Lirrangopotamonautes, (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 : 1294-1295

GENUS LIRRANGOPOTAMONAUTES ( BOTT, 1955) STAT. NOV.

( FIGS 1B 3 [2], 5G–I, 10B; TABLES 1–3 )

Zoobank registration: urn:lsid:zoobank.org:act:D8A4F4AA-99CB-4EF3-B381-BBF9E2F182BE .

Potamon (Potamonautes) lirrangensis Rathbun, 1904 : pl. 14, fig. 8; 1905: 169; 1921: 413–415, pls 25, 26, figs 3, 8; Balss, 1914: 404; 1929: 347–348 (partim, not D.R. Congo: Kituri, Upper Lualaba, Katanga Province, Russisi River, Lake Kivu); 1936: 188–189 (partim, not D.R. Congo: Banana, Lakes Kivu, Mweru).

Potamon lirrangensis Chace, 1942: 188–189 ; Capart, 1954: 836, fig. 28.

Potamonautes (Lirrangopotamonautes) lirrangensis Bott, 1955: 268–269 (partim, not Lake Kivu, Kindu, Lokandu, Kinshasa, Buta, Lubo, Lulua, Luzizi, Ruzizi rivers, Luvungu, Lake Tanganyika (Mpala, Uvira), Lake Malawi).

Potamonautes lirrangensis Cumberlidge, 1998: 264 (partim, not Tanzania: Tukuyu (formerly Neu-Langenburg); Malawi: Lake Malawi; Reed & Cumberlidge, 2006a (partim, not Tanzania: Kigoma area, Taveta, Mungonya River, Uvinza, Malagarasi River, Malawi: Lake Malawi); Ng et al., 2008: 171 (partim).

Potamonautes (Tripotamonautes) Bott, 1955: 264 , pl. XIV, figs 2a–d, 32, 33 [partim: for Potamon (Potamonautes) walderi Colosi, 1924 , not Potamon (Potamonautes) loveridgei Rathbun, 1933 ].

Diagnosis: Postfrontal crest distinct, completely traversing carapace between epibranchial teeth; exorbital tooth small, epibranchial tooth reduced to small granule; cheliped carpus with two subequal long teeth, cheliped merus with large pointed distal meral tooth; third maxilliped ischium smooth, lacking vertical sulcus (or with faint vertical sulcus); thoracic sternal sulcus S3/4 deep, completely traversing sternum (or deep only at sides, faint in middle).

Type species: Potamon (Potamonautes) lirrangensis Rathbun, 1904 , by original designation.

Species included: Lirrangopotamonautes congoensis ( Rathbun, 1921) comb. nov., Lirrangopotamonautes didieri ( Rathbun, 1904) comb. nov., Lirrangopotamonautes dybowskii ( Rathbun, 1905) comb. nov., Lirrangopotamonautes kisangani (Cumberlidge et al., 2021) comb. nov., Lirrangopotamonautes lirrangensis ( Rathbun, 1904) comb. nov. s.s., Lirrangopotamonautes lueboensis ( Rathbun, 1904) comb. nov.

Lirrangopotamonautes niloticus (H. Milne Edwards, 1837) comb. nov., Lirrangopotamonautes stanleyensis ( Rathbun, 1921) comb. nov.

Lirrangopotamonautes walderi (Colosi, 1924) comb. nov.

Distribution: The range of Lirrangopotamonautes is centred on the Congo River in the D.R. Congo including the Middle Congo ( Lr. kisangani, Lr. congoensis, Lr. didieri and Lr. stanleyensis are found in the provinces of Tshopo, Haut-Uele, Bas-Uele and Ituri, Lr. lirrangensis and Lr. dybowskii are found in the province of Equateur, Lr. lueboensis is found in the Lower Congo provinces of Kwango, Kwilu and Kasai and Lr. walderi is found in Central Province ( Chace, 1942; Bott, 1955; Corace et al., 2001; Cumberlidge, 2015; Cumberlidge et al., 2021; Fig. 10B ). Lr. niloticus is found in the entire Nile River drainage from its upper reaches in Rwanda and Lake Victoria to Uganda, Kenya, South Sudan, Ethiopia, Sudan and Egypt ( Cumberlidge & Clark, 2010a).

Remarks: The subgenus Potamonautes (Lirrangopotamonautes) Bott, 1955 is given genus status and is revised to accommodate 12 species from the Middle and Upper Congo River Basin, Uganda, Tanzania and lakes Tanganyika and Kivu. Bott (1955) established Po. ( Lirrangopotamonautes ) for Po. (Lr.) lirrangensis, Po. (Lr.) johnstoni johnstoni and Po. (Lr.) johnstoni platycentron . Of these, only Po. (Lr.) lirrangensis s.s. (Cumberlidge et al., 2021) is included here, while Po. (Lr.) johnstoni and Po. (Lr.) platycentron are transferred to Arcopotamonautes .

Lirrangopotamonautes includes the type species of the subgenus Potamon (Potamonautes) lirrangensis Rathbun, 1904 . In addition, Lirrangopotamonautes also includes Potamon (Potamonautes) walderi Colosi, 1924 , the type species of the subgenus Potamonautes (Tripotamonautes) Bott, 1955 . The latter subgenus becomes a junior synonym of Po. ( Lirrangopotamonautes ) under the rule of priority because Potamon (Po.) lirrangensis Rathbun, 1904 is the senior name. Furthermore, Lr. niloticus was assigned by Bott (1955) to Po. (Acanthothelphusa) Bott, 1955, as the type species of that subgenus (as Thelphusa nilotica H. Milne Edwards, 1837 ). This now becomes a junior synonym of Lirrangopotamonautes , because Potamon (Po.) lirrangensis was described earlier.

Although DNA data are available for only three of these species ( Lr. niloticus, Lr. stanleyensis and Lr. sp. nov. 6) the molecular phylogenies group these species together in a well-supported clade within the Potamonautini ( Fig. 1B 3 [2]; Daniels et al., 2015: fig. 2; Daniels & Klaus, 2018: fig 1; Wood et al., 2019: fig 1). The other species are included in Lirrangopotamonautes based on shared morphological characters that conform to the diagnosis for the genus. Notably, Lr. niloticus , which diverged early in this clade, differs in that it has pointed exorbital and epibranchial teeth, large spines lining the anterolateral margins, and the cheliped carpus inner margin has a long pointed distal tooth and a distinctly smaller proximal 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.