Genus Metacnemis Hagen, 1863
blue riverjacks

Type species: Platycnemis valida Hagen in Selys, 1863


The only species, M. valida, is a fairly large (hindwing around 28 mm) damselfly confined to streams and rivers with rocks in the Eastern Cape, South Africa. The genus is the sister-group of Mesocnemis occurring in tropical Africa, differing most notably by the male’s brightly blue-and-black rather than pruinose body. The female is equally robust but coloured dramatically differently, appearing almost uniformly orange brown with cream sides of thorax and abdomen. [Adapted from Dijkstra & Clausnitzer 2014]


For the identification of this genus, please refer to: Tarboton, W. & Tarboton, M. 2015. A guide to the dragonflies (Odonata) of South Africa. Cape Town: Random House Struik.

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.


  • Pinhey, E. (1980). A review of the Metacnemis group (Odonata: Platycnemididae). Arnoldia Zimbabwe 2, 1-13. [PDF file]
  • Samways, M.J., and Tarboton, W. (2006). Rediscovery of Metacnemis angusta (Selys) in the Western Cape, South Africa, with description of male and redescription of female (Zygoptera: Platycnemididae). Odonatologica, 35, 375-378. [PDF file]
  • Ris, F. (1921). The Odonata or Dragonflies of South Africa. Annals South African Museum, XVIII, 245-452. [PDF file]

Citation: Dijkstra, K.-D.B (editor). African Dragonflies and Damselflies Online. [2017-03-01].