Algerian clubtail  (Gomphus lucasii)

Classified as Vulnerable (VU) on the IUCN Red List 2007 (1).

This colourful dragonfly is a typical member of the Gomphidae family, commonly known as ‘clubtail dragonflies' for the enlarged area at the tip of their abdomen. Like many other members of this distinctive family, this species possesses light green to yellow colouration with black stripes, and widely separated eyes (2) (3).

Confined to the Tell Atlas mountain range from West Algeria and Tunisia, although most records in Algeria are very old (1).

Found in and around permanent mountain streams (1).

Odonata species start their life as aquatic larvae, passing through a series of developmental stages or ‘stadia’ and undergoing several moults as they grow. Before the final moult (emergence), metamorphosis occurs in which the larvae transform into the adult form. Adults complete their metamorphosis after emergence and undergo a pre-reproductive phase known as the maturation period, when individuals normally develop their full adult colour (4).

The Algerian clubtail is a close relative of the European and Moroccan Gomphus simillimus and should show a comparable biology, although nothing has been published for this particular species. Eggs should hatch 10 to 15 days after deposition and the larval period should spread over two to three years, passing through 11 to 15 stadia. The larvae hunt hidden within the sand or leaf litter detritus at the surface of the sediments. Emergence is rapid, and the flight period for the Algerian clubtail lasts from March to mid June (2).

Algerian clubtails do not defend territories and are easily observed on the ground, on stones in the middle of streams, or perched in the vegetation. A fairly low aggressiveness is obvious between males. Female Algerian clubtails lay eggs alone, not being guarded by their mate, touching water by the tip of their abdomen during a typical confused flight, so that eggs will detach easily and fall to the bottom of the river, where a mucus envelope fixes them to the substrate (5).

Adult Odonata feed on flying insects and are often generalised, opportunistic feeders, sometimes congregating around abundant prey sources such as swarms of other insects (4).

Stream drying is a major threat to this clubtail species, and has resulted in the local extinction of several populations. The drying up of streams is mainly the result of irrigation and water harnessing for human use, but is also due to increasingly frequent summer droughts. Domestic and agricultural pollution also pose significant threats, and an expanding human population within Algeria and Tunisia is a major concern (1).

There are currently no conservation measures targeting this species (1).

View information on this species at the UNEP World Conservation Monitoring Centre.