The hair structure of the long-eared gymnure (Otohylomys megalotis)

O.F. Chernova, V.F. Kulikov and A.V. Abramov

Proceedings of the Zoological Institute RAS, 2015, 319(3): 428–440 · https://doi.org/10.31610/trudyzin/2015.319.3.428

Full text

Abstract

Weak degree of hair differentiation and microstructure of hair and whiskers of Otohylomys megalotis are similar to those in Hylomys suillus and Neotetracus sinensis: there are spear-shaped lead hairs and zigzag guard hairs of three orders, downy hairs are missing. In O. megalotis: 1) hairs are longer than those of other gymnures; 2) thin convoluted hair bases bound up contributing to the formation of the inert layer of air near the surface of the skin, improves the thermal insulation properties of hair in the absence of downy hairs; 3) strength in thinnest areas of the shaft (at its base and excesses) is provided by thickening of its cuticular scales, the special interconnection between cuticle and cortex, and cruciform layout of medulla discs in these places; 4) the pineal cuticular ornament of hair bases is characteristic of all three species of gymnures and resembles that of other insectivores, as well as of some marsupials and carnivores that reflects similar hair adaptations to the habitats; 5) for the first time discovered specialized pyramidal medulla of vibrissae, stiffening a shaft that is necessary for effective transfer of mechanical impulses to nerve cells of vibrissae follicle and functioning of whiskers as a tactile organ; 6) a long proboscis with well-developed nasal vibrissae and also numerous long whiskers on muzzle, neck, wrists and forearms are important and effective for the O. megalotis orientation in complex terrain karst habitats.

Key words

long-eared gymnure, vibrissae, hair, microstructure, SEM, topography

Submitted January 26, 2015 · Accepted August 31, 2015 · Published September 25, 2015

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