A new giant species of Arthroleptis (Amphibia: Anura: Arthroleptidae) from the Krokosua Hills Forest Reserve, south-western Ghana Author Ernst, Raffael Author Agyei, Alex C. Author Rödel, Mark-Oliver text Zootaxa 2008 1697 58 68 journal article 10.5281/zenodo.180740 727b5424-a42a-493c-ae17-fbad8934319b 1175-5326 180740 Arthroleptis krokosua sp. nov. Figs 1–3 Holotype . An adult male ( SMNS 12555; GB: EU350211 ; field number KHA0103) collected by A.C. Agyei and R. Ernst on 8 November 2003 on a steep hill, SE of the base camp (at village of Mmem), in the Krokosua Hills Forest Reserve, south western Ghana ( 6°35.970’ N , 2°50.705’ W ; GPS geodetic datum: WGS84; altitude ca. 300 m asl). The habitat consisted of dry forest with a thick leaf litter on a granitic outcrop. Etymology. The species is named after the type locality Krokosua Hills. The name was chosen to highlight the extraordinary importance of the location in the context of the conservation of Globally Significant Biodiversity Areas (GSBA) in the Western Region, Ghana . The specific epithet is treated as a noun in apposition. Adult definition and diagnosis . A large Arthroleptis , snout-vent length (SVL) 43.3 mm ; sturdy and compact, broad head; Astylosternus -like habitus ( Fig. 1 a–c, Fig. 3 ); larger and more compact body shape than all other known West African Arthroleptis species; well developed maxillary teeth; inner metatarsal tubercles elongated, reaching 80.9% of the length of first toe; tips of toes are slightly expanded into discs and tips of fingers are slightly swollen ( Fig. 2 ). FIGURE 1. Dorsal (a), ventral (b), and latero-ventral (c) view of the Arthroleptis krokosua sp. nov. holotype (SMNS 12555). Photographs R. Ernst FIGURE 2. Right hand and plantar surface of right foot of the Arthroleptis krokosua sp. nov. holotype (SMNS 12555). Photographs R. Ernst. Description of the holotype . A male (SMNS 12555) with SVL of 43.3 mm ; sturdy compact body shape ( Fig. 1 a, c); head width 19.7 mm ; interorbital distance 5.9 mm ; distance from eye to snout tip 5.8 mm ; nares located lateral on snout, hardly visible from above and closer to tip of snout than to anterior corner of eyes; snout rounded, only slightly oval ( Fig. 1 , b); well developed maxillary teeth, first two teeth on either maxilla particularly prominent; mandibular teeth absent; canthus rostralis rounded but distinct; loreal region slightly concave; round tympanum comparatively large (3.0 mm), 61.2% of eye diameter ( 4.8 mm ) but not distinct, same colour as surrounding area; upper arm length 12.3 mm (28.4% of SVL), forearm length 11.5 mm (26.5% of SVL); fingers without webbing; longest finger 7.5 mm ; relative finger length: 4<1=2<3; subarticular tubercles well defined, large and present on all fingers ( Fig. 2 ); tibula-fibula ( 22.8 mm ) 52.6% of SVL; femur ( 21.7 mm ) 50.1% of SVL; tibiale-fibulare including longest toe 31.5 mm (72.7% of SVL); terminal toe phalanges slightly expanded into discs; subarticular tubercles on toes distinct but smaller than those on fingers; single inner metatarsal tubercle ( 2.7 mm ) slightly more than three quarters of first toe length; relative toe length: 1<2<5<3<4; foot webbing rudimental, almost absent ( Fig. 2 ); skin on dorsum, ventrum and legs smooth, except for urostyle-cloacal region, which is porous to sulcate; gular region smooth, without folds. FIGURE 3. Arthroleptis krokosua sp. nov. holotype (SMNS 12555) in life. Photographs R. Ernst Colour of holotype in life. Dorsal colouration generally light brown to beige without clearly marked patterns ( Fig. 3 ). Head from snout tip to interorbital cream white, forming a bright triangle; interorbital and occipital region slightly darker than rest of dorsum; slightly darker triangular shaped pattern in sacral region; legs with dark banding; one main band on femur, an additional band at level of femur-tibula-fibula joint; three bands on shanks; inside of entire hind extremity dark; only inside of lower arm dark; peculiar row of dark lateral blotches ( Fig. 3 ); the anterior set each bordered by thin white line; first blotch on left side partially fused with the dark tympanal patch; the latter starts behind the eye and broadens subsequently, covering the entire tympanum and extending dorsally and posteriorly; entire patch bordered by thin white line; throat completely dark; dark pigmentation continues across chest and fades caudally; irregular white spots distributed across venter, starting at level of chest ( Fig. 3 ); femur irregularly marbled; distinct dark labial bars underneath eye and naris. Colour of holotype in preservative. Nearly no colour difference between life and preserved specimen. Colour in ethanol only more faded. Distribution and habitat. The species is so far only known from the type locality at Krokosua Hills Forest Reserve. There it was found to be associated with uphill moist semi-deciduous forest. The microhabitat in which it was encountered was characterized by a comparatively thick and dense leaf litter. We recorded no open bodies of water, neither lentic nor lotic, in direct vicinity of the type locality.