The female holotype measures 20 mm SVL. A conical papilla is present on the anterior quarter of the tongue. Head wider than long. Tympanum distinct, measuring just under half the diameter of the eye. Nostril equidistant from eye and tip of the snout. Interorbital space as broad as the upper eyelid. Limbs are short. Tibiotarsal articulation reaching the axilla, with the 4th toe extending beyond the tip of the snout. Fingertips barely dilated, without discs. Finger I shorter than Finger II. Toes free, slightly swollen at the tip but without actual discs. Sub-articular tubercles rather large, very prominent. Inner metatarsal tubercle is large, oval, very prominent, as long as the inner toe, and warty. Skin granular, dotted with small warts on the back, snout, and tibia. Posterior half of the posterior belly and thighs are covered with warts, while the throat, chest, and ventral surfaces of the tibia and tarsi are smooth. Males have thin spines along the inner edge of Fingers II and III, and a small disc of skin in the gular region (Angel 1950).
The reddish brown coloration resembles that of Arthroleptis poecilonotus; markings may or may not be present, and may consist of a triangular patch followed by two diamonds, with the posterior diamond being the larger of the two. The legs have traces of transverse bands. Throat, chest, and anterior belly are mottled with reddish brown. A thin white vertebral stripe, from snout to vent, may be present (Angel 1950).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Guinea
Endemic to Mount Nimba, Guinea. It may also occur on the Liberian and Ivorian parts of Mount Nimba, but this has not been confirmed (Stuart et al. 2008). The elevational range of this species is 500-1,650 m asl (Angel 1950). Arthroleptis crusculum can be found in high altitude grasslands (savanna), on the edges of marshes and in gallery forest (Angel 1950).
Life History, Abundance, Activity, and Special Behaviors
It breeds by direct development (Guibé and Lamotte 1958).
Trends and Threats
Arthroleptis crusculum was formerly an abundant and common species; habitat loss and degradation are likely contributing to population diminishment, although there have been no recent surveys of this species. Both "slash-and-burn agricultural activities" and "extensive iron-ore mining operations" are threatening habitat on Mt. Nimba. It occurs in at least one protected area, the Mount Nimba Strict Nature Reserve, which is a World Heritage Site (Stuart et al. 2008).
Possible reasons for amphibian decline
General habitat alteration and loss
Further research and field work needs to be done to determine the status of this species (Stuart et al 2008).
Angel, F. (1950). ''Arthroleptis crusculum et A. nimbaense. Batraciens nouveaux de Guinée française. (Matériaux de la Mission Lamotte aux Monts Nimba).'' Bulletin du Muséum national d'histoire naturelle, 22(5), 559-562.
Guibé, J. and Lamotte, M. (1958). ''Morphologie et reproduction par developpement direct d'un anoure du Mont Nimba, Arthroleptis crusculum Angel.'' Bulletin du Muséum National d’histoire Naturelle, Série 2, 20, 125-133.
Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., and Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
Written by Krystal Gong (mskgong AT sfsu.edu), SFSU
First submitted 2009-05-11
Edited by Kellie Whittaker (2010-04-07)
Species Account Citation: AmphibiaWeb 2010 Arthroleptis crusculum: Guinea Screeching Frog <http://amphibiaweb.org/species/5889> University of California, Berkeley, CA, USA. Accessed Nov 16, 2018.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 16 Nov 2018.
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