title: Thorns and dermal denticles of skates Atlantoraja cyclophora and A. castelnaui: Microscopic features and functional implications.
abstract: Some batoid species are covered with dermal denticles (or placoid scales) that occasionally develop into thorns. In sexually mature males, sharp teeth and alar thorns found on the apex of the lateral disc are used to hold the female during copulation. This study set out to analyze microscopic features of modified dermal denticles and thorns and to investigate sexual dimorphism in Atlantoraja cyclophora and A. castelnaui species. Skin samples collected from areas covered with thorns were fixed in 10% formaldehyde, processed and analyzed using scanning electron microscopy. Alar thorn morphology varied within species, while caudal thorn, rostral and caudal dermal denticle morphology varied within and between species. These structures play an important role in the protection and reproduction of the species studied and constitute important taxonomic information, given they are often the only elements preserved in archaeological sites and fossil records.
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, 321, Cidade Universitária, São Paulo, SP, Brazil.|Departamento de Cirurgia, Central de Facilidades à Pesquisa da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Rua Professor Orlando Marques Paiva, s/n, 05508-270, São Paulo, SP, Brazil.
authors.forename: Bianca de Sousa
authors.initials: BS
authors.lastname: Rangel
authors.affiliation: Departamento de Fisiologia, Setor de Ciências Biológicas, Centro Politécnico, Universidade Federal do Paraná, Curitiba, Paraná, CEP 81531-990, Brazil.
authors.forename: Natascha
authors.initials: N
authors.lastname: Wosnick
authors.affiliation: Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Rua Professor Orlando Marques Paiva, s/n, São Paulo, SP, 05508-270, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Magdanelo Leandro
authors.affiliation: Centro APTA do Pescado Marinho, Instituto de Pesca, APTA, SAA, São Paulo, SP, Brazil.
authors.forename: Alberto Ferreira de
authors.initials: AF
authors.lastname: Amorim
authors.affiliation: Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Rua Professor Orlando Marques Paiva, s/n, São Paulo, SP, 05508-270, Brazil.
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Kfoury Junior
authors.affiliation: Departamento de Cirurgia, Central de Facilidades à Pesquisa da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Rua Professor Orlando Marques Paiva, s/n, 05508-270, São Paulo, SP, Brazil.
authors.forename: Rose Eli Grassi
authors.initials: RE
authors.lastname: Rici
mesh_terms: D000825:Animal Structures / Q000000981:diagnostic imaging / Q000648:ultrastructure; D000818:Animals; D005260:Female; D008297:Male; D008855:Microscopy, Electron, Scanning; D012727:Sex Characteristics; D012860:Skates, Fish / Q000033:anatomy & histology*; D012867:Skin / Q000000981:diagnostic imaging / Q000648:ultrastructure
keywords: eyespot skate; scanning electron microscopy; sexual dimorphism; spotback skate