title: Morphology of the eyeball from the Humpback whale (Megaptera novaeangliae).
abstract: Aquatic mammals underwent morphological and physiological adaptations due to the transition from terrestrial to aquatic environment. One of the morphological changes regards their vision since cetaceans' eyes are able to withstand mechanical, chemical, osmotic, and optical water conditions. Due to insufficient information about these animals, especially regarding their sense organs, this study aimed to describe the morphology of the Humpback whale (Megaptera novaeangliae) eyeball. Three newborn females, stranded dead on the coast of Sergipe and Bahia, Brazil, were used. Samples were fixed in a 10% formalin solution, dissected, photographed, collected, and evaluated through light and electron microscopy techniques. The Humpback whale sclera was thick and had an irregular surface with mechanoreceptors in its lamina propria. Lens was dense, transparent, and ellipsoidal, consisting of three layers, and the vascularized choroid contains melanocytes, mechanoreceptors, and a fibrous tapetum lucidum. The Humpback whale eyeball is similar to other cetaceans and suggests an adaptation to diving and migration, contributing to the perception of differences in temperature, pressure, and lighting.
authors.affiliation: Faculdade Pio Décimo, Campus III, Av. Tancredo Neves, 5655, Bairro Jabotiana, Aracaju, Sergipe, Brasil; Núcleo de Estudo dos Efeitos Antropogênicos nos Recursos Marinhos/Fundação Mamíferos Aquáticos, Av. Tancredo Neves, 5655, Bairro Jabotiana, Aracaju, Sergipe, Brasil.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Rodrigues
authors.forename: Fernanda M O
authors.initials: FM
authors.lastname: Silva
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Trompieri-Silveira
authors.forename: Jociery E
authors.initials: JE
authors.lastname: Vergara-Parente
authors.forename: Maria Angélica
authors.initials: MA
authors.lastname: Miglino
authors.forename: Juliana P
authors.initials: JP
authors.lastname: Guimarães
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000033:anatomy & histology / Q000648:ultrastructure; D002829:Choroid / Q000033:anatomy & histology / Q000648:ultrastructure; D002924:Ciliary Body / Q000033:anatomy & histology / Q000648:ultrastructure; D003315:Cornea / Q000033:anatomy & histology / Q000648:ultrastructure; D005123:Eye / Q000033:anatomy & histology* / Q000648:ultrastructure; D005260:Female; D050640:Humpback Whale / Q000033:anatomy & histology*; D007498:Iris / Q000033:anatomy & histology / Q000648:ultrastructure; D007908:Lens, Crystalline / Q000033:anatomy & histology / Q000648:ultrastructure; D008853:Microscopy; D008854:Microscopy, Electron; D009900:Optic Nerve / Q000033:anatomy & histology / Q000648:ultrastructure; D012160:Retina / Q000033:anatomy & histology / Q000648:ultrastructure; D012590:Sclera / Q000033:anatomy & histology / Q000648:ultrastructure
keywords: Megaptera novaeangliae; aquatic mammals; eye; ultrastructure