Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Plantago coronopus in Northwestern Algerian coast

Mycorrhizal fungi play a major role in the functioning of ecosystems. However, their identification has remained a challenge for scientific research. This study presents the first identification report of species of arbuscular mycorrhizal fungi in the rhizosphere of the halophyte Plantago coronopus L. in Algeria. Samples of rhizospheric soil were collected in spring 2018 at three sites in the Bomo-plage dunes west of Oran, Algeria. The spores were isolated by wet sieving, morphologically identified, and quantified. The mean spore density was 107.94 spores 100 g-1 dry soil, which is high compared to other dune ecosystems. Endomycorrhizal spore morphotypes were involved in the following Genus: Glomus, Septoglomus, Rhizophagus, Diversispora, Funneliformis, Dentiscutata, Claroideoglomus, Scutellospora, and Entrophospora, to the following Family: Glomeraceae, Gigasporaceae, Diversisporaceae, Claroideoglomeraceae, and Acaulosporaceae. The Glomeraceae was the most dominant identified family. The identification of indigenous arbuscular mycorrhizal fungi has been shown to be essential for future programs to restore disturbed dune ecosystems.

First data on cetacean strandings and in situ observations along the Algerian coast

Data on cetaceans within the pelagic ecosystem remains scarce in the Algerian basin. This is linked to a lack of investigations stemming from the difficulty of quantitative population evaluation through oceanographic surveys and/or strandings statistics. In this context, we considered that it is appropriate to focus on data acquisition from offshore observations as well as setting up a network for monitoring strandings on sites scattered along the Algerian coast. During 10 oceanographic surveys conducted in two Algerian coasts sectors (eastern and central) we observed a total of 245 delphinids corresponding to 8 species that had an irregular distribution. We also identified 83 individuals belonging to five species that stranded between 2007 and 2017.

Multiple records and polymorphism of Parastichopus regalis (Cuvier, 1817) (Echinodermata: Holothuroidea: Stichopodidae) along the Algerian coast

The family Stichopodidae is represented in the Mediterranean Sea by the genus Parastichopus which includes two non-endemic species; Parastichopus tremulus (Gunnerus, 1767) and Parastichopus regalis (Cuvier, 1817). On the Algerian coast (southwestern Mediterranean Sea), two morphotypes of P. regalis were observed, one with dark spots on the dorsal surface and the other non-spotted. In total, 65 individuals of P. regalis were recorded from 22 stations along the Algerian coast during an oceanographic campaign. Twelve individuals (6 of each morphotype) were used for a comparative study of the morphological (including endoskeletal) characteristics. Table ossicles, the only ossicles of the body wall of the two morphotypes of P. regalis, are here compared with regard to the disk diameter of the tables and the total area of the surface of the disc. Statistical analysis did not show any significant differences between the spotted and the non-spotted morphotypes.

On the taxonomic status of Holothuria (Holothuria) tubulosa (s.s.) from the Algerian coast with the description of a new Mediterranean species, Holothuria (Holothuria) algeriensis n. sp. (Echinodermata: Holothuroidea: Holothuriidae)

In this study we redescribe the taxonomy of some holothuriid species collected from different localities of the Algerian coastal waters. Morphological (anatomical and endoskeletal) and previous molecular studies show the presence of two distinct morphotypes of Holothuria (Holothuria) tubulosa “A” & “B”. Morphotype “A” corresponds to the classical Holothuria (Holothuria) tubulosa Gmelin 1791, described by Koehler (1921) and hereafter referred to as H. (H.) tubulosa (s.s.), while morphotype “B”, we believe, represents a new species, herein named H. (Holothuria) algeriensis n. sp. with characteristics significantly different from those of Holothuria (H.) tubulosa (s.s.). Both morphology and statistical analysis (Linear Discriminant Analysis) confirm significant differences between these two morphotypes. To visualize these differences, measurements made on ossicles of Holothuria (H.) tubulosa (s.s.) and Holothuria (H.) algeriensis n. sp. were compared with other species present in our collections, including the north-eastern Atlantic and Mediterranean Holothuria (Roweothuria) arguinensis Koehler & Vaney, 1906, recently recorded from Algerian waters, the Mediterranean Holothuria (Roweothuria) poli Delle Chiaje, 1824 and Holothuria (Holothuria) stellati Delle Chiaje, 1824. We conclude that the two morphotypes of H. (H.) tubulosa are significantly different to warrant the recognition of a new species, H. (H.) algeriensis n. sp. and the linear discriminant analysis (LDA) of the five species demonstrate this.

Directional Bilateral Asymmetry in Fish Otolith: A Potential Tool to Evaluate Stock Boundaries?

The otolith, found in both inner ears of bony fish, has mainly been used to estimate fish age. Another application that has been developing significantly in recent years, however, is the use of otolith shape as a tool for stock identification. Often, studies have directly used the shape asymmetry between the right and left otoliths. We tested the magnitude of directional asymmetry between the sagittal otoliths (left vs. right) of 2991 individuals according to their catch locations, and we selected species to evaluate whether directional asymmetry may itself be a tool to evaluate stock boundaries. Elliptical Fourier descriptors were used to describe the otolith shape. We used a flatfish, the common sole (Solea solea, n = 2431), from the eastern English Channel and the southern North Sea as well as a roundfish, the bogue (Boops boops, n = 560), from the Mediterranean Sea. Both species showed significant levels of directional asymmetry between the testing locations. The bogue otoliths showed significant asymmetry for only 5 out of 11 locations, with substantial separation between two large areas: the Algerian coast and the western part of the Italian coast. The sole otoliths showed significant asymmetry in the shape analysis (3.84%–6.57%), suggesting a substantial separation between two large areas: the English and French parts of the English Channel and the southern North Sea. Consequently, directional bilateral asymmetry in otolith shape is a potential new method for stock identification.