZMB 90307, ZMB 90308) that are absent in the type series. Some individuals present a different colouration pattern than type series on the throat with a dark base colour and lighter spots ( ZMB 90306, ZMB 90307, ZMB 90308). Belly of ZMB 90305 greyish with dark mottling, different to the colour pattern of the type series, probably due to preservation. The lateral line system in all individuals is more conspicuous than in the type series. A posterior lower lateral line (see Shelton 1970) is present in ZMB 90307 and ZMB 90309. This part of the lateral line system was not detected in the type series.

For variation in life colouration of Conraua specimens from various localities in the Fouta Djallon Region, see Figure 7 .

Distribution

(Fig. 8 ). So far, the known range of Conraua kamancamarai sp. nov. is restricted to the type locality at Konkouré Fetto and to two other sites, Hörè Binti and Chute de Ditinn. Although the species probably occurs in a few more rivers that have not yet been surveyed, the entire range almost certainly will not extend beyond the Fouta Djallon, where it is very likely patchily distributed.

Biology and habitat

(Figs 9 and 10 ). The new species occupies fast-flowing rocky streams with waterfalls within riverine forest in mountainous areas in the Fouta Djallon, Guinea (Figs 9 and 10 ). Like other frogs of the genus, they are predominately nocturnal and aquatic. Despite their occurrence in fast flowing streams, adults show a preference for calmer river sections, where turbulent water is absent. Usually, frogs are encountered at least partly submerged in shallow water, facing the riverbanks. When outside of the water, they remain within jumping distance to water. Disturbed frogs seek shelter on the ground of pools, sometimes trying to burrow deeper into them and cover themselves with gravel or substrate (Fig. 11 ). This behaviour is similar to what Knoepffler (1985) described for Conraua crassipes . They call (whistle) with an open mouth, sitting in shallow water (Fig. 7 ; compare Amiet 1990). Mating has never been observed by the authors; however, single observations of clutches and jelly remnants of spawn indicate that oviposition sites are small puddles or depressions on the riverbanks near the spray water zone of cascades and waterfalls. Conraua tadpoles usually were observed in silted calm ponds where up to 50 tadpoles of about the same size have been encountered. If this and other species of the genus show breeding behaviour comparable to Conraua goliath (compare Schäfer et al. 2019), remains to be researched.

The surroundings of the forest fragments where the species occurs are generally degraded by anthropogenic disturbance, particularly peanut and rice crops and cattle grazing. The type locality (Fig. 10 ) is located between Konkouré and the largest city within the Fouta Djallon, Mamou, within a relatively short distance to the connection road and was surveyed on 20 June 2011. Along the national route one (N1), one of the largest roads connecting the East with the West of Guinea, houses are numerous, but already within a relatively short distance to the road, human presence may be considerably scarcer. Slopes are either covered by an open, short, dry forest with signs of cattle grazing and used for charcoal production (Fig. 10 ) or comparatively large fields for peanuts or rice crops. Only steep slopes surrounding rivers had sometimes larger trees and denser vegetation with higher humidity levels than the surroundings. The type locality is at a river within denser forest, with large boulders and some cascades, allowing for a diverse river site with fast and slow flowing parts and comparatively clear water (Fig. 10 ). These forests are not protected and were in the past burned by the population as protest against government decisions in Conakry.

The classified forest (partly protected areas allowing forestry) of Hörè Binti is located within a mountainous area containing several freshwater sources. It was surveyed from 22-23 July 2010. Many fast-flowing streams with cascades have its source on the mountain. The habitat degradation due to anthropogenic alterations was dramatic and only very small forest fragments remained. The anthropogenic pressure consisted of cultivations/fields (mainly peanut and rice) and grazing cattle. Only streams were surrounded by some remaining larger trees. The Ditinn / Dalaba site was within a small fragment of gallery forest with a stream, next to the waterfall of Ditinn. It was surveyed from 24-25 July 2010. Although there is a small village next to the forest, only minor anthropogenic alterations were detectable.

Threat status.

Conraua kamancamarai sp. nov. should be considered Data Deficient (DD) because more information is required to make an adequate assessment of the species’ extinction risk. However, if the species range is indeed restricted to the sites of Konkouré Fetto, Hörè Binti and Chute de Ditinn, the species should be categorised as Endangered (EN) following the IUCN (2012) criteria B2bi (continuing decline, observed, inferred or projected in extent of occurrence) and B2biii (continuing decline, observed, inferred or projected, in area, extent and/or quality of habitat).

Etymology.

This species is dedicated to Kaman Camara (Fig. 12 ), our long-term field assistant and friend, who started working with MOR in 2002 on a survey to the Simandou Range that was organised by Conservation International ( Rödel and Bangoura 2004). From 2007 until his recent death, Kaman was a member of our Guinean team, investigating the amphibians of the Nimba Mountains and other Guinean areas. Kaman had outstanding skills in detecting and catching frogs, and, more importantly, an unswerving positive attitude. A day could be completely exhausting and frustrating, but with a simple joke from Kaman all was good again! Kaman was born and lived in a remote village at the western foothills of the Simandou Range. He never received any formal education. Still, he repeatedly rejected other better paying job offers from mining companies, preferring instead to work with his frog team whenever it was possible. Kaman died in June 2020 after a short severe disease. These frogs shall be a permanent memory to an outstanding person! We suggest 'Kaman Camara’s Slippery Frog’ as the English common name, 'la grenouille glissante de Kaman Camara’ in French and in the local language Poular: ‘Tôti bhowroundi de Kaman Camara’.

Figures

Figure 2. Ventral view of hands of four Conraua species showing palmar tubercles differences. Whereas three species possess a divided (outer and middle) palmar and a thenar tubercle, Conraua kamancamarai sp. nov. has an undivided palmar and a thenar tubercle. a. Conraua kamancamarai sp. nov. holotype (ZMB 78432); b. C. derooi (MNHN-RA 1993 4087); c. C. sagyimase (UWBM Herp 05841, paratype); d. C. alleni (ZMB 90390); Scale bars: 5 mm.

Figure 3. Conraua kamancamarai sp. nov., female holotype (ZMB 78432) in lateral, dorsal and ventral view. Scale bar: 20 mm.

Figure 4. Conraua kamancamarai sp. nov., female holotype (ZMB 78432) lateral view of head and ventral view of left foot. Scale bar: 10 mm.

Figure 5. Conraua kamancamarai sp. nov., female holotype (ZMB 78432) in life.

Figure 6. Dorsal and ventral views of paratypes of Conraua kamancamarai sp. nov., male (ZMB 78429), subadults (ZMB 78430, ZMB 78431). Scale bars: 20 mm.

Figure 7. Colouration of life Conraua kamancamarai sp. nov. from the Fouta Djallon and surrounding region, Guinea, illustrating variation in colour pattern and skin texture. a. From Dubreka, River Bindinbandan (10 ° 22 ' 21.9 " N, 13 ° 9 ' 16.8 " W, 199 m a. s. l.); b. From Dalaba, Chute de Ditinn; c. From Hoere Binti; d. From Dubreka, River Bindinbandan (10 ° 22 ' 21.9 " N, 13 ° 9 ' 16.8 " W, 199 m a. s. l.); e. From Dalaba, Chute de Ditinn; f. From Telimele, locality Kourakoto, river Didounpourigue (10 ° 55 ' 30.4 " N, 13 ° 47 ' 39.4 " W, 238 m a. s. l.); frogs in lower row in typical calling position, sitting in shallow water; specimens either not collected or not assignable to a voucher specimen, whereas the frogs from Hoere Binti and Chute de Ditinn can be assigned to Conraua kamancamarai sp. nov. without doubt; the other frogs may represent an undescribed Conraua.

Figure 8. Map of known localities of Conraua kamancamarai sp. nov. in the Fouta Djallon Highlands, Guinea. Inset (upper right) shows a map of West Africa indicating in red, the area of occurrence of the new species in the Fouta Djallon and in blue, the assumed type locality of C. alleni. Known localities of Conraua kamancamarai sp. nov. are shown in red (Konkoure Fetto, type locality: star; Hoere Binti: circle; Chute de Ditinn: square), the population from Soyah, potentially representing another undescribed Conraua, is given in yellow. Altitudinal range is indicated with light shading from lowlands (112 m a. s. l.) to dark shading highlands (1089 m a. s. l.). Sources: OpenStreetMap (2020), U. S. Geological Survey (2020).

Figure 9. The Fouta Djallon, Guinea and habitats of Conraua kamancamarai sp. nov. Hoere Binti landscape (upper photo) and typical river habitats.

Figure 10. The type locality of Conraua kamancamarai sp. nov. near Konkoure Fetto, Fouta Djallon, Guinea (10 ° 20 ' 28.21 " N, 12 ° 10 ' 16.82 " W, 650 m a. s. l.). The frogs live in clear, fast flowing streams, with riverine forest. The surroundings are heavily degraded by agriculture, cattle grazing and charcoal production (inset figure).

Figure 11. Conraua alleni hiding on river bottom, the new species shows an identical behaviour when trying to escape.

Figure 12. Kaman Camara in June 2007 on Mount Nimba, Guinea. Inset figure taken on a Rapid Assessment to south-eastern Guinea, organised by Conservation International and Kaman's first experience with frog work, from left to right: Mark-Oliver Roedel, Mohamed Alhassane Bangoura and Kaman Camara.