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Rahmani Khaled

  • Biodiversity Journal, 11 (4): 1021-1030

    Khaled Rahmani, Fatiha Koudache & Farid Bennabi
    Diet study of Atlantic horse mackerel (Trachurus trachurus Linnaeus,1758) (Carangiformes Carangidae) caught in Béni-Saf Bay, Western Mediterranean Sea (Algeria)
    https://doi.org/10.31396/Biodiv.Jour.2020.11.4.1021.1030

    ABSTRACT
    This paper gives a description of the diet of Atlantic horse, Trachurus trachurus (Linnaeus, 1758) (Carangiformes Carangidae) living in the bay of Béni-Saf (North-Western Algeria) between November 2015 and October 2016 by analyzing the contents of the stomachs of 488 specimens divided in three classes according to the length of their body. We used several indices such as the coefficient vacancy (V), the percentage of prey (Cn) and the frequency of occurrence of prey (Fc). Of the total stomachs examined, 135 are empty which corresponds to a vacancy coefficient of 27.66. In total, 3912 preys were counted. They belong to ten major taxonomic groups: Copepoda, Euphausiacea, Amphipoda, Mysidacea, Cumaceae Cephalopods, Echinodermata, Molluscs, phytoplankton and Teleosts). The study of diet of T. trachurus shows that it has a broad food spectrum, and is a carnivorous and voracious species (benthpelagic). We found that the first class prefers Crustaceans, the second favors Euphausiacea, and the third prefers the predation of Teleosts. The diet varies with the size of specimens which is proportional to the size of the prey.

  • Biodiversity Journal, 11 (2): 389-398

    Khaled Rahmani & Fatiha Koudache
    Reproductive biology of horse mackerel, genus Trachurus Rafinesque, 1810 (Perciformes Carangidae), caught in Béni-Saf Bay, W-Mediterranean Sea (Algeria)
    https://doi.org/10.31396/Biodiv.Jour.2020.11.2.389.398

    ABSTRACT
    This paper gives a description of reproduction of the horse mackerel (genus Trachurus Rafinesque, 1810) (Perciformes Carangidae) in the west-south coast of Mediterranean Sea in the Béni-Saf Bay, between November 2015 and October 2016. In total, 488 individual were sampled and 240 (49.18%) were males, 208 (42.62%) were females and 40 (8.20%) were undetermined. Length of individuals varied between 7.1 and 35.5 cm and weight from 5.09 to 343.4 g. This work provides values of sizes at first sexual maturity (TL50), that were estimated for males at 155 mm and females 148.5 mm, respectively. The spawning period extends from January to June and the spawning peak occurs from April to July. The factor of condition (K) increased during the sexual resting phase. This factor is weak during the period of reproduction. Coefficient of condition K seems to follow the same pattern as the GSI with high values recorded in spring (M: 3.50 and F: 4.46), (M: 3.00 and F: 3.49), in summer and (M: 1.67 and F: 2.63) in winter, and the lowest values in autumn (M: 0.54 and F: 0.69). The sex-ratio of Trachurus, per months, by season and by size classes, shows a dominance of males. The difference in percentage increases in favor of the males during the reproduction period, between February and July. This ratio inverts in favor of females during the rest of the year.

  • Biodiversity Journal, 10 (3): 207-212

    Bennabi Farid, Belkhodja Moulay, Boukraa Djamila & Rahmani Khaled
    Effect of salinity on the germination of three varieties of Phaseolus vulgaris L. (Fabales Fabaceae)
    https://doi.org/10.31396/Biodiv.Jour.2019.10.3.207.212

    ABSTRACT
    The present study is carried out to compare tolerance levels towards salinity of three varieties of the plant Phaseolus vulgaris L. (Fabales Fabaceae): Cocorose, Eldjadida and Tadalaghte (a Saharan variety harvested from the area of Béchar in the south of Algeria) during germination. The tolerance levels are estimated by percentage of germinated seeds as well as of the length of roots (in cm), during a period of eight days. Preliminary results show that the germination is maximal in the distilled water and decreases with the increase of the salt concentration of the environment. It is non-existant at 300 meq of NaCl in all the varieties. The increase of the salt concentration delays the germination and reduces percentage of germinated seeds. The response of the seeds of P. vulgaris towards the saline stress varies depending on time and salt concentration. The effect of NaCl on germination varies also depending on the variety. It was found that the variety Tadalaghte shows a good tolerance towards salinity better than Eldjadida and Cocorose. The latter is the most sensitive variety.