Osteology of Tucanoichthys tucano Gery and Ramer, an enigmatic miniature fish from the Amazon basin, Brazil (Teleostei: Characiformes: Characidae)

Autor(es)

Mattox, George M. T. ^[1] ; Conway, Kevin W. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Biol, Lab Ictiol Sorocaba, Campus Sorocaba, BR-1852780 Sao Paulo - Brazil

^[2] Texas A&M Univ, Dept Ecol & Conservat Biol & Biodivers Res & Teac, 2258 TAMU, College Stn, TX 77843 - USA

• Tipo de documento: Artigo Científico
• Fonte: VERTEBRATE ZOOLOGY; v. 71, p. 645-667, OCT 18 2021.
• Citações Web of Science: 0

Resumo

Miniaturization, the evolution of extremely small adult body size, is a common phenomenon across the lineages of freshwater fishes, especially in the Neotropics where over 200 species are considered miniature (<26 mm in standard length {[}SL]). Close to 30% of all miniature Neotropical freshwater fishes belong to the family Characidae, several of which are of uncertain phylogenetic placement within the family. We investigate the skeletal anatomy of Tucanoichthys tucano, a species of uncertain phylogenetic position from the upper Rio Negro basin, reaching a maximum known size of 16.6 mm SL. The skeleton of Tucanoichthys is characterized by the complete absence of ten skeletal elements and marked reduction in size and/or complexity of others, especially those elements associated with the cephalic latero-sensory canal system. Missing elements in the skeleton of Tucanoichthys include those that develop relatively late in the ossification sequence of the non-miniature characiform Salminus brasiliensis, suggesting that their absence in Tucanoichthys can be explained by a simple scenario of developmental truncation. A number of the reductions in the skeleton of Tucanoichthys are shared with other miniature characiforms, most notably species of Priocharax and Tyttobrycon, the latter a putative close relative of Tucanoichthys based on molecular data. (AU)

• Processo FAPESP: 18/22592-0 - Viva rápido, morra jovem na Amazônia: testando predições sobre história de vida nos menores vertebrados amazônicos através de colaboração internacional entre TAMU e UFSCar
• Beneficiário: George Mendes Taliaferro Mattox
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/01970-4 - Integrando dados morfológicos e moleculares no estudo taxonômico e filogenético do peixe miniatura Priocharax Weitzman & Vari (Teleostei, Characiformes, Characidae)
• Beneficiário: George Mendes Taliaferro Mattox
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores