Les Monogènes parasites du genre Diplodus dans l'Est du littoral algérien

International audienceThis work is based on the study of the Monogenean parasite community of three species of the Teleostean fish Diplodus Rafinesque, 1810 (Sparidae): Diplodus sargus sargus (Linnaeus, 1758), D. annularis (Linnaeus, 1758) and D. vulgaris (E. Geoffroy St.- Hilaire, 1817) from various localities of the eastern Algerian coastline: the Gulfs of Skikda and Annaba, the coastline of El Kala, and the El Mellah lagoon. Observation of morphological and anatomical criteria of collected Monogeneans from all host species reveals the presence of 11 species, two thirds of which are related to the subclass Monopisthocotylea Odhner, 1912. The results of the distribution of parasitic indices at studied host species show that the prevalence and parasitic load vary from one host species to another and from one site to another. In the lagoon, where the parasite species richness is the lowest, the values of the intensity of infestation and abundance are however the highest. The highest parasitic loads are noted in Diplodus sargus sargus (Linnaeus, 1758) in all localities

Influence of site and host on parasites of two teleost fish in Algeria revealed by using indicator species analysis

International audienceThe indicator value methods are important to conservation biology because it is conceptually straight forward and allows researchers to identify bioindicators for any combination for habitat types or areas of interest. (Mc Geoch & Chown, 1998). The spatial distribution of parasitic copepods from teleost fishes (Chelon labrosus, Mugil cephalus, Liza aurata and Dicentrarchus labrax) was studied in two sites (Annaba gulf and El Mellah lagoon) in the eastern Algeria coastline using indicator species analysis (Indval) to identify parasite species as bioindicators of a given ecosystem during 2005-2008, also identified parasites as bioindicators relative to host. The randomization test identified four parasite species (Caligus mugilis, Ergasilus liza, Lernanthropus mugilis, Caligus minimus) having a significant indicator value for the site and six indicators for the host (Caligus mugilis, Ergasilus bora, Lernanthropus kroyeri, Lernanthropus mugilis, Caligus minimus, Ergasilus liza). Data on species composition and infection levels would help improve the monitoring and management of parasitism in Mugilidae and Moronidae populations. However none pointed out the role of parasitic copepods as bioindicators in Algerian costs

The Copepod parasite of the gills of four teleost fishes caught from the gulf of Annaba (Algeria)

International audienceThe examination of the gills of 960 fishes belonging to four species: Diplodus annularis, Pagellus erythrinus, Lithognatus mormyrus and Mullus barbatus collected from the Gulf of Annaba, enabled us to identify 13 species of parasitic copepods: Caligus ligusticus, Caligus diaphanus, Clavellotis sp, Clavellotis sargi, Clavellotis pagri, Clavellotis strumosa, Lernaeolophus sultanus, Hatschekia pagellibogneravei, Hatschekia sp, Hatschekia mulli, Sparidicola lithognathi, Neobrachiella exigua and Alella macrotrachelus. The distribution of copepods identified, varies from one host species to another and one season to another. P. erythrinus and L. mormyrus present the important number of copepods species. However, the winter presents the highest parasitic diversity (13). Furthermore, the majority of oixenous species are counted. The rates of most values are recorded in summer (33%) and spring (25%). It is also, D. annularis which shelters more of the 2/3 population of copepods collected. The copepod H. pagellibogneravei is the most abundant. The evaluation of parasitic indices shows that, it is during the summer and spring that the maximum values are recorded

Relationships between environmental conditions and phytoplankton in the Mellah lagoon (south western Mediterranean, Algeria), with an emphasis on HAB species

peer reviewedA bi-weekly monitoring of environmental parameters and microphytoplankton assemblages was conducted in the well-preserved Mellah lagoon ecosystem (south western Mediterranean). Sampling was performed at 3 stations in 2016. We aimed to study the evolution of the phytoplankton community with a focus on harmful species in relation with the environmental characteristics. Phytoplankton of Mellah Lagoon was characterized by a mixture of marine, brackish-water and freshwater taxa. In all of the stations, 227 species of phytoplankton were identified (160 diatoms and 53 dinoflagellates). The overall mean phytoplankton abundance was higher at station A (2.24·105 cells l-1, early September) and B (2.98·105 cells l-1, early October) near of marine inputs, compared to station C (1.73·105 cells l-1, early June) located in the south of the lagoon. Diatoms dominated in spring and dinoflagellates developed in summer and early autumn in the Mellah. The dynamic of the phytoplankton in Mellah was influenced by temperature and salinity. For the first time, a number of potentially toxic species have been identified, including 2 diatom species: Pseudo-nitzschia delicatissima-group (max.: 2.52·103 cells l-1), Pseudo-nitzschia seriata-group (max.: 700 cells l-1) and 6 dinoflagellate species: Alexandrium minutum (max.: 1.42·103 cells l-1), Alexandrium tamarense/catenella (max.: 1.35·103 cells l-1), Dinophysis acuminata (max.: 180 cells l-1), Dinophysis sacculus (max.: 120 cells l-1), Akashiwo sanguinea (max.: 7.20·103 cells l-1), Prorocentrum lima (max.: 110 cells l-1). Even the abundances of the HABs species were relatively low in Mellah lagoon, they could potentially form blooms in the coming decades at the favor of warming and trophic status changes observed in Mediterranean marine systems. Monitoring program of HABs species must be established to gain more insight in the development of potentially toxic species and the toxins produce

Relationships between environmental conditions and phytoplankton in the Mellah lagoon (South Western Mediterranean, Algeria), with an emphasis on HABs species

For the first time, a bi-monthly monitoring of environmental parameters (temperature, salinity, nutrients) and phytoplankton assemblages was conducted in the well-preserved Mellah lagoon ecosystem (South Western Mediterranean, Algeria). Sampling was performed at 3 stations in 2016. The objective was to study the evolution of the microphytoplankton community with a focus on HABs species in relation with the environmental characteristics. In total, 227 microphytoplankton species belonging mainly to Diatomophyceae (160 species) and Dinophyceae (53 species), were inventoried in the Mellah lagoon. There was a clear dominance of diatoms (63%), compared to dinoflagellates (37%). Proliferations of some potentially toxic species such as Prorocentrum micans (7 200 cells.l-1) and Gymnodinium sanguineum (6 000 cells.l-1), were observed in summer and autumn respectively. Other HABs species as Alexandrium tamarense/catenella (1 350 cells.l-1) and Alexandrium minutum (1 420 cells.l-1), were present in winter and spring respectively. Temporal differences in the qualitative composition and quantitative phytoplankton communities in the three stations are discussed in relation with environmental variables. Microphytoplankton populations in the Mellah show diversity and equitability indices of 3.04 bits.cell-1 and 0.94 respectively, showing a structured community during winter and spring. The rest of the year is characterized by unstable phytoplankton populations, where only opportunistic species develop

Spécificité des parasites monogènes et phylogénie de leur hôtes dans l’est du littoral algérien

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Spécificité des parasites monogènes et phylogénie de leur hôtes dans l’est du littoral algérien

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L’infestation par les hatshekiidae parasites de treize espèces de poissons téléostéens du littoral est algérien

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L’infestation par les hatshekiidae parasites de treize espèces de poissons téléostéens du littoral est algérien

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Detecting monogenean indicator species from teleost fishes off the eastern Algerian coastline using the IndVal method.

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