The skin structures and their role in the thermoregulation of the South American fur seal (Arctocephalus australis)

Author(s)

da Silva, Ana Paula ^{[1, 2]} ; Machado, Alex S. D. ^{[1, 3]} ; Le Bas, Alfredo E. ^[4] ; Silva, Rodrigo G. ^[1] ; dos Anjos Silva, Elizangela ^{[1, 5]} ; Hernandez-Blazquez, Francisco J. ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Vet Med & Anim Sci, Dept Surg, Sao Paulo - Brazil

^[2] Fed Univ Hlth Sci Porto Alegre, Dept Basic Hlth Sci, Porto Alegre, RS - Brazil

^[3] Fed Univ Jequitinhonha & Mucuri Valleys, Posgrad Program Anim Biol, Diamantina, MG - Brazil

^[4] Univ Uruguay Republ, Fac Sci & Humanity, Dept Physiol, Montevideo - Uruguay

^[5] Univ Fed Mato Grosso do Sul, Inst Biosci, Campo Grande, MS - Brazil

• Document type: Journal article
• Source: Anatomical Record-Advances in Integrative Anatomy and Evolutionary Biology; v. 303, n. 12 JAN 2020.
• Web of Science Citations: 0

Abstract

The skin of the South American fur seal (Arctocephalus australis) is important for animal thermoregulation in both terrestrial and aquatic environments. Skin tissue samples were collected from A. australis for microscopic analysis and were related to anatomical references. The aim of this study was to describe the skin morphology, as well as to suggest the major anatomical regions and skin components involved in the thermoregulation of this species. Using light microscopy, the skin of six animals was examined based on histological, morphometric, and immunohistochemical criteria. Hair follicle morphology was examined using scanning electron microscopy. The skin was classified as either thick or thin based on its epidermal thickness. The thin epidermis regions had more abundant hair follicles, as well as high pigmentation, whereas the thick epidermis regions had very pigmented epidermal layers. Pigmentation of hair and skin is fundamental for protection against ultraviolet rays; moreover, hair is important in preventing abrasion, and provides an insulating layer against the external environment, which can be much colder than body temperature. Furthermore, the dermis is well vascularized, especially the superficial dermis. All regions of the skin have adaptations for maintaining the animal's condition in both terrestrial and aquatic environments. Among the studied regions, the interdigital region from hindflipper showed important morphological characteristics related to thermoregulation, such as having an epidermis of intermediate thickness, a dermis with a small number of hairs, a large amount of blood vessels, and sweat glands with large lumens, indicating that heat exchange in this region may be faster. (AU)

• FAPESP's process: 06/05970-4 - Microscopic study of flipper skin vascularization of South American fur seal (Arctocephalus australis, Zimmermann, 1783)
• Grantee: Rodrigo de Godoi da Silva
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 06/05896-9 - Microscopic architecture of the tegumentar system of the South American fur seal (Arctocephalus australis, Zimmermann, 1783)
• Grantee: Francisco Javier Hernandez Blazquez
• Support Opportunities: Regular Research Grants