ERIMETOPINI, Cumberlidge & Daniels, 2022

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 : 1290

ERIMETOPINI TRIBE NOV.

( FIGS 1B 2 , 4A–L, 8C; TABLES 1–3 )

Zoobank registration: urn:lsid:zoobank.org:act:61AF1486-7B40-4EC9-A244-6875EAD2C1CE .

Diagnosis: Third maxilliped ischium smooth, lacking vertical sulcus; epibranchial tooth small, pointed; postfrontal crest distinct, completely traversing carapace.

Etymology: Erimetopini is derived from a combination of the English words Congo and West, as a reference to the range of this tribe that includes an area that encompasses the Congo Basin and all of West Africa ( Fig. 8C ). The gender is masculine.

Type genus: Erimetopus Rathbun, 1894 .

G e n e r a i n c l u d e d: E r i m e t o p u s R a t h b u n, 1 8 9 4, Longipotamonautes ( Bott, 1955) stat. nov., Nesonautes gen. nov. and Occidensonautes gen. nov.

Distribution: Erimetopini is found in West and Central Africa in the following countries: Erimetopus occurs in the Republic of the Congo and the D.R. Congo ( Fig. 9A ), Longipotamonautes occurs in Nigeria, Cameroon, the D.R. Congo, the Central African Republic, Gabon and the Republic of the Congo ( Fig. 9B ), Nesonautes is endemic to São Tomé Island ( Fig. 9C ) and Occidensonautes is found in West Africa from Senegal to Nigeria ( Fig. 9D ).

Remarks: Each of the four genera in this tribe has been recovered as a well-supported lineage in the clade for Erimetopini ( Fig. 1B 2 ) and these relationships are also supported by other recent molecular studies of these taxa ( Daniels & Klaus, 2018: fig. 1; Wood et al., 2019: fig. 1). The genera can be distinguished from each other by differences in the G1 TA ( Fig. 4A–L ; see key to genera above).

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 4. Gonopods 1 and 2 of the four genera in Erimetopini. A–C, Erimetopus vandenbrandeni; D–F, Longipotamonautes ballayi; G–I, Nesonautes margaritarius; J–L, Occidensonautes ecorssei. Scale bar: A–L = 2.0 mm.

Figure 8. Maps showing the distributional ranges of (A) Potamonautinae, (B) Maritimonautini, (C) Erimetopini and (D) Potamonautini.

Figure 9. Maps showing the distributional ranges of the four genera of Erimetopini (A) Erimetopus, (B) Longipotamonautes, (C) Nesonautes and (D) Occidensonautes.

Figure 2. Liberonautinae. Gonopods 1 and 2 of Liberonautes latidactylus, NMU9.V.2005B (CW 72, CL 47.2, CH 20.5, FW 19.3 mm) Guinea, West Africa. A, left G1 ventral view; (B) left G1 dorsal view; (C) left G2 ventral view. Scale bar: A, B = 2.8 mm, C = 1.8 mm.