Mesocnemis robusta (Selys, 1886)
Northern Riverjack

Type locality: Sudan, no locality data available.

Diagnosis

Similar to other Mesocnemis species by (a) Ax1-2 converge posteriorly; (b) arculus proximal to Ax2; (c) 3-5 cells between quadrilateral and subnode [2-5]; (d) Cux stands distal from origin of anal vein by about 3x its own length. However, differs from M. singularis and M. saralisa by (1) less widespread, and ranging from Sudan to Egypt and W Africa; (2)smaller size, Hw 19-21 mm; (3) 13-15 Px in Fw; (4) base of cerci with simple, short and knob-like process, directed downwards and thus not visible in dorsal view; (5) paraprocts triangular, rather than quadrangular in ventral view, with rather straight outer border. [Adapted from Dijkstra & Clausnitzer 2014; this diagnosis not yet verified by author]

Habitat description

Mostly rivers, but also streams and possibly large lakes, in open landscapes. Often with emergent vegetation and probably submerged roots, probably especially faster sections. From 0 to 500 m above sea level, but mostly below 200.

Distribution

confirmed: Benin; Egypt; Ghana; Nigeria; South Sudan; Sudan; NOT confirmed: Ethiopia; Togo


Male (young) © Jean-Pierre Boudot


Appendages (dorsal view)

Appendages (lateral view)

Appendages (ventral view)

Appendages (caudal view)

Map citation: Clausnitzer, V., K.-D.B. Dijkstra, R. Koch, J.-P. Boudot, W.R.T. Darwall, J. Kipping, B. Samraoui, M.J. Samways, J.P. Simaika & F. Suhling, 2012. Focus on African Freshwaters: hotspots of dragonfly diversity and conservation concern. Frontiers in Ecology and the Environment 10: 129-134.


Reference

  • de Sélys-Longchamps, E. (1886). Révision du Synopsis des Agrionines. 1e partie (Légions Pseudostigma, Podagrion, Platycnemis et Protoneura). Memoires couronnes Academie royale Belgique, 38, 1-233

Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. http://addo.adu.org.za/ [2018-09-20].