L'étude de la reproduction d'Octopus vulgaris a été réalisée au moyen d'un échantillonnage des débarquements des chalutiers côtiers, opérant entre Tan Tan et Boujdour, de décembre 2001 à mai 2003. L'étude montre que la maturité sexuelle est plus précoce chez les mâles que les femelles. Deux périodes de ponte sont mises en évidence par le suivi du RGS : une ponte printanière de mars à juillet, et une ponte automnale, moins intense, se situant entre septembre et octobre. La multiplication des spermatogonies et des spermatocytes atteint son intensité en juillet et décembre, alors que la spermiogenèse est active jusqu'au moment de l'accouplement. La vitellogenèse commence en mi-décembre et s'étend jusqu'à la période de ponte suivante. Le développement gonadique chez les femelles est non synchrone et plus tardif que chez les mâles, soit environ sept mois pour les femelles et trois mois pour les mâles.

The occurrence of a Lessepsian migrant, the Golani round herring, Etrumeus golanii DiBattista, Randall et Bowen, 2012, is reported here for the first time from the Alboran Sea (south-west Mediterranean). On May 2018, twenty individuals were caught by a commercial purse-seiner off Fnideq (Morocco), but five females and two males, were kept by the fisherman for further analyses. This new finding confirms the expansion of this Lessepsian migrant throughout the Mediterranean Sea.

There is a great interest in establishing mussel farming in Dakhla bay. Selection of suitable sites is more meaningful only if a reliable culture method at proposed site is included. We compared two different culture methods, longline and pole, over 1 year (June 2016 to June 2017). Growth indicators for Perna perna (size and weight growth rates, frequency distributions and estimating growth curves) were analysed from seeding to harvest. The results highlighted the influence of culture method on growth rates of mussels (p < 0.05). At harvest, individuals reared on longline presented higher growth rates and consequently reached greater weight and length values than those reared on pole. Mussels reared at the longline grew 73.2 mm and gained 53.5 g W L (live weight) and 3.3 g W t (tissue dry weight) after 12 months of cultivation. However, mussels cultured at the pole gained only 52.3 mm, 26.7 g W L and 1.6 g W t . Aerial exposure of mussels at low tides could explain this reduced performance on pole compared with longline. Size frequency distributions at harvest fitted bimodal distribution in both cultures due to an asymmetric competition among individuals. Effect of density started in both treatments after 7 months of culture when mussels reached 60-70 mm, implying an increment of their food and space requirements. To prevent overcrowding, the initial density should have been reduced through "thinning-out." The longline method exhibited high-performance growth and hence is highly recommended for cultivation of P. perna in Dakhla bay. K E Y W O R D Saerial exposure, crowding conditions, mussel culture, mussel growth, Perna perna, suspended culture, time

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The feasibility of growing red seaweed, Gracilaria gracilis (Gigartinales, Rhodophyta) in off-bottom and floating longline systems was investigated in Bouareg location. The weight gains of G. gracilis in off-bottom cultures tested in winter were low. The lowest daily growth rate (DGR) was recorded in sheet-lines (1.91 % day -1 , p < 0.01) while the highest"s RGR were observed in net-lines and ropes-lines (2.72 and 2.77 % day -1 respectively, p < 0.01). Plants of G. gracilis grew well in the floating longline culture tested at spring. The weight growth rates ranged between 2.54 and 4.26 % day -1 . The highest growth rate in Nador lagoon was observed in treatment stocked with 0.6 kg m -2 . The high stocking density (0.8 kg m -2 ) leaded to low growth most probably due to stress on the seaweed when competing for space and resources. Over a 60-day cycle, the harvest of G. gracilis cultivated on floating longline system in Nador lagoon was estimated at about 101 t FWT ha -1 year -1 . With 8:1 as wet to dry ratio, the production yield per cropping was estimated at 3,156 kg (DW) per ha. However, the total sales per year was estimated at about $ 6,564 per ha.