Systematic Implications of Brain Morphology in Potamotrygonidae (Chondrichthyes: Myliobatiformes)

Autor(es)

Fontenelle, Joao Pedro ^[1] ; de Carvalho, Marcelo R. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Toronto, Dept Biol Sci, Scarborough Campus, 1265 Mil Trail, Off s552, Toronto, ON M1C 1A4 - Canada

^[2] Univ Sao Paulo, Inst Biociencias, Dept Zool, Rua Matao Travessa 14, 101, BR-05508090 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Morphology; v. 277, n. 2, p. 252-263, FEB 2016.
• Citações Web of Science: 6

Resumo

The gross brain morphology, brain proportions, and position of cranial nerves in all four genera (Potamotrygon, Plesiotrygon, Paratrygon, and Heliotrygon) and 11 of the species of the Neotropical stingray family Potamotrygonidae were studied to provide new characters that may have a bearing on internal potamotrygonid systematics. The brain was also studied in four other stingray (Myliobatiformes) genera (Hexatrygon, Taeniura, Dasyatis, and Gymnura) to provide a more inclusive phylogenetic context for the interpretation of features of the brain in potamotrygonids. Our results indicate, based on neuroanatomical characters, that the genera Paratrygon and Heliotrygon are sister groups, as are the genera Potamotrygon and Plesiotrygon, agreeing with previous morphological and molecular phylogenetic studies. Both groups of genera share distinct conditions of the olfactory tracts, telencephalon and its central nuclei, hypophysis and infundibulum, morphology and orientation of the metencephalic corpus cerebelli, orientation of the glossopharyngeal nerve, and overall encephalic proportions. The corpus cerebelli of Paratrygon and Heliotrygon is interpreted as being more similar to the general batoid condition and, given their phylogenetic position highly nested within stingrays, is considered secondarily derived, not plesiomorphically retained. Our observations of the corpus cerebelli of stingrays, including Hexatrygon, corroborate that the general stingray pattern previously advanced by Northcutt is derived among batoids. The morphology of the brain is shown to be a useful source of phylogenetically informative characters at lower hierarchical levels, such as between genera and species, and thus, has significant potential in phylogenetic studies of elasmobranchs. (C) 2015 Wiley Periodicals, Inc. (AU)

• Processo FAPESP: 12/05391-5 - Evolução molecular de regiões regulatórias de genes HOX associados com a morfologia da nadadeira de peixes, com especial ênfase em Chondrichthyes
• Beneficiário: Marcelo Rodrigues de Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/02349-8 - Revisão taxonômica da família Gymnuridae (Chondrichthyes: Myliobatoidei)
• Beneficiário: Marcelo Rodrigues de Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/09877-0 - Estudo comparativo da morfologia do aparelho alimentar em raias da ordem Myliobatiformes (Chondrichthyes: Batoidea)
• Beneficiário: Marcelo Rodrigues de Carvalho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/01240-7 - Estudo anatômico do encéfalo e nervos cranianos de representantes da família Potamotrygonidae (Chondrichthyes: Myliobatiformes): implicações taxonômicas e filogenéticas
• Beneficiário: João Pedro Fontenelle de Araújo Freire da Silva
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica