Cleaning the mud: Integrative approach clarifies the taxonomy of mud crabs of the genus Panopeus H. Milne Edwards, 1834 (Decapoda: Brachyura: Panopeidae) along the Southwestern Atlantic Author Oliveira-Rogeri, Lucas Author França, Nielson Felix Caetano Author Peres, Pedro Augusto Author Mantelatto, Fernando L. text Zoologischer Anzeiger 2023 2023-11-30 307 96 124 http://dx.doi.org/10.1016/j.jcz.2023.10.001 journal article 10.1016/j.jcz.2023.10.001 1873-2674 10661087 3.7. Panopeus rugosus A. Milne-Edwards, 1880 ( Fig. 1G , 10 A-L) Panopeus rugosus A. Milne-Edwards, 1880: 314 , pl. 57, Fig. 4 ; Benedict and Rathbun, 1891: 383 ; Rathbun, 1900: 15 ; Rathbun, 1930: 348 , pl. 162–163; Rathbun, 1933: 61 ; Coelho and Ramos, 1972: 190 ; Abele and Kim, 1986: 51; Melo, 1996: 375 ; Almeida et al., 2006: 15 ; Coelho et al., 2008: 34 ; Melo, 2008: 11 ; Ng et al., 2008: 191 ; Felder et al., 2009: 1082 ; Marochi and Masunari, 2011: 25 ; Alves et al., 2012: 945 ; Thoma et al., 2014: 96 ; Mantelatto et al., 2020: 76 . 3.7.1. Type material Not available. Possibly lost after the Prussian bombardment of Paris, which hit the museum and its zoology service building ( Milne-Edwards, 1880 ). Type-locality: Brazil : Bahia . 3.7.2. Material examined Brazil : Sergipe : 1 female (CW 36.76 mm ), MOUFPE 5883 , Rio Sergipe , iv.1982 . – S˜ao Paulo : 1 male (CW 50.11 mm ) and 2 female (CW 41.95 mm and 43.56 mm ), CCDB 6488 , S˜ao Vicente , 14.ii.2011 ; 2 male (CW 51.36 mm and 54.30 mm ) and 1 female (CW 36.35 mm ), CCDB 736 , Cananeia , 24 ◦ 59’27.1’’S , 47 ◦ 53’43.3’’W , 30.viii.2011 ; 1 male (CW 49.3 mm ), CCDB 6411 , Cananeia , 25 ◦ 01’22’’S , 47 ◦ 55’48’’W , 08. xi.2011 . Fig. 4. Panopeus americanus Saussure, 1857 . A, D, E = syntype male (MHNG 16422), Guadeloupe; B, C, F–H, L-N = male (CCDB 2227; CW = 17.8 mm), Rio de Janeiro, Brazil; I = male (CCDB 4445; CW = 21.3 mm), Par´a, Brazil; J = male (CCDB 6602; CW = 22.6 mm), Maranh˜ao, Brazil; K = female (CCDB 2227; CW =18.2 mm), Rio de Janeiro, Brazil. (A) General dorsal view of Panopeus americanus syntype. (B, D) Front, dorsal view. (C, E) Anterolateral margin of the carapace, dorsal view. (F) Cheliped, outer view. (G) Third maxilliped, view of the inner surface. (H) Fourth pereopod, lateral view. (I) G1 apex, mesial lateral view (coloured image was generated on a stereomicroscope; grayscale image was produced on a CT-scan equipment). (J) Carapace, dorsal view. (K) Right vulva. (L) Carapace, frontal view. Blue arrow indicates the carpal groove. (M) Thoracic sternum and pleon, carapace ventral view. (N) Sixth pleonite, view of the inner surface. Scale bars (mm): B, L = 2; C, F = 5.5; G, N = 2; H = 2.5; I = 0.25; J = 11; K = 0.5; L, M = 4. 3.7.3. Diagnosis Front developed and remarkably quadrilobed with prominent outer lobes, median sinus deep. Rough dorsal surface of carapace with distinct thick granulation pattern, particularly in the medial (1M, 2M), anterolateral (1L, 2L, 3L, 4L, 5L) and postero-lateral (1 R , 2 R ) carapace regions; transverse granulate striations prominent. Anterolateral margin of carapace consisting of five teeth. First inconspicuous and separated by a large and shallow sinus from the second; third tuberculiform, fourth triangular and fifth more similar to a spine than to a tooth. Chelipeds very rough and thick granulated, especially carpus and propodus. Carpal groove parallel to the distal margin of the segment present. Fingers deeply grooved. Pigmented spot on the inner surface of third maxilliped ischium absent. Sternites 3 and 4 with thick and sparse granules. Width of pleonite 6 greater at the distal end than at the proximal end; length: width ratio of pleonite 6 greater than 0.70; socket of pleonal locking mechanism not reaching the half of pleonite 6. Trilobed structure of gonopod apex present. Lateral tooth of first gonopod singular. Vulva more than half the length of the sternite 6; vulva with ovate shape. 3.7.4. Distribution Western Atlantic – United States (Florida), Gulf of Mexico, Antilles, Caribbean Sea, north of South America and Brazil ( Pernambuco , Sergipe , Bahia , S˜ao Paulo, Paran´a, Santa Catarina ) ( Marochi and Masunari, 2011 ; Mantelatto et al., 2020 ). 3.7.5. Remarks Although this species is known for being typically estuarine, Almeida et al. (2008) found some specimens in freshwater environment. This record was obtained from the Santana River ( 14 ◦ 51’07.4"S , 39 ◦ 04’12.8"W ), in the Brazilian state of Bahia , which is also the type-locality for the species. Furthermore, the photo of a P. rugosus specimen presented by Almeida et al. (2008 , Fig. 9 , p. 1248) strongly resembles our P. rugosus specimens suggesting that those specimens truly correspond to this species and were not misidentified.