Hemicentetes semispinosus, the streaked tenrec, is one of 23 extant species of the clade Tenrecidae (Nowak, 1991). Tenrecs are small mammals (head and body length: 40-400 mm) and many, but not all, have greatly reduced tails and bodies covered with bristly hair or quills (Nowak, 1991).

Recent analyses of molecular data place Tenrecidae in the clade Afrotheria which also includes aardvarks, elephants, hyraxes, golden moles, elephant shrews, and sirenians (Murphy et al., 2001). Within Afrotheria, tenrecs form a clade with golden moles and elephant shrews (Murphy et al., 2001). Some analyses of morphological data place Tenrecidae as the sister taxon to golden moles (Asher, 1999).

All tenrecs are endemic to Africa; this includes Madagascar, western and central equatorial Africa, and the Comoro Islands (Nowak, 1991). The streaked tenrec is found only in Madagascar (Marshall and Eisenberg, 1996). The subspecies H. s. semispinosus is found in rainforests and H. s. nigriceps lives in the central, upland region (Marshall and Eisenberg, 1996:1). The fossil record of Tenrecidae extends from Miocene - Recent in mainland Africa, and Pleistocene - Recent in Madagascar (Nowak, 1991).

Hemicentetes semispinosus is a smallish tenrec (head and body length about 140 mm) with spiny pelage that is black with a median stripe on the head and three stripes running along the length of the back of the body (Marshall and Eisenberg, 1996:1). The subspecies H. s. semispinosus has yellow stripes while H. s. nigriceps has white stripes (Marshall and Eisenberg, 1996).

The skull of Hemicentetes semispinosus has an elongate rostrum, a reduced zygoma, and reduced dentition (Marshall and Eisenberg, 1996). The occlusal surface of the molars are zalambdodont and the dental formula is i 3/3, c 1/1, p 3/3, m 3/3, total 40 (Marshall and Eisenberg, 1996).

Hemicentetes semispinosus is active year round; H. s. semispinosus can be active any time of day but H. s. nigriceps is strictly nocturnal (Nowak, 1991; Marshall and Eisenberg, 1996). The streaked tenrec primarily feeds on earthworms and refuges in short, shallow burrows. When disturbed, H. semispinosus will raise the quills on the back of its head and sometimes chatter or squeak (Marshall and Eisenberg, 1996). Ten species of tenrecs are listed as critical, endangered, or vulnerable by IUCN, but H. semispinosus is not one of them.

This specimen was collected from Ivohibe, Madagascar. It was made available to The University of Texas High-Resolution X-ray CT Facility for scanning by Ted Macrini of The University of Texas at Austin courtesy of the American Museum of Natural History. Funding for scanning was provided by a National Science Foundation Dissertation Improvement Grant (DEB-0309369) to Mr. Macrini. Funding for image processing was provided by a National Science Foundation Digital Libraries Initiative grant to Dr. Timothy Rowe of The University of Texas at Austin.

Specimen Photos

ventral view	lateral view	close-up of head

This specimen was scanned by Matthew Colbert on 25 November 2003 along the coronal axis for a total of 427 slices. Each slice is 0.0669 mm thick, with an interslice spacing of 0.0669 mm and a field of reconstruction of 48 mm.

Literature

Asher, R. J. 1999. A morphological basis for assessing the phylogeny of the “Tenrecoidea” (Mammalia, Lipotyphla). Cladistics 15:231-252.

Asher, R. J. 2001. Cranial anatomy in tenrecid insectivorans: character evolution across competing phylogenies. American Museum Novitates 3352:1-54.

Marshall, C. D., and J. F. Eisenberg. 1996. Hemicentetes semispinosus. Mammalian Species 541:1-4.

Murphy, W. J., E. Eizirik, S. J. O’Brien, O. Madsen, M. Scally, C. J. Douady, E. Teeling, O. A. Ryder, M. J. Stanhope, W. W. de Jong, and M. S. Springer. 2001. Resolution of the early placental mammal radiation using Bayesian phylogenetics. Science 294:2348-2351.

Nowak, R. M. 1991. Walker’s Mammals of the World. Volume 1. Fifth edition. The Johns Hopkins University Press, Baltimore.

Links

Information and images of Hemicentetes semispinosus (Ranomafana National Park).

Images of the brain of H. semispinosus on the Commparative Mammalian Brain Collection.

Information about the streaked tenrec on the Animal Diversity Web (Univ. of Michigan Museum of Zoology).

None available.