Ferreira Katiane M, Faria Érika de, Ribeiro Alexandre C, Santana JÚlio C O, Quagio-Grassioto Irani, Menezes NaÉrcio A
Universidade Federal de Mato Grosso, Instituto de Biociências, Departamento de Biologia e Zoologia, Laboratório de Ictiologia, Av. Fernando Correia da Costa, 2367, Boa Esperança, 78060-900, Cuiabá, MT, Brazil..
Zootaxa. 2018 Apr 27;4415(1):161-172. doi: 10.11646/zootaxa.4415.1.8.
Gephyrocharax machadoi, new species, is described from tributaries of the rio Sepotuba, upper rio Paraguai basin, Mato Grosso state, Brazil. The new species is distinguished from its congeners, except Gephyrocharax major, by presenting two modified scales on the ventral caudal-fin lobe (pouch scales): a larger, sexually dimorphic scale, slightly superior and anterior in position, followed by a smaller, posterior and ventrally placed accessory scale (vs. a single modified pouch scale without ventrally placed accessory scales). Gephyrocharax machadoi differs from G. major by presenting a gap (more conspicuous in mature males than in mature females) between the second and third ventral procurrent caudal-fin rays (vs. second and third ventral procurrent caudal-fin rays near each other or fused distally); premaxilla with tricuspid teeth (vs. tetra- to pentacuspid teeth); and body depth 21.5-25.4% of SL (vs. 25.9-36.8% in SL). Spermiogenesis and spermatozoa morphology are also described.
马查多氏细脂鲤，新物种，采自巴西马托格罗索州上巴拉圭河盆地塞波图巴河的支流。该新物种与其同属物种不同，除了大细脂鲤外，其尾鳍腹叶有两片特化鳞片（袋状鳞片）：一片较大，具有两性异形，位置略高于且靠前，后面跟着一片较小的、位于后方且靠腹侧的附属鳞片（与之相对的是单一特化袋状鳞片且无腹侧附属鳞片）。马查多氏细脂鲤与大细脂鲤的区别在于，第二和第三根腹侧尾鳍前向鳍条之间有间隙（成熟雄性比成熟雌性更明显）（与之相对的是第二和第三根腹侧尾鳍前向鳍条彼此靠近或在远端融合）；前颌骨有三尖齿（与之相对的是四尖至五尖齿）；体深为标准体长的21.5 - 25.4%（与之相对的是标准体长的25.9 - 36.8%）。还描述了精子发生过程和精子形态。
