Rassim Khelifa | Mouloud Mammeri University Algeria (original) (raw)

Papers by Rassim Khelifa

Calopteryx exul is an endemic endangered damselfly that suffers considerable habitat degradation ... more Calopteryx exul is an endemic endangered damselfly that suffers considerable habitat degradation and local extinctions throughout its geographic range. Although recent studies have investigated its distribution, ecology and larval systematics, the life history of the species is still unknown. In this study, a field survey was conducted to determine larval development, temporal pattern of emergence and teneral spatial distribution of the species in the Seybouse watershed, northeast Algeria. Larval growth was investigated in two populations: one at about 200 m (low-elevation population) and the second at 600 m of elevation (high-elevation population). The species showed partial bivoltine life cycle in both low-and high-elevation population. The temporal pattern of emergence of the first flight season of the year at low-elevation population was asynchronous with an emergence season lasting 46 days and half of the population emerging in 15 days. The second flight season was shorter with a most likely smaller population size. Sex ratio at emergence was slightly male biased. After ecdysis, tenerals stayed next to the water within a mean distance of 4.76 AE 4.35 m (AE SD) with no significant difference between sexes. Conservation measures that should be taken into account in the elaboration of future management plans for the species are discussed.

Although the endemic damselfly, Platycnemis subdilatata Selys, 1849, is widespread in the Maghreb... more Although the endemic damselfly, Platycnemis subdilatata Selys, 1849, is widespread in the Maghreb, many aspects of its reproductive behaviour, biology and ecology are still unstudied. One particular feature of this species is that its coloration pattern continues to change during maturation and afterwards, which makes it a good model for assessing age effects on behavioural and biological components. This study aims first to investigate the reproductive behaviour and choice of oviposition site, and second to assess clutch size and egg deposition rate as a function of age in a natural population located in NorthEast Algeria during the reproductive season of 2012. Males seized females next to reproductive sites and in foraging sites. Non-receptive females refused to mate with males by raising their abdomen up while perched or by curving the abdomen up while flying; the angle of abdomen elevation when perched was correlated to male persistence (the number of times that a male tried to grasp the female prothorax while flying over her). Copulation lasted about 14 min, the subsequent oviposition 54 min. Field experiments on oviposition site selection showed that the females prefer to lay eggs in Typha angustifolia leaves. Clutch size and egg deposition rate pattern through age showed an increase in early mature life followed by a decrease later on.

The restoration of endangered relict populations is challenging in conservation biology because t... more The restoration of endangered relict populations is challenging in conservation biology because they require specific environmental conditions within an inhospitable regional climate. Urothemis edwardsii Selys is the most endangered dragonfly in the Mediterranean with only one known relict small population (Lac Bleu) left in Northeast Algeria. With the absence of successful (re-)colonization over the last two decades, the restoration of the species became a top priority. To improve the status of the species in Northeast Algeria, we carried out a reintroduction and translocation scheme during 2011–2015 and assessed the changes in distribution and population size. Our restoration plan led to the emergence of three populations of which one was restored (Lac Noir), one resulted from successful translocation (Lac Tonga Northeast), and one established after successful colonization (Lac Tonga Southwest). In three localities (Lac Noir, Lac Tonga Northeast, and Lac Tonga Southwest), signs of population growth were observed, whereas no significant trend in the source population (Lac Bleu) was detected. A new population (El Graeate) was also recorded in 2015, but its origin is uncertain. Capture-mark-recapture on adults conducted in 2015 in two sites (Lac Bleu and Lac Noir) showed low recapture rates and no sign of dispersal between the two sites. Dispersal capacity of the species and conservation implications of adult distribution are discussed. This study highlights the importance of using biological indicators in selecting host habitats for the restoration of critically threatened populations.

Ecologists who are interested in using Pokémon Go to find new species (see Nature535, 323–324 (20... more Ecologists who are interested in using Pokémon Go to find new species (see Nature535, 323–324 (2016) and F. de Oliveira Roque Nature537, 34; 2016) could also adopt the gameplay concept to set up wildlife-monitoring schemes that are fun for the public.

1. Several species worldwide show rapid range retraction due to habitat degradation, and some of ... more 1. Several species worldwide show rapid range retraction due to habitat degradation, and some of them have restricted distribution and specific resource needs. Such cases deserve particular attention and need urgent conservation actions to avoid extinction, and one way is to facilitate colonisation of new habitats by resource supplementation. 2. Here, we investigate the changes in range distribution, during the last decade (2007–2016), of an endangered endemic damselfly, Calopteryx exul Selys, and assess the importance of its favourite host-plant (Potamogeton nodosus) in colonisation and population dynamics in the last existing population of Algeria. 3. We first used dynamic occupancy models to assess range distribution dynamics and we found that both occupancy and colonisation probabilities of the species were positively dependent on the occurrence of P. nodosus. There was also evidence that extinction probability increased with habitat disturbance but decreased with the occurrence of P. nodosus. Our experimental restoration showed that the augmentation of patches of P. nodosus increased the total number of individuals, the number of reproductive events and philopatry. 4. Our study highlights the importance of insect–plant relationship in the establishment of effective restoration plans because of their implication in colonisation and extinction processes and population dynamics. 5. Since most insect species from different orders and ecosystems are ecologically dependent on plants, our restoration approach may benefit a large range of threatened species and improve their conservation status.

The field of odonatology has developed considerably during the past century. Three figures, namel... more The field of odonatology has developed considerably during the past century. Three figures, namely E. Selys-Longchamps, R.J. Tillyard and P.S. Corbet, have undisputedly founded our current knowledge of odonatology and contributed massively to the understanding of systematics, biology, ecology and behaviour of odonates. The year 2017 will mark the 100th anniversary of Tillyard's The Biology of Dragonflies. We review the book and the author's life and contributions to Australian odonatology. We present an updated history of odonatology and highlight prominent advances in the field. The influence of the book on non-scientists is described. Future research in odonatology on aspects that have not been studied and others that need further investigations are discussed.

Several odonate species are threatened in the Mediterranean basin and some of them show alarming ... more Several odonate species are threatened in the Mediterranean basin and some of them show alarming decreasing trends. The distribution and population estimations provided by the IUCN are based on occasional field sampling or non-rigorous methodologies and could be erroneous and misleading. To obtain reliable estimations of the population size and distribution of three threatened species, Calopteryx exul, Coenagrion mercuriale, and Gomphus lucasii, we first conducted capture-mark-recapture in a natural population during one flight season, and second we carried out intensive sampling of adults, larvae and exuviae in the Seybouse watershed, Northeast Algeria. In addition, a revision of odonate occurrence and distribution in the watershed was done by pooling information collected over six years (2010–2015). Our results show that population estimations of the three species are much higher than what the IUCN presents; that is, 2208 individuals of C. exul (22.08% of the estimated global population), 1765 individuals of C. mercuriale, and 11,204 individuals of Gomphus lucasii (about 4.5 times as large as the estimated global population). Moreover, a total of 42 species were recorded in the study site, of which seven are new. The mean number of localities per species increased by a factor of 2.47, e.g. from six to 12 in C. exul, two to 12 in Coenagrion mercuriale and five to 14 in Gomphus lucasii. Our results suggest that the Seybouse watershed is one of the most important areas in North Africa and the Mediterranean basin for these three threatened species and requires particular attention and an urgent conservation plan to reduce anthropogenic effects and maintain populations.

Sympatric territorial species are subject to interference competition when they share the same re... more Sympatric territorial species are subject to interference competition when they share the same resources. The interaction becomes stronger when the coexisting species share similar traits, which is often the case in congenerics. In this study, we investigated the body size, reproductive behaviour, and microhabitat use of two congeneric dragonflies, Trithemis annulata and T. arteriosa, in Northeast Algeria from September to November 2012 in order to assess the potential factors that allow their coexistence in the same system. Even though T. annulata was larger than T. arteriosa, mistaken recognition was often observed. The behavioural sequence of both species exhibited broadly similar patterns in reproductive behaviour but they differed in mate guarding tactics and male-male interference. Copulation duration was shorter in T. annulata than in T. arteriosa. Oviposition bouts lasted longer in T. arteriosa but dipping was faster in T. annulata. Analysis of microhabitat choice showed

The determination of seasonal regulation is important to understand how species have adapted to t... more The determination of seasonal regulation is important to understand how species have adapted to their local environmental conditions. In this study, we investigate the life history of a North African endemic damselfly, Platycnemis subdilatata, in a northeast Algerian population.We combined field and laboratory investigations to assess the embryonic development, larval growth, emergence pattern and adult flight
season. The embryonic development was direct and asynchronous, with 50% of all eggs hatching after three weeks of egg laying and a hatching period ranging from 13 to 51 days. Hatching success was 48.8%, and the causes of hatching failure were infertility and unhatchability. Larval population structure was quite asynchronous during the winter and less so before emergence. The occurrence of larval diapause is improbable due to the increase of the proportion of the last larval stadium in late winter. Emergence was asynchronous with half of the larval population (EM50) emerging after 44 days within an emergence season of 122 days. Sex ratio at emergence was slightly female biased (50.6%). The flight season lasted 133 days starting from early May. The species reached its sexual maturity after six and seven days of emergence in male and female, respectively. Lifespan was not significantly different between sexes with a mean of 7.75 ± 6.45 days (± SD). Our results suggest that the species is univoltine with a typical summer species life history.

Oviposition in odonate females is usually considered finished when the female leaves the oviposit... more Oviposition in odonate females is usually considered finished when the female leaves the oviposition site. However, considering that many species lay their eggs within a set of bouts it is difficult to distinguish between the end of the oviposition bout and the end of the oviposition episode because the females can change the oviposition site from one bout to another. In this study, post-oviposition drinking is suggested as behavioral indicator not only for the end of an oviposition episode but also for egg depletion in females, as investigated in 11 species (six zygopterans and five anisopterans) from five families. This behavior comprises water intake that the female performs at the end of oviposition by dipping the mouthparts in the water a few times before leaving the oviposition site. The role of downward bending of the abdomen displayed during water intake is also discussed.

Emergence and seasonal regulation of the dragonfly Onychogomphus costae Selys, 1885, were surveye... more Emergence and seasonal regulation of the dragonfly Onychogomphus costae Selys, 1885, were surveyed thoroughly during two consecutive years from two nearby stretches upstream the Seybouse River, northeastern Algeria. The emergence season STARTED in mid-May and lasted 68 and 58 days showing a peak in late May and early June in 2011 and 2012, respectively. During the two years 2011 and 2012, 50% of annual emergence occurred after 25 and 22 days, respectively. Sex ratio was slightly but not significantly male BIASED. Female exuviae were recorded at higher height than males. Height of the exuviae fixation was positively correlated to support height and head width. Percentage mortality at emergence was mainly due to deformity and predation counting from 7.9% to 9.15% of the total emergent population. The species seasonal regulation is inferred and discussed based on the emergence temporal pattern and larval development.

Emergence of Gomphus lucasii Selys, 1849, an unstudied Maghreb endemic, was synchronised by overw... more Emergence of Gomphus lucasii Selys, 1849, an unstudied Maghreb endemic, was synchronised by overwintering in the final stadium in the Seybouse River in northeastern Algeria. Regular collections revealed that half of the annual population
emerged during 10 days, showing a typical ‘spring species’ emergence pattern. Sex ratio was slightly male biased (51%). Males and females did not differ in vertical stratification. Emergence support choice was not random, but rather depended on support height, body size, and daily population density. Mortality was caused mainly
by ants, although deformity of tenerals and bird predation were also important factors. Gomphus lucasii has been assessed as vulnerable (International Union for Conservation of Nature (IUCN) Red List), and the information provided in our study will be helpful in future conservation efforts.

The Algerian Cubtail (Gomphus lucasii Selys) (Odonata: Gomphidae) is a river-dwelling dragonfly a... more The Algerian Cubtail (Gomphus lucasii Selys) (Odonata: Gomphidae) is a river-dwelling dragonfly and one of the least known
gomphid in the Palearctic. A survey of the movement patterns and habitat requirements of adults was conducted in the largest currently
known population, located in the Seybouse River (Northeast Algeria). Daily mark-release-resighting surveys along a 2.5 km
stretch of the watercourse and within plots in terrestrial habitats were carried out; a total of 1,316 individuals were marked. The
resighting rate along the watercourse was 8.13% and did not significantly vary with sex and age. Adult spatial distribution differed according
to sex and age. Mature females were significantly further from the water than males. Mature males were observed not only
along the watercourse but also far from the water, up to 450m where reproductive pairs in copula were recorded. Preferred maturation
and foraging sites were open grasslands and dense wheat fields. Philopatry to reproductive sites had a mean of 1.11%, while
philopatry to emergence site was lower (0.4%) and noted only in males. The mean distance of natal dispersal (from emergence to reproductive
areas) was 596.564.94 m. The mean dispersal distance from one reproductive site to another was 180.976238.54 m.
Both mature males and females preferred fast flowing water, but females were observed to oviposit in relatively small watercourses.

Voltinism is an important life history trait that varies with the environment. In temperate zones... more Voltinism is an important life history trait that varies with the environment. In temperate zones, insect populations take a substantially longer time to reach the adult stage in the northern compared to the southern regions. In this study, emergence pattern and larval growthofthethreatenedzygopteran(Odonata)Coenagrionmercurialewereinvestigatedina populationlocatedinthesouthernlimitofitsdistributionrangeinordertodetermineitslife historystrategiesinahotclimateandcomparethemtothosedisplayedinnorthernpopulations. There was no apparent winter diapause. The species produced two generations in a year, with the first generation emerging in mid spring and the second in late summer. The emergencepatternofthefirstgenerationwastypicalofasummerspeciesandlasted48days. All larvae emerged by the end of May. Due to some environmental perturbations, the emergencepatternofthesecondgenerationwasnotsurveyed,buttherewasevidencethat theemergenceseasonwasshort(21days).Larvalstructurepriortothesecondemergenceof theyearshowedthatonly25%ofthepopulationwasinthefinalinstar,whichexplainsthe shorteremergenceseason.Weassumethatthefirsteggslaidinthespringhatchandgrow rapidlytoreachthefinalinstarinlatesummerasaconsequenceofhighertemperaturesand potentialhighfoodavailability.Therewasasignificantseasonaldeclineinbodysizeinboth malesandfemales.Thesecondgenerationhadasignificantlysmallerbodysize,presumably due to the short growth season and/or higher growth rate.

The Purple Swamphen Porphyrio porphyrio is a common rail that previously was little investigated ... more The Purple Swamphen Porphyrio porphyrio is a common rail that previously was little investigated in North Africa.
From 2011 to 2013, its breeding ecology was studied at two natural wetlands in north-east Algeria, namely Garaet
Hadj Tahar and Garaet Messaoussa. Numbers of Purple Swamphens at both localities peaked in late April and early
May. Egg-laying started in early March, whereas hatching started in late March. Peak egg-laying took place in late
March and early April, and peak hatching from mid-April to early May. There were significant differences in the size
and weight of eggs between years and localities. The mean clutch size was 2.75  0.70 eggs and it was not significantly
different between localities and years. Mean hatching success was 51% and it was positively correlated to
nest depth only at Garaet Hadj Tahar. Most nests were built in dense tufts of Typha angustifolia and Phragmites
australis. The main nesting materials were Phragmites australis and Scirpus maritimus.

Coenagrion mercuriale is a threatened damselfly in most parts of its geographic distribution. It ... more Coenagrion mercuriale is a threatened damselfly in most parts of its geographic distribution. It is listed as endangered in North Africa, where no data on its biology or ecology are available. This study aims to illustrate the reproductive behaviour and habitat preferences of adults in a population located in north-east Algeria, representing the southern limit of the species distribution. After emergence, adults spent 3 to 4 days away from the water to mature. Young mature individuals returned to the stream to mate, sometimes not far from their emergence site. The mean duration of copulation and oviposition were 20.08 ± 8.79 min (± SD) and 52.66 ± 12.17 min (± SD), respectively, separated by a short post-copulatory rest of 4.60 ± 2.02 min (± SD). Copulation duration was positively correlated with male body length while resting duration was positively related to copulation duration. Single males and breeding pairs preferred the same habitats, characterized by relatively dense and high in-channel bank vegetation, and a quite large stream bed, with a substrate which mainly consisted of clay and silt. A comparison of the reproductive behaviour and habitat preferences with a population located in the northern limit of the distribution range is presented and discussed.

Knowledge of both phenology and habitat selection are important assets for conservation and manag... more Knowledge of both phenology and habitat selection are important assets for conservation and management purposes. Generally, aquatic insect species have an optimal season and larval microhabitat in which their survival and reproductive success are high. In odonates, emergence is usually a seasonal-restricted process during which the insect has tofind a good timing and a convenient microhabitat to carry out the final ecdysis out of the water. We investigated temporal emergence pattern and microhabitat choice in Orthetrum cancellatum in northeast Algeria, which represents the southern limit of its distribution range. The emergence season lasted 56 days starting from 30.IV and ended on 25.VI, showing a peak on 19.V. The time by which 50% of the annual population has emerged (EM50) was 20 days and the sex ratio was slightly male-biased, with 51.53%. Final instar larvae chose areas with relatively dense vegetation, and this selection was positively dependent on the mean vegetation height and not on sex or body size. Height selection was positively dependent only on the support height that the larva chose. We suggest that larvae consider both predation risks and mainly local microclimate to select their emergence site.

African Entomology, Sep 2013

African Journal of Ecology, Aug 16, 2013

African Entomology, Sep 2013

African Journal of Ecology, Aug 16, 2013