The present checklist of the spiders (Araneae) of Algeria is based on literature items published from 1846 to 2022. Altogether 876 species belonging to 51 families are listed. Taxonomic references are mentioned for each species, with indication of synonymous usage or taxa changes. Information about species distribution in the Algerian provinces is also provided, revealing significant disparities in knowledge about each province. Linyphiids present the highest number of known species (155) and the highest endemic richness (54 species). Eight families are represented by a single species. 227 species are known exclusively from Algeria. Moreover, a comparison was executed between the results reported in Algeria and those reported in the neighboring countries (Tunisia, Morocco, and Libya).

The application of geometric morphometry on mosquito wings (Culicidae) is considered a powerful tool for evaluating correlations between the phenotype (e.g., shape) and environmental or genetic variables. However, this has not been used to study the wings of the avian malaria vector, Culiseta longiareolata. Therefore, the goal of this study is to investigate the intra-specific wing variations between male and female Cs. longiareolata populations in different types of larval habitats and climatic conditions in Algeria. A total of 256 Cs. longiareolata mosquito samples were collected from January 2020 to July 2021 in three cities (Annaba, El-Tarf, and Guelma) of northeastern Algeria that have two distinct climatic condition levels (sub-humid and sub-arid) and different types of larval habitats (artificial and natural). Nineteen (19) wing landmarks (LMs) were digitized and analyzed based on geometric morphometry. Our results revealed differences in the wing shape of female and male mosquito populations, indicating sexual dimorphism. Moreover, canonical variance analysis (CVA) showed that factors, such as climatic conditions and type of larval habitats, also affect the wing shape of female and male Cs. longiareolata mosquito populations. Furthermore, the wing shape of male populations was more distinct compared with female populations.

Summary. Assessing temporal changes of the distribution of threatened species is paramount for effective management. Threatened species are sensitive to environmental changes and can be extirpated rapidly due to climatic and anthropogenic effects. Here, we monitor the distribution of the locally critically endangered Urothemis edwardsii in northeastern Algeria where the species has been recovering during the last decade after being restricted to a single locality since the 1990s. During the flight seasons in 2018, 2019, and 2021, we conducted field surveys recording the number of males, females, and breeding pairs across 15 sites in northeast Algeria (El Taref province). We found the species at seven sites; reproduction was confirmed at four. In two of the sites, the species was newly recorded but showed no signs of reproduction. We confirmed the maintenance of the reproductive populations that were recently discovered. While the local conservation status of the species is better than that in the 1990s, there are still different threats that need to be addressed and conservation measures that should be implemented or reinforced to ensure maintenance as well as future expansion of the species.

This work focused on monitoring the reproductive phenology of the chaffinch Fringilla coelebs africana for two successive seasons (2016 and 2017) in the mountains of the El Kala National Park (North East Algeria). We searched for nests in the tree stratum or by direct observation of breeding pairs carrying building materials from mid-March to the end of June and found a total of 34 nests that were measured without affecting the breeding process. The results show that nests were built at an average height of 6.3m from the ground. The laying period was 46 days (Early April to mid-May) and the average laying date was May 2. The mean of clutch size is 3.2 eggs per brood. All the previous traits are similar to those recorded in Europe. The mean hatching success rate was 43.1% and the average breeding success rate was 36.3%. These two values are relatively low compared to those found in European populations.

Spiders, as predatory arthropods, play essential roles in ecosystem equilibrium and serve as bioindicators. To contribute to the understanding of spider diversity in northeast Algeria (Annaba province), a survey of spider fauna was conducted in both forest and urban sites over two consecutive years using the "hand collecting" method. A total of 879 adult spiders (681 females and 198 males) were identified, representing 25 families and 67 species. The Salticid Plexippus paykulli (Audouin, 1826) was the most abundant species, with 127 specimens collected. The most abundant families were Salticidae and Araneidae, with counts of 171 and 139 individuals, respectively. The Shannon-Weaver index varied from 2.17 to 3.68 bits across the different sites, while evenness values ranged from 0.60 to 0.75. This study significantly expanded the known spider species in Annaba province from 96 to 138.