Departamento de Biologia Estrutural e Funcional, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, Brazil.
Departamento de Bioestatística, Biologia Vegetal, Parasitologia e Zoologia, Instituto de Biociências, Universidade Estadual Paulista, Botucatu, Brazil.
J Fish Biol. 2021 Mar;98(3):668-679. doi: 10.1111/jfb.14607. Epub 2020 Dec 15.
The Neotropical catfish genus Kronichthys contains three species distributed along coastal rivers of southern and southeastern Brazil. Although phylogenetic hypotheses are available, the molecular and morphological diversity and species boundaries within the genus remain unexplored. In this study, the authors generated mitochondrial data for 90 specimens combined with morphometric and meristic data to investigate species diversity, species boundaries and putative morphological signatures in Kronichthys. Phylogenetic and species delimitation results clearly show the presence of four genetic lineages, three within Kronichthys heylandi along the coast from Rio de Janeiro to southern São Paulo and a single lineage encompassing both the nominal species Kronichthys lacerta and Kronichthys subteres from the Ribeira de Iguape basin to Santa Catarina in southern Brazil. Nonetheless, morphological data show overlapped ranges in morphometrics and a definition of only two morphotypes, with clear phenotypic differences in the teeth number: K. heylandi differs from K. subteres + K. lacerta by the higher number of premaxillary teeth (30-52 vs. 19-28) and higher number of dentary teeth (28-54 vs. 17-28). Headwater captures and connections of paleodrainages because of sea-level fluctuations represent the two major biogeographic processes promoting species diversification and lineage dispersal of Kronichthys in the Atlantic coastal range of Brazil.
南美肺鱼科 Kronichthys 属包含 3 个物种，分布于巴西南部和东南部沿海水系的河流中。尽管已经有了系统发育假说，但该属的分子和形态多样性以及物种界限仍未得到探索。在这项研究中，作者结合形态计量学和可数性状数据生成了 90 个样本的线粒体数据，以调查 Kronichthys 中的物种多样性、物种界限和潜在的形态特征。系统发育和物种划分结果清楚地显示出存在四个遗传谱系，其中三个谱系分布在里约热内卢到南圣保罗的 Kronichthys heylandi 沿岸，而单一谱系则包含来自伊瓜佩流域的名义物种 Kronichthys lacerta 和 Kronichthys subteres 以及巴西南部圣卡塔琳娜州。尽管如此，形态数据显示形态计量学的范围有重叠，并且只有两种形态型定义，牙齿数量存在明显的表型差异：K. heylandi 与 K. subteres + K. lacerta 的区别在于前上颌齿数量较高（30-52 对 19-28）和下颌齿数量较高（28-54 对 17-28）。由于海平面波动导致的源头捕获和古水系连接是促进 Kronichthys 物种多样化和谱系扩散的两个主要生物地理过程，在巴西大西洋沿海地区。
