Universidade Estadual do Maranhão - UEMA, Departamento de Química e Biologia, Programa de Pós-Graduação em Recursos Aquáticos e Pesca, São Luís, MA, Brasil.
Universidade Estadual do Maranhão - UEMA, Laboratório de Genética e Biologia Molecular - GENBIMOL, Caxias, MA, Brasil.
Braz J Biol. 2021 Mar 5;82:e232868. doi: 10.1590/1519-6984.232868. eCollection 2021.
The "piaussu", Megaleporinus macrocephalus is an anostomatid fish species native to the basin of the Paraguay River, in the Pantanal biome of western Brazil. However, this species has now been recorded in a number of other drainages, including those of the upper Paraná, Uruguay, Jacuí, Doce, Mucuri, and Paraíba do Sulrivers. This study presents two new records of the occurrence of M. macrocephalus, in the basins of the Itapecuru and Mearim rivers in the state of Maranhão, in the Brazilian Northeast. The piaussu is a large-bodied fish of commercial interest that is widely raised on fish farms, and its occurrence in the Itapecuru and Mearim rivers is likely the result of individuals escaping from fish tanks when they overflow during the rainy season. Morphological analyses and sequences of the Cytochrome Oxidase Subunit I (COI) gene confirmed the taxonomic identification of the specimens as M. macrocephalus. The COI sequences were 99.66% similar to those of M. macrocephalus deposited in the BOLDSystems database. These records extend the known distribution of M. macrocephalus to the basins of the Itapecuru and Mearim rivers in the Brazilian Northeast, highlighting a new case of introduction of exotic fish species into Brazilian river basins.
巨脂鲤，又名“皮雅苏”，是一种分布于巴拉圭河流域的脂鲤科鱼类，原产于巴西西部潘塔纳尔湿地。然而，如今该物种已在多个其他流域被发现，包括上巴拉那河、乌拉圭河、雅库伊河、道塞河、穆库里河和帕拉伊巴河。本研究报告了在巴西东北部马拉尼昂州的伊塔佩库鲁河和梅拉伊姆河流域发现巨脂鲤的两个新记录。巨脂鲤是一种具有商业价值的大型鱼类，广泛在养殖场养殖，其在伊塔佩库鲁河和梅拉伊姆河的出现可能是由于雨季期间鱼缸溢出，导致个体逃脱。形态分析和细胞色素氧化酶亚基 I（COI）基因序列证实了标本的分类学鉴定为巨脂鲤。COI 序列与 BOLDSystems 数据库中存储的巨脂鲤的序列相似度为 99.66%。这些记录将巨脂鲤的已知分布范围扩展到了巴西东北部的伊塔佩库鲁河和梅拉伊姆河流域，突出了一种新的外来鱼类进入巴西河流域的案例。
