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Khelifa R.,Faculte Des Science Of La Nature Et Of La Vie Et Des Science Of La Terre Et Of Lunivers
Revue d'Ecologie (La Terre et la Vie) | Year: 2013

Calopteryx exul Selys, 1853 is an endangered endemic Odonata species restricted to the Maghreb that shows an increasing concern about its conservation status, due to substantial habitat loss. A study dealing with its flight period, the apparent sex-ratio of imagoes and adult habitat preferences was carried out in the Seybouse basin, northeastern Algeria, during two years. The flight period of the species begun on early May and ended on late July, showing a peak around late May / early June. Either a small second generation or delayed emergences was responsible of the record of scarce tenerals and immatures in early September. Additional larval investigations are needed to elucidate the origin of such late emergences. The maturation period was estimated to extend over 11-12 days. The apparent daily sex-ratio in the adult population present on site was mostly biased with 65 to 67% of females. Additional work addressing sex-ratio at emergence is needed to understand this disequilibrium. Multivariate analysis showed that adults of C. exul prefer relatively fast flowing shallow water when compared to its congeneric C. haemorrhoidalis (Vander Linden, 1825), which was mainly observed at deeper, slower and very shaded running waters with dense banks vegetation. The population of C. exul dealt with in this study is currently the largest one reported so far in the Maghreb. Data on adult phenology and habitat preferences will allow future investigations about the present distribution of the species in Algeria and the whole Maghreb. Source


Khelifa R.,Faculte Des Science Of La Nature Et Of La Vie Et Des Science Of La Terre Et Of Lunivers
International Journal of Odonatology | Year: 2012

The last instar larva of Calopteryx exul Sélys is described and illustrated based on larvae collected from the Seybouse River (northeast Algeria) and reared in the laboratory. A comparative analysis of three other congeneric species is presented. © 2012 Worldwide Dragonfly Association. Source


Khelifa R.,Faculte Des Science Of La Nature Et Of La Vie Et Des Science Of La Terre Et Of Lunivers | Zebsa R.,Faculte Des Science Of La Nature Et Of La Vie Et Des Science Of La Terre Et Of Lunivers | Kahalerras A.,Faculte Des Science Of La Nature Et Of La Vie Et Des Science Of La Terre Et Of Lunivers | Mahdjoub H.,Faculte Des Science Of La Nature Et Of La Vie Et Des Science Of La Terre Et Of Lunivers
International Journal of Odonatology | Year: 2012

Clutch size is an important fitness component often quantified artificially by inducing oviposition in libel-lulid females. Female behavior and egg production of the yellow-veined skimmer, Orthetrum nitidinerve, were studied in northeastAlgeria during its reproductive season. Dataonreproductive behavior and biology of this Mediterranean endemic species has not been published previously. Males guarded territories within the wetland while females came only to lay their eggs and then went back to terrestrial habitat. In this study we induced oviposition, which depletes all the female eggs, to obtain estimations of egg deposition rate and subsequently clutch size. On average an induced clutch was ca. 2200 eggs while a natural one was about 970 eggs. Artificial clutches were positively correlated to body length but negatively related to mature lifespan. The rate of egg deposition was higher in the afternoon than in the morning, probably because of differences in temperature. During their mature lifespan females oviposited between one and three artificial clutches. © 2012 Worldwide Dragonfly Association. Source

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