Platythelphusa conculcata Cunnington, 1907

Reed, Sadie K. & Cumberlidge, Neil, 2006, Brachyura: Potamoidea: Potamonautidae, Platythelphusidae, Deckeniidae (), Zootaxa 1262 (1), pp. 1-139 : 1-139

18. Platythelphusa conculcata Cunnington, 1907 (Fig. 190, plate XVIII)

Platythelphusa conculcata Cunningtion, 1907: 273 , pl. 13, fig. 2,4; Chace, 1942: 225; Capart, 1952: 60.

Potamonautes (Platythelphusa) armata conculcata — Bott, 1955: 228–229, fig. 10a, b, pl. 2, 2a–d (part only); Coulter, 1991: 253–255, tables 9.XX, 9.XXI.

Platythelphusa conculcata: Cumberlidge, 1997: 584 ; 1999: 277; Cumberlidge et al., 1999: 1504– 1506, fig. 3, 7e, 8c, k–l, 9c, 10i–k; Marijnissen et al., 2004: 528–530, Tables 1, 2.

Type material examined: ZAMBIA: Lake Tanganyika , south end, male holotype (cw 10.8 mm), ( BMNH 1908.1.31.15) .

Additional material examined: DEMOCRATIC REPUBLIC OF CONGO: Lake Tanganyika , Uvira, 2 males, 6 females, 21.v.1955 (W. L. Schmitt) ( USNM 98921 ) .

Diagnosis. Carapace subhexagonal, rounded, very flat (ch/fw 0.8). Frontal margin granular with distinct forward pointing tooth at each external corner. Exorbital tooth directed forward, pointed, epibranchial tooth large, pointed. Three large, subequal forward­pointing teeth on anterolateral margin behind epibranchial tooth. Suborbital margin lined by small teeth, larger tooth at medial end. Margins of inferior surface of merus of cheliped lined by small granules, single large pointed tooth on medial inferior margin. Inner margin of carpus of cheliped with two large subequal carpal teeth, articular tooth (at point of articulation with propodus) sharp, pointed; outer margin of carpus lined by row of small thin sharp spines. Merus of p5 about as long as fw, distal tooth on superior margin of p2–p5 sharp, pointed. Propodus of p4 and p5 long, thin, margins of propodus of p5 widened, smooth. Terminal article of gonopod 1 directed sharply outward at a 90° angle to the vertical, slim, cone­shaped, tapering to pointed tip.

Size. Adult size range from cw 15 to cw 21.8 mm.

Distribution. Endemic to Lake Tanganyika: Burundi, Zambia and D. R. Congo, from depths between 20– 60 m.

Remarks. This species was redescribed by Cumberlidge et al. (1999), who provided details of its identification, distribution and ecology. Bott (1955) considered P. conculcata to be a subspecies of P. armata . Platythelphusa conculcata was recognized by Cumberlidge et al. (1999) and by Marijnissen et al. (2004) as a valid species following comparison of the type material of P. armata and P. conculcata .

Natural history and conservation status. The conservation status of P. conculcata is categorized as least concern (LC) ( Table 4) because it has a range of occurrence and area of occupancy in excess of the thresholds for vulnerable (VU) ( IUCN 2004). Its population is estimated to be stable based on indirect measures such as the fact that a lot of material has been collected recently from more than one locality (S. Marijnissen, pers. comm.) and that it is well represented in museum collections