MARITIMONAUTINI, 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 : 1285-1286

MARITIMONAUTINI TRIBE NOV.

( FIGS 1B1 , 5A–C , 8B; TABLES 1–3)

Zoobank registration: urn:lsid:zoobank.org:act:C6FA3FDB-7C33-4AE0-9AB8-5C4BBDD4C19E .

Diagnosis: S3/4 deep, V-shaped, completely traversing sternum (or deep at margins, faint in the middle); outer margins of S4 raised and thickened; third maxilliped ischium lacking vertical suture (or if present, faint); anterolateral margin of carapace posterior to epibranchial tooth either smooth or granulated, but lacking teeth; G1 TA short (TA length 0.25 × SA length), slim, either not widened in midsection (or dorsal fold slightly higher than ventral fold), tapering evenly to pointed tip ( Fig. 5A, B ).

Etymology: Maritimonautini is derived from the genus-level name Maritimonautes .

Type genus: Maritimonautes gen. nov., gender masculine.

Genus included: Maritimonautes .

Distribution: Maritimonautes is found mainly in the low-lying eastern coastal region of Africa (an area of about 200–300 km wide inland from the coast as far as the Rift Valley) including Somalia, Kenya, Tanzania (from the east coast of Africa to the north coast of Lake Malawi, including Tanzania plus Zanzibar and Pemba Islands), Mozambique and South Africa ( Fig. 8C ).

Remarks: The molecular phylogeny presented here ( Fig. 1 ) agrees with the phylogenies of Daniels & Klaus (2018) and Wood et al. (2019), each of which recovered the species assigned here to Mauritonautini as a well-supported clade that forms a distinct lineage ( Fig. 1B1 ) at the base of the large and diverse clade of Potamonautinae ( Fig. 1B ). Mauritonautini ( Fig. 1B1 ) split from the other lineages ( Fig. 1B 2 , B3) in this subfamily over 27 Mya during the Oligocene-Miocene.

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 5. Gonopods 1 and 2 of one genus in Maritimonautini and three genera in Potamonautini. A–C, Maritimonautes obesus; D–F, Arcopotamonautes suprasulcatus; G–I, Lirrangopotamonautes dybowskii; J–L, Platythelphusa armata. Scale bar: A, B, G–L = 2.0 mm, C, F = 1.8 mm; D, E = 5.0 mm; L = 6.7 mm.

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

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.