Monday, February 12, 2018

[Herpetology • 2018] Letheobia akagerae • A New Blind Snake of the Genus Letheobia (Serpentes: Typhlopidae) from Rwanda with Redescriptions of L. gracilis and L. graueri and the Introduction of A Non-invasive Preparation Procedure for Scanning Electron Microscopy in Zoology


Letheobia akagerae
Dehling, Hinkel, Ensikat, Babilon & Fischer, 2018


Abstract

A new species of blind snake in the genus Letheobia is described from Akagera National Park in eastern Rwanda. The new species is most similar to species of the L. gracilis complex, particularly L. gracilis and L. graueri. It differs from all other species of the genus by a unique combination of morphological characters, including the highest number of middorsal scale rows (834) and the most extreme elongation (total-length/midbody-width ratio 131) of all species in the genus and of any species of snake in the world; 22-22-22 longitudinal scale rows; snout in dorsal profile rounded, in lateral profile bluntly rounded with an angular horizontal edge ventrally; rostral broad, posteriorly rounded; eyes invisible; supralabial imbrication pattern T-0; tail short (1.3 percent of total length) with an apical spine; and a pink life colouration. The holotype of the new species was collected in gallery forest at a lake shore surrounded by savanna at 1300 m elevation. We produced scanning electron microscope images of the heads of the investigated specimens applying a liquid-substitution preparation procedure which does not require coating or drying and thus does not irreversibly damage the investigated samples. The obtained images allow an easy and more accurate examination of the scalation.

Keywords: Reptilia, Taxonomy, morphology, Letheobia gracilis, Letheobia graueri, Akagera National Park, liquid substitution, glycerol, uncoated specimens, SEM of liquids, infiltration


FIGURE 4. Holotype of Letheobia akagerae sp. nov. (ZFMK 100862) in life.


Etymology. The specific epithet refers to the type locality, the Akagera National Park in eastern Rwanda.

Distribution, habitat and conservation status. The holotype of Letheobia akagerae was found when soil was dug during construction work. The type locality is in gallery forest near the shores of Lake Ihema at around 1290 m a.s.l. Three additional specimens were observed and photographed in tree savanna on a nearby hilltop in the headquarters area of the national park slithering on the ground after heavy rainfalls during the day. All of them showed the extreme elongation of the body and a pinkish live colouration but unfortunately none were retained for further examination. The species may be more widespread and even occur in cultivated areas outside the national park. Until further data on the distribution and abundance of the species becomes available, we recommend L. akagerae be classified as Data Deficient according to the IUCN Red List Criteria ( IUCN 2017).


J. Maximilian Dehling, Harald H. Hinkel, Hans-Jürgen Ensikat, Kenny Babilon and Eberhard Fischer. 2018. A New Blind Snake of the Genus Letheobia (Serpentes: Typhlopidae) from Rwanda with Redescriptions of L. gracilis (Sternfeld, 1910) and L. graueri (Sternfeld, 1912) and the Introduction of A Non-invasive Preparation Procedure for Scanning Electron Microscopy in Zoology. Zootaxa. 4378(4); 480–490. DOI:  10.11646/zootaxa.4378.4.2

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