taxonID	type	description	language	source
6A4A87C4FFDEFFC9D3F6F8C0FB2EF80F.taxon	discussion	Remarks: Stock (1966) described the new species Ammothea depolaris from a location adjacent to Uruguayan waters (RV Calypso cruise 1961 – 1962, station 172, off Buenos Aires Province, Argentina).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDEFFC9D3F6FB95FA82F924.taxon	discussion	Remarks: The description of Tanystylum isthmiacum difficile Stock, 1966 was based on a single female collected at one of nine RV Calypso 1961 – 1962 cruise stations between north Brazil and Buenos Aires Province (Argentina). Owing to a mix-up in material (see Stock 1966), the exact station is not known, and thus its presence in Uruguayan waters is uncertain (Stock 1966). Fage & Stock (1966) and Stock (1975) recorded this subspecies from Cape Verde Islands (eastern Atlantic, 40 m depth) and northern Brazil (at depth between 51 – 93 m) respectively. It was also doubtfully recorded from shallow subtidal waters (6 – 9 m depth) on the Caribbean coast of Panama (Child 1979). Stock (1992) recorded this subspecies from southeast Brazil (19 ° S, 28 m depth). Müller & Krapp (2009) considered T. isthmiacum Stock, 1955 to be a morphologically variable species and did not follow the separation of that species into two subspecies. They also compiled the known distribution of this species in the Eastern Pacific, Western Atlantic and Eastern Atlantic.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDFFFC8D3F6FF55FB0BFEE8.taxon	distribution	Distribution: Antarctica (Scotia Sea; Ross Sea; South Georgia; South Orkney Islands; South Shetland Islands; Antarctic Peninsula); Magellanic region; Malvinas (Falkland) Islands; off La Plata River (Uruguay) (Child 1994 a; Cano-Sánchez & López-González 2014). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, st. 237. Depth 993 – 1011 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDFFFC8D3F6FE74FA35FD0B.taxon	distribution	Distribution: Antarctica (Weddell Sea; Scotia Sea near South Shetland Islands; Ross Sea; Antarctic Peninsula); Magellanic region; Malvinas (Falkland) Islands; coast and off Buenos Aires Province (Argentina); off La Plata River (Uruguay) (Child 1994 a; Albano et al. 2006; Cano-Sánchez & López-González 2014). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, st. 239, referred as 239 A. Depth 1661 – 1679 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDFFFC8D3F6FB04FF4BFAE7.taxon	distribution	Distribution: Antarctica (Scotia Sea); off La Plata River (Uruguay) (Child 1982, 1994 a). Uruguayan records: Child (1982, as A. cuculum): RV Atlantis II, cruise 60, sts 237 and 240). Depth 993 – 2323 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDFFFC8D3F6F98DFF0CF97C.taxon	distribution	Distribution: Only known from off La Plata River (Uruguay). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, sts 237 and 240 (type locality). Depth 993 – 2323 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDFFFC8D3F6FCD8FE69FC6F.taxon	distribution	Distribution: Antarctica (Scotia Sea; Bouvet Islands; Bellingshausen Sea); off La Plata River (Uruguay) (Child 1994 a, 1997; Munilla & Soler – Membrives 2009). Uruguayan records: Child (1982, 1997): RV Atlantis II, cruise 60, sts. 245 and 262, referred as 245 A and 262 A. Depth 2440 – 2707 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD8FFCFD3F6FDE0FE41FAFC.taxon	distribution	Distribution: Rio Grande do Sul (Brazil, 33 ° 50´S – 51 ° 51´W, 65 m) to northern Argentine shelf (down to 40 ° S) (Mañé-Garzón 1944; Stock 1966, 1992; Larramendy 1974). Uruguayan records: Mañé-Garzón (1944): 36 ° 05´S – 53 ° 03´W, 130 m depth (type locality).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD8FFCFD3F6FDE0FE41FAFC.taxon	discussion	Remarks: Stock (1966) reported many specimens of C. geoffroyi collected by the RV Calypso 1961 – 1962 cruise station 172. Due to the mixing of materials, he reported specimens belonging to this species collected in one or more of six additional stations from that cruise (105, 149, 160, 161, 171 and 173) between Rio de Janeiro, Brazil and Buenos Aires Province, Argentina. Larramendy (1974) identified 18 specimens from Argentinean waters (37 ° 23´S – 40 ° 01´S) collected by the RV Walther Herwig (1966 – 1971) as C. geoffroyi. He indicated that these do not differ from the original description, but complemented the description with additional details. Stock (1992) reported one fragmented specimen from the coast of Rio de Janeiro (23 ° 25´S – 43 ° 00´W, 113 m depth), that he assigned with doubts to C. geoffroyi. He commented that “ if … really this species, the range would be considerably extended in northward direction ”. Stock (1992) stated that the material reported by Minnard & Zamponi (1984) as C. geoffroyi seems to belong to a different species, given the differences illustrated by the Argentinean authors: “ tarsus is [illustrated as being] almost twice as long as propodus; in C. geoffroyi both parts are almost equal in length ”. Moreover, the data associated with that material is dubious. The RV Walther Herwig station 340 (cruise 1966) is not at 200 m depth, as reported by Minnard & Zamponi (1984), but 165 m depth; furthermore it is not located off Mar del Plata, as indicated by Stock (1992), but instead is off southern Argentina (53 ° 57´S – 58 ° 46´W). López de Levy (1989) gave a general description of females attributed to C. geoffroyi mañé-garzón, 1944, obtained as by-catch in the commercial fishery off the La Plata River (Uruguay-Argentina, 35 ° – 39 ° S) (López de Levy, pers. comm. to FS 2005).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD8FFCFD3F6FF5AFEC0FE45.taxon	discussion	Remarks: Child (1995 a) commented: “ The Antarctic species of this genus need a thorough revision but I leave this difficult task to a future student of the Pycnogonida. ” He also reported Colossendeis megalonyx ssp. from the shelf and slope off Buenos Aires Province (Argentina) on the basis of material collected by the RV Islas Orcadas (37 ° 24´S – 54 ° 39´7 W, 182 – 327 m). Child recorded great variation in size, and in morphometric relationships between proboscis, femur, and tibia. These considerations, as well as those made below for C. geoffroyi, highlight the need for a revision of Antarctic and Subantarctic species of Colossendeis (Cano & López-González 2007; Krabbe et al. 2010).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD8FFCFD3F6FA0BFF67F956.taxon	distribution	Distribution: Antarctica (Ross Sea); Patagonian shelf (Tierra del Fuego and Malvinas (Falkland) Islands); off La Plata River (Uruguay)? (Child 1995 a). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, st. 242. Depth 4382 – 4402 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD8FFCFD3F6FA0BFF67F956.taxon	discussion	Remarks: This record may represent an undescribed species. Considering that only one specimen was collected, and that species in this genus appears to exhibit great variation, its taxonomic status is uncertain (Child 1997).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD9FFCED3F6FF55FB7AFEE8.taxon	distribution	Distribution: Burdwood Bank; Argentine shelf; South Georgia Islands; off La Plata River (Uruguay and Argentina); Southeast Brazil (23 ° 40´S); southwestern Pacific up to ca. 42 ° S; Palmer Archipelago (Child 1982, 1995 b; Stock 1992; Melzer et al. 2006). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, st. 240. Depth 2195 – 2323 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD9FFCED3F6FB46FBC4FA8C.taxon	distribution	Distribution: Known only from off La Plata River (Uruguay). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, st. 245. Depth 2707 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD9FFCED3F6FA98FB74FA57.taxon	distribution	Distribution: Argentine Basin (Uruguay and Argentina). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, st. 256). Depth 3906 – 3917 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD9FFCED3F6FE3FFF54FBBA.taxon	discussion	Remarks: Stock (1966) recorded one specimen of Nymphon from one of nine stations (4, 40, 69, 105, 149, 160, 161, 171 and 173) of the RV Calypso 1961 – 1962 cruise between north Brazil and Buenos Aires Province (Argentina) which included Uruguayan waters. He later described Nymphon vulcanellum based on a large series from the Brazilian coast between 21 ° 40´S and 28 ° S (21 – 250 m depth) and assigning to this species the referred specimen (Stock 1992). The presence of this species in Uruguayan waters is uncertain. Apart from the several species of Nymphon listed below, Child (1982) recorded a Nymphon specimen based on unidentifiable material (either juvenile or damaged) from RV Atlantis II, cruise 60, sts 237 and 262 (as 262 A) (Argentine Basin off La Plata River) (Child 1982). Loman (1923) recorded Nymphon gracillimum Calman, 1915 from station 2 of the Swedish Antarctic Expedition (1901 – 1903), off Buenos Aires Province, Argentina, 37 ° 30´S – 56 ° 11´W, 100 m depth. Bremec et al. (1986) illustrated and discussed two specimens of N. gracillimum from the littoral zone of the Buenos Aires Province (38 ° 45´S), pointing out differences between their material and the male holotype. This species is considered a junior synonym of Nymphon hiemale Hodgson, 1907, which has an Antarctic distribution (Child 1995 c).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD9FFCED3F6F9F3FAA1F93E.taxon	distribution	Distribution: Known only from off La Plata River (Uruguay). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, sts 237 and 240. Depth 993 – 2323 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD9FFCED3F6F8C5FB7AF824.taxon	distribution	Distribution: From isolated localities in the Pacific and Atlantic oceans; off La Plata River (Uruguay) (Child 1982; Raiskii & Turpaeva 2006). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, st. 243. Depth 3815 – 3822 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6FF7EFAE8FEE8.taxon	distribution	Distribution: Antarctic and Subantarctic waters on both sides of Scotia Sea; off La Plata River (Uruguay) (Child 1995 b, 1997). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, st. 245, referred as 245 A). Depth 2707 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6FE74FAD5FDD7.taxon	distribution	Distribution: Widely distributed in Atlantic basins; off La Plata River (Uruguay); southwestern of Indian Ocean (Child 1982, 1997; Raiskii & Turpaeva 2006). Uruguayan records: Child (1982, 1997): RV Atlantis II, cruise 60, sts 246 and 259. Depth 3305 – 3343 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6FD73FA9EFCDD.taxon	distribution	Distribution: Circumantarctic and Subantarctic; off La Plata River (Uruguay) (Child 1995 b, 1997, 1998; Weis et al. 2011). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, sts 242 and 256. Depth 3906 – 4402 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6FC6EFD2AFBFC.taxon	distribution	Distribution: Circumantarctic and Subantarctic; off La Plata River (Uruguay) (Child 1982, 1995 b, 1997, 1998; Weis et al. 2011). Uruguayan records: Child (1982, 1997): RV Atlantis II, cruise 60, sts 240, 245, 262 and 264, referred as 245 A, 262 A and 264 A. Depth 2041 – 2707 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6FB08FBC4FAC7.taxon	distribution	Distribution: Known only from off La Plata River (Uruguay-Argentina). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, st. 243. Depth 3815 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6FA63FAFFF9AE.taxon	distribution	Distribution: Antarctica (Scotia Sea); off La Plata River (Uruguay) (Child 1997). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, st. 245, referred as 245 A. Depth 2707 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6F9B5FD54F800.taxon	distribution	Distribution: Antarctica (Palmer Archipelago; South Orkney Islands); Pacific Ocean (Hikurangui Trench); off La Plata River (Uruguay) (Child 1982, 1995 b, 1997). Uruguayan records: Child (1982, as N. spicatum, 1997): RV Atlantis II, cruise 60, sts 243 and 245, referred as 245 A. Depth 2707 – 3822 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDAFFCDD3F6F9B5FD54F800.taxon	discussion	Remarks: Described by Child (1982) as Nymphon spicatum n. sp. from the referred stations, but lately synonymized by him (1995 c, 1997) with N. typhlops.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDBFFCCD3F6FF7EFAFFFEB4.taxon	distribution	Distribution: Known only from off La Plata River (Uruguay). Uruguayan records: Child (1997): RV Atlantis II, cruise 60, st. 245, referred as 245 A. Depth 2707 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDBFFCCD3F6F9BEFAB8F85D.taxon	distribution	Distribution: Magellanic Strait?; off La plata river (Uruguay); Northeast Brazil (Bahia to Pernambuco) (Stock 1975; Child 1982). Uruguayan records: Child (1982): RV Atlantis II, cruise 60, sts 236 and 237. Depth 497 – 1011 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDBFFCCD3F6F9BEFAB8F85D.taxon	discussion	Remarks: Pallenopsis meinerti is a somewhat enigmatic species. Based on additional material, Stock (1975) was the first to review this species and he detailed problems with the origin of the type material. This " species " deserves much additional research. As currently understood (Stock 1975; Child 1982), P. meinerti occurs in upper slope depths (specifically 370 – 1101 m) and has been reported only from northeast Brazil (ca. 8 – 9 ° S) and off the La Plata River (ca. 36 ° 30´S), a somewhat anomalous geographic distribution for an upper slope species.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFDBFFCCD3F6FE1BFADFF9A2.taxon	discussion	Remarks: This genus has a long and complex taxonomic history in the southwest Atlantic, summarized by Stock (1973, 1975). Weis et al. (2014) analysed the existence of a species-complex within the traditional concept of Pallenopsis patagonica (Hoek, 1881). In fact, they referred it as “ one of the most taxonomically problematic and variable pycnogonid species known to date ”. Böhm (1879) recorded Pallenopsis fluminensis (Kroyer, 1844) (as Phoxichilidium fluminensis) from the Magellan Strait and Patagonia (54.9 – 76.8 m depth) based on material collected by the RV Gazelle in 1876, deposited in the Museum für Naturkunde der Humboldt-Universität zu Berlin. In the zoological report of the Gazelle expedition, Studer (1889) recorded that species (as Pallene fluminensis) from three stations, adding a third and deeper (80.5 m) record from the Uruguayan shelf. Schimkewitsch (1930) considered that Böhm’s specimens represent a new species: Pallenopsis boehmi. Stock (1973) redescribed this species, re-examining the material identified by Böhm as P. fluminensis (four specimens collected by the Gazelle), but considered that one specimen belongs to P. patagonica. Stock (1973) nominated a female specimen from the Magellan Strait as the Lectotype of P. boehmi. Due to insufficient labelling, it was not possible to establish which locality the specimen of P. patagonica belongs; either it was station LVII, 38 ° 10.1´S – 56 ° 26. 6´W, 54.9 m depth, off Buenos Aires Province, Argentina, or it belongs to station LX, 34 ° 43.7´S – 52 ° 36.1´W, 80.5 m depth, Uruguayan shelf (Stock 1973; Dunlop et al. 2007). Therefore, the records of Studer (1889) for both localities remain uncertain. According to Stock (1973, 1992), P. boehmi has a geographical distribution extending from the Strait of Magellan to southeast Brazil (ca. 23 ° 10´S). This distribution is biogeographically anomalous for a shelf species.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD4FFC3D3F6FA66FAF4F93D.taxon	distribution	Distribution: Widely distributed in tropical and temperate zones of the Atlantic Ocean (including Brazil, Uruguay and Argentina); Mediterranean and Black Seas (Stock 1966, 1975, 1992; Raiskii & Turpaeva 2006; Müller & Krapp 2009; Lehmann et al. 2014; Esquete et al. 2016). Uruguayan records: Carranza et al (2007 a): littoral.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD4FFC3D3F6FA66FAF4F93D.taxon	discussion	Remarks: Wide global distribution and a lengthy synonymy suggest that this name may apply to a species complex; more taxonomic studies are needed for determining its status, either native, exotic or cryptogenic.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD4FFC3D3F6F8C8FB86F807.taxon	distribution	Distribution: Magellan Strait; off La Plata River (Uruguay) (Child 1982, 1995 b). Uruguayan references: Child (1982): RV Vema, cruise 18, st. 9. Depth 676 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD4FFC3D3F6FB65FD96FADA.taxon	discussion	Remarks: Anoplodactylus stictus Marcus, 1940 and Anoplodactylus pygmaeus (Hodge, 1864) have been recorded from the littoral zone of Buenos Aires Province (Argentina) by several authors (e. g. Castellanos 1965; Stock 1966; Bremec et al. 1986; Genzano 2002).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD4FFC3D3F6FF7EFBD2FCBD.taxon	distribution	Distribution: Southeast Pacific, from 33 ° S to the Magellanic Region; Southwest Atlantic to ca. 37 ° 15´S, including the Malvinas (Falkland) Islands and South Georgia Islands; Burdwood Bank; Antarctica (Ross Sea, Weddell Sea) (Weis et al. 2014). Uruguayan records: Hoek (1881, as Phoxichilidium patagonicum var. elegans): HMS Challenger, st. 320. Depth 1097 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD4FFC3D3F6FF7EFBD2FCBD.taxon	discussion	Remarks: Hoek (1881) describes his specimen from st. 320 as probably representing a more elongated individual due to the influence of depth. Child (1995 b), analyzing a large amount of material from the Antarctic and Sub-Antarctic regions, observed that some specimens had more elongated appendages, while others had shorter ones (although he did not determine if the variation occurs in specific localities or is diffused along of region). More recently, Weis et al. (2014), using molecular and morphological data, evaluated the variations found in individuals of P. patagonica from the Antarctic and Subantarctic regions. They observed that P. patagonica represents a large species complex, with at least two clades, a Chilean clade (which they called P. yepayekae Weis, 2014) and a " Falkland " clade, maintained under P. patagonica. It was in this last clade that the individual analysed by Hoek (1881) (Pallenopsis patagonica sensu stricto) was positioned. Child (1995 b) reported material he assigned to this species from the shelf and slope off Buenos Aires Province (Argentina) collected by the RV Islas Orcadas (37 ° 24´S – 54 ° 39´7 W, 182 – 327 m depth).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD5FFC2D3F6FA7EFC3DF8D4.taxon	distribution	Distribution: Antarctica (Scotia Sea; King George Island; South Shetland Islands); Southeast Atlantic; Magellanic region; South Shetland Islands; Argentine Basin; off La Plata River (Uruguay); Brazil Basin; Guiana Basin; Northwest Atlantic; Southeast Pacific (Peru-Chile Trench); Northwest Pacific Ocean (Kurile-Kamtchatka Trench); (Child 1982, 1994 b, 1997; Raiskii & Turpaeva 2006). Uruguayan records: Child (1982, 1997): RV Atlantis II, cruise 60, sts 240, 242, 243, 245, 256 and 262, referred as 245 A and 262 A. Depth 567 – 4402 m.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD5FFC2D3F6FA7EFC3DF8D4.taxon	discussion	Remarks: Turpaeva (1990) recorded Pantopipetta brevicauda Stock, 1963 from a locality very close to Uruguayan waters (36 ° 12.9 ' S – 49 ° 09.7 ' W, i. e., international waters off Brazil) in a depth of 4630 m (RV Akademik Kurchatov, station 4893, cruise 43). We agree with Child (1982, 1994 b) and Bamber & Thurston (1995) in considering P. brevicauda a junior synonym of P. longituberculata.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD5FFC2D3F6FE80FBDCFD84.taxon	discussion	Remarks: Pycnogonum elephas Stock, 1966 was described from material of uncertain locality due to the mixing of samples collected at one or more RV Calypso 1961 – 1962 cruise stations (105, 149, 160, 161, 171 and 173) between Rio de Janeiro (Brazil) and Buenos Aires Province (Argentina), including Uruguayan waters. There have been no further records. The presence of this species in Uruguayan waters is uncertain.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD5FFC2D3F6FDA3FCC0FB1E.taxon	distribution	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. 2007 a; Müller & Krapp 2009). Uruguayan records: Carranza et al. (2007 a, as P. pamphorum): littoral.	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
6A4A87C4FFD5FFC2D3F6FDA3FCC0FB1E.taxon	discussion	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).	en	Scarabino, Fabrizio, Lucena, Rudá Amorim, Munilla, Tomás, Soler-Membrives, Anna, Ortega, Leonardo, Schwindt, Evangelina, López, Guzmán, María, José, Christoffersen, Martin Lidsey (2019): Pycnogonida (Arthropoda) from Uruguayan waters (Southwest Atlantic): annotated checklist and biogeographic considerations. Zootaxa 4550 (2): 185-200, DOI: 10.11646/zootaxa.4550.2.2
