Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations Author Scarabino, Fabrizio Author Lucena, Rudá Amorim Author Munilla, Tomás Author Soler-Membrives, Anna Author Ortega, Leonardo Author Schwindt, Evangelina Author López, Guzmán Author María, José Author Christoffersen, Martin Lidsey text Zootaxa 2019 2019-01-24 4550 2 185 200 journal article 27492 10.11646/zootaxa.4550.2.2 2c967830-701d-424c-a044-d61885a8c2c5 1175-5326 2625249 AB41359C-FDBB-483C-B538-BD8D51F42FA2 Pycnogonum cessaci Bouvier, 1911 Distribution: East Pacific ( Panama ); West Atlantic ( Uruguay ; Brazil ; Antilles; Venezuela ; Colombia ; Panama ; SE coast of USA ); East Atlantic (tropical coast of Africa, Cape Verde Is.) ( Stock 1975 , 1990 , 1992 ; Child 1979 ; Carranza et al . 2007a ; Müller & Krapp 2009 ). Uruguayan records: Carranza et al . (2007a , as P. pamphorum ): littoral. Remarks: Pycnogonum pamphorum Marcus, 1940 and P. leticiae Mello-Leitão, 1945 are junior synonyms of P. cessaci , according to Stock (1975 , 1992 ) and Child (1979) . P. cessaci has an amphi-Atlantic distribution (east and west) in the tropics and subtropics ( Stock 1990 , Müller & Krapp 2009 ) and in the Pacific coast of Panama ( Child 1979 ). It is also found in shallow waters among algae, hydroids, bryozoans and sponges, which are organisms commonly found in fouling communities in shallow-water marine systems. These communities are particularly composed by species that occur in different oceans which are commonly transported through different human commercial activities, such as shipping and aquaculture. There is no obvious natural dispersal mechanisms to explain the amphi-Atlantic distribution of P. cessaci . Its presence in fouling communities and its biogeographical history, which does not permit us to ascribed it as being native or exotic, lead us to suspect is that this represents a cryptogenic species (following definition by Carlton 1996 , 2009 ).