Extension range of four species of freshwater crabs (Decapoda: Trichodactylidae) in the state of Maranhão, Northeastern Brazil

Abstract The present study provides a list of the freshwater crab species of the family Trichodactylidae recorded from the state of Maranhão, northeastern Brazil, along with information about their distribution. Eight streams were sampled with dip nets, sieves, gill nets, and drag nets. Four species were found: Dilocarcinus septemdentatus (Herbst, 1783), Goyazana castelnaui H. Milne Edwards, 1853, Sylviocarcinus pictus (H. Milne Edwards, 1853), and Valdivia serrata White, 1847. Our results increase the known distribution range of these species and add new records to more basins.

摘要 本研究整理了巴西东北部马拉尼昂州（Maranhão）记录的毛指蟹科（Trichodactylidae）淡水蟹物种名录，并附带其分布相关信息。本次研究采用捞网、筛网、刺网及拖网对八条溪流开展采样调查，共记录到四个物种：七齿双齿蟹（*Dilocarcinus septemdentatus* (Herbst, 1783)）、卡氏戈亚斯蟹（*Goyazana castelnaui* H. Milne Edwards, 1853）、华丽西尔维蟹（*Sylviocarcinus pictus* (H. Milne Edwards, 1853)）以及锯齿瓦尔迪维亚蟹（*Valdivia serrata* White, 1847）。本研究结果拓展了上述物种的已知分布范围，并为多个流域新增了分布记录。