Museu de Zoologia da Universidade de São Paulo, Ipiranga, São Paulo, Brazil.
Instituto de Biologia, Universidade Federal da Bahia, Salvador, Bahia, Brazil.
J Fish Biol. 2020 May;96(5):1077-1086. doi: 10.1111/jfb.14096. Epub 2019 Jul 31.
This study aims to investigate relationships between species traits and publication date in the weakly electric osteoglossiform Mormyroidea (African knifefish and elephantfishes) and the ostariophysan Gymnotiformes (Neotropical knifefishes). It is investigated whether body size and geographic distribution area are correlated with publication date and whether extinction risk differs between both phylogenetically distant and geographically isolated clades. Statistical modelling indicates that the number of new species described annually is stable in mormyroids and clearly increasing in gymnotiforms. Best-fitting generalised linear models (GLM) indicate that the newly discovered species are more often of small-bodied, predominantly narrowly distributed and more likely to be threatened with extinction. These characteristics are more pronounced in mormyroids when compared with gymnotiforms, suggesting that some African electric fishes may live an ephemeral existence after formal description. Despite taxonomic work has been more intense in the Neotropics than in Africa in the recent decades, there is evidence that the African continent represents the next frontier of species descriptions. Taxonomic studies are fundamental for the understanding of richness and distribution and hence extinction risk assessment and conservation, of these remarkable convergent fish clades.
本研究旨在探讨弱电骨舌鱼目(非洲刀鱼和象鼻鱼)和南美电鳗目(新热带刀鱼)的物种特征与发表日期之间的关系。研究了体型大小和地理分布范围是否与发表日期相关,以及灭绝风险是否在两个系统发育上相距甚远和地理上孤立的分支之间存在差异。统计模型表明,每年描述的新物种数量在骨舌鱼目鱼类中是稳定的,而在电鳗目鱼类中则明显增加。最佳拟合的广义线性模型(GLM)表明,新发现的物种通常体型较小,分布范围较窄,更有可能受到灭绝威胁。与电鳗目鱼类相比,这些特征在骨舌鱼目鱼类中更为明显,这表明一些非洲电鱼在正式描述后可能会短暂存在。尽管在最近几十年中,分类学工作在新热带地区比在非洲更为集中,但有证据表明非洲大陆代表着物种描述的下一个前沿。分类学研究对于理解这些显著趋同鱼类分支的丰富度和分布以及因此评估灭绝风险和保护至关重要。