Diversity, distribution and new records of freshwater and estuarine shrimp in the state of Amapá, eastern Brazilian Amazon region Author Vieira, Inacia Maria 0000-0002-6911-0780 Programa de Pós-Graduação em Biodiversidade e Biotecnologia (BIONORTE), Universidade Federal do Amapá, Macapá, AP, Brasil. Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá - IEPA. & inaciavieira 2011 @ gmail. com; https: // orcid. org / 0000 - 0002 - 6911 - 0780 inaciavieira2011@gmail.com Author Silva, Luiz Maurício Abdon Programa de Pós-Graduação em Biodiversidade e Biotecnologia (BIONORTE), Universidade Federal do Amapá, Macapá, AP, Brasil. Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá - IEPA. Author Almeida, Alini Gomes Santiago De 0000-0002-9773-489X alinigsantiago @ gmail. com; https: // orcid. org / 0000 - 0002 - 9773 - 489 X alinigsantiago@gmail.com Author Almeida, Danilo Pelaes De Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal do Amapá, Macapá, AP, Brasil. Author Silva-Júnior, Orleno Marques 0000-0002-1173-1429 orlenomarques @ yahoo. com. br; https: // orcid. org / 0000 - 0002 - 1173 - 1429 orlenomarques@yahoo.com.br Author Tavares-Dias, Marcos Programa de Pós-Graduação em Biodiversidade e Biotecnologia (BIONORTE), Universidade Federal do Amapá, Macapá, AP, Brasil. Instituto de Pesquisas Científicas e Tecnológicas do Estado do Amapá - IEPA. & Embrapa Amapá, Macapá, AP, Brasil. text Zootaxa 2022 2022-08-24 5178 1 41 71 journal article 129872 10.11646/zootaxa.5178.1.3 6329ab0a-3a78-4998-aae3-bf28b87876bb 1175-5326 7021864 4DECF608-22E1-4049-9271-F20E5E0ECB49 Leander tenuicornis (Say, 1818 [in Say, 1817-1818) Examined material. Municipality of Calçoene : Mouth of Cassiporé River , State of Amapá ( 03°52’53,40”N , 51°08’36,03”W ), 1 male and 1 female ( IEPA1625 ) ( Figure 2 ) . Geographic distribution. Western Atlantic Ocean - Canada , USA ( Massachusetts , Virginia , Carolina, Florida, Louisiana and Texas ), Bermudas , Mexico , Panama , Bahamas , Cuba , Jamaica , Porto Rico , Island Virginia, Colombia , Venezuela , Brazil (states of Maranhão , Piauí , Ceará , Rio Grande do Norte , Paraíba , Pernambuco [Atol das Rocas], Alagoas , Sergipe , Bahia , Espírito Santo , Rio de Janeiro and São Paulo ), Malvinas Islands. Eastern Atlantic Ocean: Azores archipelago, Portugal . Mediterranean- Spain , France , Italy and Libya . Pacific and Indian Ocean - Red Sea, India , Japan , Papua New Guinea , Australia and New Zealand ( Ferreira et al. 2010 ; Herrera-Barquín et al. 2018 ; Ramos-Porto 1985 ). Distribution in Amapá state . Estuary of the Cassiporé River. Previous records. present study Ecological notes. Species found in shallow waters, up to 72 m deep, on gravel, sandy bottoms with algae meadows and/or phanerogams ( Ramos-Porto 1985 ). In the Cassiporé River estuary, it was found in mangrove areas and river with very mud. Remarks. Leander tenuicornis presents sexual dimorphism in relation to the shape of the face, in the female the rostrum is wider in the ventral part ( Ferreira et al. 2010 ).