Ecological structure of aquatic macroinvertebrate communities in the Hauts Plateaux of Northeast Algeria / Estrutura ecológica das comunidades de macroinvertebrados aquáticos nos Hauts Plateaux do nordeste da Argélia

Aquatic macroinvertebrates are integral parts of functioning wetlands, inhabiting a diversity of aquatic ecosystems where communities are spatially structured. Macroinvertebrates of some Mediterranean regions such as North Africa are still not well studied. Here, we study the community structure of benthic macroinvertebrates in four different types of lotic and lentic wetlands in the semiarid Haut Plateaux of Northeast Algeria. Macroinvertebrates and 06 physicochemical parameters were sampled in 12 sites belonging to four types of habitats (lotic river, lentic river, dams, and sebkha [saline lentic water body]) during January-December 2021. Eventually, the character lentic-lotic was the most important variable affecting the affecting invertebrate communities in the Mediterranean region. The results revealed that sebkha and dams had a lower Shannon index than lentic and lotic rivers. Non-metric multidimensional scaling analysis showed a strong overlap between the community composition in lotic and lentic sites . Howeverin the three types of aquatic groups lentic river, dam and lotic habitats showed a strong overlap between the community whereas sebkha was markedly separated. Redundancy analysis showed that water velocity and pH, were the main drivers of community structure of macroinvertebrates, revealed a strong effect with pH (F1,8=4.15, P = 0.001) and water velocity (F1,8= 3.22, P = 0.002) , separating lotic communities from those that inhabited dams, lentic rivers, and sebkhas. As conclusion, this study contributes to the better understanding of the community structure of macroinvertebrates in semiarid North Africa where wetlands have been experiencing high anthropogenic disturbance.

Macroinvertebrados aquáticos são partes integrantes de zonas úmidas em funcionamento, habitando uma diversidade de ecossistemas aquáticos onde as comunidades são espacialmente estruturadas. Os macroinvertebrados de algumas regiões mediterrâneas, como o norte da África, ainda não foram especificamente analisados. Neste trabalho, almejou-se analisar a estrutura da comunidade de macroinvertebrados bentônicos em 4 tipos diferentes de pântanos lóticos e lênticos no semiárido Haut Plateaux do nordeste da Argélia. Os macroinvertebrados e 6 parâmetros físico-químicos foram amostrados mensalmente em 12 locais pertencentes a 4 categorias de habitats diferentes (rio lótico, rio lêntico, barragens e sebkha - corpo de água salina lêntica) de janeiro a dezembro de 2021. Os resultados revelaram que sebkha e barragens tiveram um pH mais baixo do que os rios lênticos e lóticos. A análise de escala multidimensional não-métrica mostrou uma forte sobreposição entre a composição da comunidade em sítios lóticos e lênticos, mas nos 3 tipos de sítios lênticos, barragem e rio lêntico mostraram uma forte sobreposição, enquanto sebkha foi marcadamente separado. A análise de redundância mostrou que a velocidade da água e o pH foram os principais impulsionadores da estrutura da comunidade de macroinvertebrados, separando as comunidades lóticas daquelas que habitavam barragens, rios lênticos e sebkhas. Assim, à guisa de conclusão, este estudo contribui para a melhor compreensão da estrutura da comunidade de macroinvertebrados no semiárido norte da África, onde as zonas úmidas têm sofrido alta perturbação antrópica.

Water pollution of the Oued D'Hous River (Algeria) and its potential impact on fauna and flora

Water plays a crucial role in all aspects of our lives, including the economy, food security, production, and politics, making it essential for sustainable development. Surface water pollution, which includes rivers, lakes, and oceans, is a significant environmental concern. Oued D'Hous, located in the Wilaya of Bouira in Algeria, is the subject of our research, which examines its hydrochemical pollution resulting from the discharge of domestic, industrial, and agricultural wastewater from the city. The evaluation of the physicochemical parameters reveals that the existing pollutant levels in Oued D'Hous have significantly increased, leading to a high degree of toxicity that threatens the area's flora and fauna. This pollution also limits the use of this resource by humans. We call upon the competent authorities to promptly limit the discharge of these hazardous effluents into Oued D'Hous to prevent further water contamination and reduce the risk of adverse health effects on the public, including those who use the wells located in the vicinity. In conclusion, immediate measures are necessary to mitigate the severe pollution of Oued D'Hous, and we urge the authorities to take action to address this pressing environmental concern.

Molecular diversity and ecogeographic distribution of Algerian wild olives (Olea europaea subsp. europaea var. sylvestris)

Olive is one of the most important crops in the Mediterranean Basin, because of the olive oil economic value and its role in characterization of the rural landscape. The strong influence of climatic changes on the modern agriculture and the availability of a large source of genetic variability pose as crucial future challenges. Therefore, safeguarding olive genetic resources becomes fundamental, not only in cultivated forms in ex situ collections, but also in terms of wild trees in their natural habitat. In this study, 174 samples of oleaster collected in different parts of Algeria were analyzed by 16 nuclear Simple Sequence Repeats (SSRs). The analysis showed a huge genetic variability in the oleaster, and the STRUCTURE and Principal Coordinate Analyses (PCoA) highlighted clusterization of genotypes according to their geographic origin and bioclimatic conditions. Genotypes adapted to harsh climatic conditions were identified, which could be useful to enrich the panel of olive genotypes for breeding purposes and preserve genetic diversity of this species from erosion risks.(AU)

Composition and structure of the skin of dromedary (Camelus dromedarius, L. 1758) young adult from two Algerian populations

In the face of climate change, the eco-dromedary seems to adapt to meteorological constraints. This work compares the skin of the forehead, the hump, and the axillary part of two populations of Algerian dromedaries, namely the Sahraoui and Targui. We worked on six young adult dromedaries of two populations and two sexes genders. We removed the skin from the forehead, the hump, and the axillary part; they were fixed in 10% of formalin. After 48 hours of fixation, the different samples were subjected to different stages of histological techniques. Sections were stained with hematoxylineosin. After mounting the slides, we proceeded to microscopic observations and calculations of each layer of skin thickness. The different skin layers were similar in all body regions dromedaries for the two populations. By comparing the thickness of the skin layers of two sexes and two populations, we notice that the skin from the axillary part of male Sahraoui dromedary is the thickest with the measures 0.0413±0.0222 cm, 0.9789±0.1397 cm, and 2.8119±0.1266 cm for epidermis, dermis, and hypodermis, respectively. The thinnest skin was found in the forehead of the male Targui dromedary with 0.0494±0.0095 cm, 0.2191±0.0536 cm, and 0.3302±0.0835 cm for epidermis, dermis, and hypodermis, respectively. The thickness variation of the skin parts of dromedary between sexes in the same population and between the populations suggests an implication of the adaptation system of dromedary to climatic conditions.

Primary antibiotic resistance and its relationship with cagA and vacA genes in Helicobacter pylori isolates from Algerian patients

The epidemiology of Helicobacter pylori resistance to antibiotics is poorly documented in Africa and especially in Algeria. The aim of our study was to determine the antibiotic resistance rates, as well as its possible relationship with VacA and CagA virulence markers of isolates from Algerian patients. One hundred and fifty one H. pylori isolate were obtained between 2012 and 2015 from 200 patients with upper abdominal pain. Antimicrobial susceptibility testing was performed for amoxicillin, clarithromycin, metronidazole, ciprofloxacin, rifampicin and tetracycline. Molecular identification of H. pylori and the detection of vacA and cagA genes were performed using specific primers. We found that H. pylori was present in 83.5% of collected biopsies, 54.9% of the samples were cagA positive, 49.67% were vacA s1m1, 18.30% were vacA s1m2 and 25.49% were vacA s2m2. Isolates were characterized by no resistance to amoxicillin (0%), tetracycline (0%), rifampicin (0%), a high rate of resistance to metronidazole (61.1%) and a lower rate of resistance to clarithromycin (22.8%) and ciprofloxacin (16.8%). No statically significant relationship was found between vagA and cagA genotypes and antibiotic resistance results (p > 0.5) except for the metronidazole, which had relation with the presence of cagA genotype (p = 0.001).(AU)