Rotundopotamonautes, (BOTT, 1955)

Cumberlidge, Neil & Daniels, Savel R., 2022, A new multilocus phylogeny reveals overlooked diversity in African freshwater crabs (Brachyura: Potamoidea): a major revision with new higher taxa and genera, Zoological Journal of the Linnean Society 194 (4), pp. 1268-1311 : 1298-1299

GENUS ROTUNDOPOTAMONAUTES ( BOTT, 1955) STAT. NOV.

( FIGS 1B 3 [5], 6D–F, 10E; TABLES 1–3 )

Zoobank registration: urn:lsid:zoobank.org:act:3E8357A3-511E-47C4-AC50-29671ADE964D .

Thelphusa Audouin, 1826: 82 , pl. 2, fig. 6; H. Milne Edwards, 1837: 14; 1853: 212–213; White, 1847: 30; Heller, 1861: 19; Herklots, 1861: 13; A. Milne-Edwards, 1869: 177; 1869: 176, pl. 9 Fig. 1 ; 1887: 137; Kingsley, 1880: 35; Bell, 1894: 166; Ortmann, 1897: 312.

Cancer (Thelphusa) De Haan, 1833: 23 .

Geothelphusa Stimpson, 1861: 373; Hilgendorf, 1898: 20.

Telphusa Pfeffer, 1888: 33 ; Henderson, 1893: 284.

Potamon (Potamonautes) Ortmann, 1897: 310 , 312.

Potamon De Man, 1898: 436 ; Flower, 1931: 732; Chace, 1942: 207; Capart, 1954: 827, figs 4, 31.

Potamon (Geothelphusa) Rathbun, 1904 : pl. 18, figs 3, 10; Rathbun, 1905: 203–204; Lenz, 1910 b: 124 (4); De Man, 1914: 126, 127, pl. 2: fig. 3, fig. 3a; Colosi, 1919: 50; Colosi, 1920: 34; Balss, 1929 b: 350; Rathbun, 1935: 25.

Potamonautes (Rotundopotamonautes) Bott, 1955: 288 –289 , pl. 23, fig. 5, pl. 23, fig. 1a–d; Monod, 1980: 382–383, pl. V, fig. 28 (not Potamonautes (Rotundopotamonautes) infravallatus = Arcopotamonautes infravallatus ).

Potamonautes (Lobopotamonautes) Bott, 1955 : pl. XVIII, figs 2a, 3a; pl. XX, fig. 2a–d, figs 1, 2, 48, 50, 87, 88, 89 [partim: for Potamon (Potamonautes) aloysiisabaudiae Nobili, 1906 , not Potamon (Potamonautes) stanleyensis Rathbun, 1921 , Potamon (Geothelphusa) perparvus Rathbun, 1921 , Po. perparvus gonocristatus Bott, 1955 , Po. perparvus minor Bott, 1955 ].

Potamonautes Cumberlidge, 1997: 579 ; Cumberlidge, 1998: 197–198; Ng et al., 2008: 171; Cumberlidge et al., 2009: appendix 1, 19; Cumberlidge, 2009b: 548, 551– 557, tab. 1; Cumberlidge & Meyer, 2010: 180, 184, 187, tab. 1.

Diagnosis: Third maxilliped ischium smooth, lacking vertical sulcus; thoracic sternal sulcus S3/4 incomplete, deep only at sides, interrupted in middle; cheliped carpus inner margin proximal tooth reduced to small granule; G1 TA distinctly widened in midsection (dorsal fold higher than ventral fold), tip curved upward.

Type species: Thelphusa berardi Audouin, 1826 , by original designation.

Species included: Rotundopotamonautes alluaudi ( Bouvier, 1921) comb. nov., Rotundopotamonautes aloysiisabaudiae (Nobili, 1906) comb. nov., Rotundopotamonautes amalerensis ( Rathbun, 1935) comb.nov., Rotundopotamonautesantheus ( Colosi,1920) comb. nov., Rotundopotamonautes berardi (Audouin, 1826) comb. nov., Rotundopotamonautes bipartitus ( Hilgendorf, 1898) comb. nov., Rotundopotamonautes bourgaultae ( Cumberlidge & Meyer, 2009) comb. nov., Rotundopotamonautes busingwe ( Cumberlidge & Clark, 2017) comb. nov., Rotundopotamonautes bwindii ( Cumberlidge & Clark, 2018) comb. nov., Rotundopotamonautes elgonensis ( Cumberlidge & Clark, 2010a) comb. nov., Rotundopotamonautes emini (Hilgendorf, 1892) comb. nov., Rotundopotamonautes entebbe ( Cumberlidge & Clark, 2017) comb. nov., Rotundopotamonautes gonocristatus ( Bott, 1955) comb. nov., Rotundopotamonautes holthuisi ( Cumberlidge & Meyer, 2009) comb. nov., Rotundopotamonautes ignestii (Parisi, 1923) comb. nov., Rotundopotamonautes imatongensis ( Cumberlidge & Clark, 2016) comb. nov., Rotundopotamonautes jeanneli ( Bouvier, 1921) comb. nov., Rotundopotamonautes kantsyore ( Cumberlidge & Clark, 2017) comb. nov., Rotundopotamonautes kivu ( Cumberlidge & Clark, 2018) comb. nov., Rotundopotamonautes kundudo ( Cumberlidge & Clark, 2012) comb. nov., Rotundopotamonautes loashiensis ( Bott, 1955) comb. nov., Rotundopotamonautes loveni (Colosi, 1924) comb. nov., Rotundopotamonautes minor ( Bott, 1955) comb. nov., Rotundopotamonautes morotoensis ( Cumberlidge & Clark, 2016) comb. nov., Rotundopotamonautes mutandensis ( Chace, 1942) comb. nov., Rotundopotamonautes neumanni ( Hilgendorf, 1898) comb. nov., Rotundopotamonautes odhneri (Colosi, 1924) comb.nov., Rotundopotamonautes perparvus ( Rathbun, 1921) comb. nov., Rotundopotamonautes pilosus ( Hilgendorf, 1898) comb. nov., Rotundopotamonautes rodolphianus (Rathbun, 1909) comb. nov., Rotundopotamonautes rothschildi (Rathbun, 1909) comb. nov., Rotundopotamonautes rukwanzi ( Corace, Cumberlidge & Garms, 2001) comb. nov., Rotundopotamonautes rwenzori ( Cumberlidge & Clark, 2018) comb. nov., Rotundopotamonautes subukia ( Cumberlidge & Dobson, 2008) comb. nov. and Rotundopotamonautes williamsi ( Cumberlidge & Clark, 2010a) comb. nov.

Distribution: The range of Rotundopotamonautes centres on Uganda, Kenya and Ethiopia, with the border between Kenya and Tanzania serving as the south-eastern boundary line and Sudan and Egypt the northern boundary ( Fig. 10E ). The distribution also includes the central and northern parts of the Rift Valley around Lakes Tanganyika, Kivu and Victoria and their drainages [D.R. Congo (Nord-Kivu and Ituri provinces), Rwanda, Burundi, Tanzania (Kagoro Province)] and South Sudan ( Chace, 1942; Corace et al., 2001; Cumberlidge, 2004, 2009b; Cumberlidge & Dobson 2008; Cumberlidge & Clark, 2010a, b, 2012, 2016, 2017, 2018; Cumberlidge & Meyer, 2010, 2011).

Remarks: The subgenus Rotundopotamonautes of Bott (1955) is raised here to genus rank. This genus is established to accommodate 36 species of Potamonautes from the Nile River Basin, Lake Kivu, Uganda, Kenya, Ethiopia, South Sudan, Sudan and Egypt. Bott (1955) established Po. ( Rotundopotamonautes ) for seven taxa: Po. loveni (as Po. granviki ), Po. infravallatus , Po. semilunaris, Po. emini, Po. loashiensis, Po. berardi and Po. ignestii . Six of these (including Po. berardi ) are assigned to this revised genus, with the exception of Po. infravallatus , which is here transferred to Arcopotamonautes . The name Rotundopotamonautes is retained because it includes the type species of the subgenus Po. ( Rotundopotamonautes ), Thelphusa berardi Audouin, 1826 . One of the species included here in Rotundopotamonautes is Potamon (Potamonautes) aloysiisabaudiae Nobili, 1906 , from Uganda, the type species of Potamonautes (Lobopotamonautes) Bott, 1955 . This latter subgenus is treated here as a junior synonym of Rotundopotamonautes under the rule of priority because Potamon (Potamonautes) lirrangensis Rathbun, 1904 , is the senior name. DNA data are available for only six of these species: R. kundudo , R. loveni , R. rukwanzi , R. alluaudi , R. odhneri and R. subukia . The molecular phylogenies group these species together in a well-supported clade within the larger clade for Potamonautes s.s. ( Fig. 1B 3 ; Daniels et al., 2015: fig. 1; Daniels & Klaus, 2018: fig 1; Wood et al., 2019: fig. 1).The other 29 species are included here based on shared morphological characters that conform to the genus diagnosis. For example, all of the species in this distinctive genus have a faint, incomplete postfrontal crest that does not traverse the carapace, reduced or absent exorbital and epibranchial teeth, and a smooth anterolateral margin of the carapace behind the epibranchial tooth.

Figures

Figure 1. A, maximum clade credibility tree of the Afrotropical freshwater crab fauna based on four DNA loci with support values (posterior probabilities and bootstrap values of the ML analyses) with a geological timescale below the tree topology. Posterior probabilities> 0.95 pP (*above branch) and bootstrap values> 75% (* below branch) were regarded as statistically supported and are shown on the tree topology. Clade A, Liberonautinae, clade B, Potamonautinae, clade B1, Maritimonautini, clade B2, Erimetopini, clade B3, Potamonautini. B, detail of the maximum clade credibility tree of the Afrotropical freshwater crab fauna showing Clade B3 Potamonautini with the species included in the five genera within the tribe: Arcopotamonautes (B3[1]), Lirrangopotamonautes (B3[2]), Platythelphusa (B3[3]), Potamonautes s.s. (B3[4]) and Rotundopotamonautes (B3[5]).

Figure 3. Gonopods 1 and 2 of four genera in Liberonautinae. A–C, Buea asylos (Cumberlidge et al., 2019: fig. 7a, d; 8a); D–F, Potamonemus mambilorum (Cumberlidge et al., 2019: fig. 7b, e; 8b); G–I, Sudanonautes floweri; J–L, Louisea balssi (Mvogo Ndongo et al., 2018: fig. 5a–c, © Magnolia Press, reproduced with permission from the copyright holder). A, D, G, J, left G1 ventral view; B, E, H, K, left G1 dorsal view; C, F, I, L, left G2 ventral view. Scale bar: A, B, D, E, G, H, J, K = 2.0 mm, C, F, I, L = 1.8 mm.

Figure 10. Maps showing the distributional ranges of the five genera of Potamonautini. (A) Arcopotamonautes, (B) Lirrangopotamonautes, (C) Platythelphusa, (D) Potamonautes s.s. and (E) Rotundopotamonautes.