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Aphanius fasciatus (Valenciennes, 1821) is a small cyprinodontid fish with external sexual dimorphism. Endemic to the Mediterranean. It is strongly eurythermic and euryhaline. This study concerns morphological differences and genetic structure of this species in North Africa, the most westerly area of its distribution range. A total of 141 individuals were collected using a beach seine from three locations in Algeria: Mellah lagoon (N = 41) and its neighbour Marsh (N = 30), Ayata Lake (N = 29) and one in Tunisia: Bizerte lagoon (N = 41). For morphometric analysis, 13 landmarks were positioned on lateral photographs taken of the fish. Shape information was extracted from the data with a procrustes superimposition and grouped by gender and location. Proteins extracts were obtained from liver and muscle and used for allozymic analysis to determine genetic variations across locations. Seven isoenzymatic systems: MDH (malate dehydrogenase), GOT (Glutamate oxaloacetate transaminase), PGI (phosphoglucose isomerase), PGM (phosphoglucomutase), EST (esterase), IDH (isocitrate dehydrogenase), LDH (lactate dehydrogenase) were revealed using enzyme-speci���c stains. Canonical variate analysis and discriminant function among procruste covariation matrix shows that the shape of the specimen of Ayata Lake is different from those of the three other localities. Ayata Lake fishes have heads shorter than the other populations; their anal fin is smaller and its distance from pelvic fin is more important than observed in other populations. Genetically, Ayata Lake population is distinguished from other localities by the highest values of Fst (fixation index), Ap (private alleles), Ar (Allelic richness). The Jackknife test shows that the PGM system is responsible of this variation. Evolution and adaptation mechanisms of this species according to different habitats are discussed.

The diet of the black scorpionfish Scorpaena porcus (Linnaeus, 1758) of Annaba Gulf (Eastern Algeria) was studied from April 2011 to April 2012. A total of 520 specimens, with a total length between 10.2 and 27.8 cm, were analyzed. Analysis of the digestive contents revealed a dominance of decapods crustaceans (%IRI = 91.2). This species ingested an average of 0.58 prey weighing 0.73 g. For both sexes, arthropods were essential prey (%IRIm = 73.6; %IRIf = 86.9). The diet of large (L) individuals was mainly divided between arthropods (%IRIL = 56.3) and teleosts (%IRIL = 34). Small (S) and medium-sized (M) black scorpionfish mainly focused on arthropods (%IRIS = 98.3; %IRIM = 86.5). The average annual digestive vacuity was of 40.8% and varied significantly according to seasons. There was no significant seasonal change in diet except in the summer.

A total of 756 specimens of Sarpa salpa (L. 1758) caught in the eastern coast of Algeria was used for population dynamics. Fish ranged in size from 68 to 320 mm total length and weighed from 4.2 to 550 g, with a global sex ratio of 1:1.29 in favor of males. The frequency distribution of the sexes was in favor of a protandrous hermaphroditism. The age of the fish was determined by scalimetry. Maximum estimated age was 7 years for females and 5 years for males with dominance of individuals aged 2 and 3 years (73.4%). The Von Bertalanffy growth model is TL = 27.61 × (1 - e-0.41t) for the total population. Growth performance index of Munro & Pauly (1983) is Φ = 2.49. The relationship between Total length and eviscerated weight (EW) was estimated as EW = 1.034 × 10-2 × Lt3.019 for females and EW = 1.789×10-2 × Lt2.839 for males. The natural mortality coefficient (M) estimates was 0.403 year-1 while fishing mortality coefficient (F) was 0.321 year--1 and the exploitation rate E = 0.443. This work is the first to study the age of S. salpa by scalimetry and the only one that addresses the structure and dynamics of this species on the southern shores of the western Mediterranean.

The diet of the striped seabream Lithognathus mormyrus (Linnaeus, 1758) was investigated in the Gulf of Annaba (Eastern coast of Algeria). A total of 522 individuals (8.1 < TL < 35.5 cm, 5.59 < TW < 499.44 g) was examined from January 2007 to December 2009. The relative importance index (% IRI) combining the three main descriptors of the presence of different ingested preys (%F, %N, %W) was used to characterize the relative importance of different food taxa. Feeding strategy and food habits are determinate. Qualitative and quantitative variations in diet were studied according to seasons, size and sex. The average annual digestive vacuity is 19.92%. Differences observed between seasons were not significant (χY = 6.882; p = 0.075). Lithognathus mormyrus is a benthopelagic and carnivorous fish. The main diet items are in order of importance: Mollusca, Chordata, Foraminifera, Annelida, Arthropoda, Echinodermata, Macrophyta and Cnidaria. A total of 7927 preys were identified to a total weight of 91 g, which represents an average number and weight per individual of 19 preys and 0.21 g respectively. Molluscs are the dominant prey whatever the season, size and sex. Despite the dominance of malacological ingested preys, statistical analysis revealed changes in diet between winter and autumn, and between small and large individuals.

Morocco dentex is an important commercial sparid fish on Algerian coasts, where its distribution is irregular. In two sites, Jijel and El Kala areas, located in the northeast of Algeria, 1725 specimens of Dentex maroccanus were caught and examined for diet composition study and trophic level estimation. Their total length (weight) ranged from 10.4 cm (16.05 g) to 26.8 cm (332.47 g). The Relative Importance Index (%IRI) was used to characterize the relative importance of the different food taxa, and their variations in the diet were studied according to season, sex and sexual maturity. Results from both sites were combined for analysis as no difference of vacuity index (VI: χ2 = 0.048, p = 0.82) and diet composition (correlation coefficient of Spearman: rho = 0.82, tobs = 4.61, p < 0.01) was statistically observed between them. The average annual digestive vacuity was 22.85%. It did not vary according to sex and sexual maturity states (χ2(females, males) = 0.04, p = 0.83; χ2(immature, mature) = 0.26, p = 0.6), but differed significantly between seasons. D. maroccanus fed mainly on Pancrustacea (%IRI = 77.26%) and secondarily on Teleostei (%IRI = 21.85%), while Mollusca (%IRI = 0.87%) and Annelida (%IRI = 0.005%) were consumed accidentally. The mean trophic level (TROPH) of D. maroccanus was estimated at 3.91 (SE = 0.67) and varied with season, sex and sexual maturity state. A slightly lower TROPH value was observed in winter compared to the other seasons, while higher TROPH values were recorded in females than in males, and in mature than in immature individuals. According to this study, Morocco dentex is a carnivore with a marked preference for crustaceans and fish.

The aim of this study is to contribute to a better understanding of Tilapia zillii (Cichlidae) biology in the Saharan wetland of Oued Righ (south-eastern Algeria). Eight seasonal sampling campaigns have been conducted between October 2011 and September 2012 for a total of 813 specimens, including 230 males, 329 females and 254 individuals of indeterminate sex. Reproduction of T. zillii was investigated by considering the reproductive cycle, sex distribution and length at first maturity. Seasonal sex distribution was in favour of females during all seasons. The values of the gonadosomatic (GSI) and hepatosomatic (HSI) indexes of females and males indicated a single reproduction period from April to July. The length at first maturity (Lm50) was 9.9 cm for females and 9.7 cm for males. The condition factor K indicated a good condition of the individuals that is reflected by an accumulation of reserves. The age was determined by two methods: the Bhattacharya’s indirect method (1967) and a direct method, which was based on scale reading on 155 individuals with size from 6.4 to 19.9 cm. Monitoring scale marginal elongation over a year identified the formation period of the stop growth ring, which occurs in winter. These data allowed to determine the spawning period and to estimate the ages of T. zillii.

This paper reports additional records of the Indo-Pacific fish Synagrops japonicus (Doderlein, 1884) in Western Mediterranean. Twenty juveniles of this species ranging from 4 to 4.8 cm (TL) were caught in Annaba Bay, Algeria, using beach seine, in Summer of 2011 (9 specimens, 4 ≤ TL ≤ 4.6 cm) and 2012 (11 specimens, 4.2 ≤ TL ≤ 4.8 cm). Some hypotheses on the origin of this unusual presence are discussed., U ovom radu se navode dodatni nalazi vrste Synagrops japonicus (Doderlein, 1884) u zapadnom Mediteranu. Uhvaćeno je dvadeset juvenilnih primjeraka ove vrste u rasponu od 4 do 4,8 cm (TL) u Annaba zaljevu, Alžir, pomoću obalne mreže potegače, u ljeto 2011. godine (9 primjeraka, 4 ≤ TL ≤ 4,6 cm) i 2012. (11 primjeraka, 4.2 ≤ TL ≤ 4,8 cm). U radu su iznesene neke hipoteze o podrijetlu ove neobične prisutnosti.

Otolith shape analyses were conducted on two species of barracudas (Sphyraena sphyraena and Sphyraena viridensis) from the Gulf of Annaba (south-western Mediterranean). The otolith shape was described by elliptic Fourier descriptors from 14 harmonics and by five indices of shape (coefficient of form, roundness, circularity, rectangularity and ellipticity). The comparison through canonical discriminant analyses (CDA) was performed between species and between right and left otoliths. The CDA demonstrated strong discrimination of the two species, with significant differences and a high classification success. The percentage of well-classified individuals in predefined groups was higher than 80%. The combined use of morphometric variables (from indices) and external outlines (shape analysis through Fourier series) demonstrated the importance of otolith shape for interspecific discrimination.

Age, growth and reproduction of 493 jewelfish Hemichromis bimaculatus Gill, 1862 in the valley of Oued Righ (Algeria) were studied from December 2010 to December 2011. The total length and weight of the individuals ranged from 21 to 107 mm and 0.20 to 14.9 g, respectively. Monthly follow-up of the scale marginal growth allowed identifying only one growth stop annulus per year, occurring in April. Back-calculations of total length-at-age permitted to determine that the population was composed of three age classes in both sexes. The adjustment to von Bertalanffy growth model was satisfactory with L∞ = 11.6 cm, K = 0.2, to = -0.5. The fitted total length-total weight relationship was W = 0.026 L2.803. Macroscopic examination of gonads and monthly follow-up of gonadosomatic index indicated that spawning occurred once a year between March and June with a peak activity in April-May. The GSI reached a maximum of 1.12% in males and 7.52% in females. The length at first maturity was 4.5 cm for males and 5.7 cm for females.

L’âge, la croissance et la reproduction du sar tambour, Diplodus cervinus cervinus (Lowe, 1838), ont été étudiés sur les côtes de l’Est de l’Algérie, à partir de 190 spécimens. En utilisant la méthode scalimétrique, nous avons pu identifier 13 groupes d’âge dans la population échantillonnée (9,8 < Lt < 52,7 cm ; 19 < Mt < 2100 g). Les paramètres de la croissance sont Lt∞ = 68,83 cm, K = 0,105 et t0 = –0,747, avec un indice de performance de croissance (φ) de 0,86. La relation liant la masse corporelle éviscérée du poisson à sa longueur totale est We = 0,039 Lt2,74. La période de reproduction s’étend de février à septembre et la première maturité sexuelle intervient à une longueur totale de 25 cm.

Le régime alimentaire du rouget de roche, Mullus surmuletus (L., 1758) des côtes de l’est de l’Algérie a été étudié au cours d’un cycle annuel. L’analyse qualitative et quantitative a été réalisée chez les juvéniles et les adultes et en fonction des différentes saisons d’échantillonnage. Les contenus digestifs de 380 spécimens, de longueur totale comprise entre 12,2 et 28,8 cm et de poids total compris entre 21,5 et 321 g, ont été examinés entre janvier et décembre 2002. Au total, 131 tubes digestifs étaient vides, ce qui correspond à un coefficient de vacuité digestive moyen de 34,47%, sans différences significatives entre les juvéniles et les adultes, et quelles que soient les saisons de capture. Cette espèce omnivore, au spectre alimentaire assez étendu (18 espèces), a un comportement de prédation benthique dans lequel les crustacés constituent les proies préférentielles (pourcentage indiciaire du IRI = 85,19). Les annélides viennent en seconde position (%IRI = 11%), mais sont considérés comme des proies secondaires. La prédominance des crustacés, en particulier des amphipodes, est observée quelle que soit la saison et la taille des poissons. Le calcul du coefficient de corrélation de Spearman sur le rang des différentes proies consommées montre une variation dans la composition du régime alimentaire au printemps (ρ = 0,75 ; p ≤ 0,01) et en automne (ρ = 0,6785 ; p ≤ 0,01).

Le régime alimentaire du bogue Boops boops (L., 1758) du golfe d’Annaba a été étudié entre janvier 2005 et janvier 2006. Les contenus digestifs de 665 spécimens, de longueur totale comprise entre 9,6 et 26,6 cm, ont été analysés en fonction des saisons de prélèvement et du sexe des poissons. Durant toute la période d’échantillonnage, les tubes digestifs étaient pleins, ce qui correspond à un coefficient de vacuité nul. Au total, 1780 proies ont été dénombrées, appartenant à onze phylums différents (Chordata, Cnidaria, Crustacea, Chlorophyta, rhodophyta, Magnoliophyta, Sipuncula, Mollusca, annelida, Protozoa, Nematoda). Boops boops est omnivore et se nourrit de proies benthiques (crustacés, mollusques, annélides, sipunculides, végétaux) et pélagiques (siphonophores, œufs, copépodes). Les algues chlorophycées constituent une part non négligeable dans son alimentation. L’utilisation de l’indice d’aliment principal (MFI) montre qu’aucun aliment ne peut être considéré comme préférentiel ni même principal. L’analyse statistique des contenus digestifs selon le coefficient de rang de Spearman ne révèle des changements significatifs du régime alimentaire qu’en période printanière. Aucune variation de son régime n’est observée en fonction du sexe.

Le régime alimentaire du corb Sciaena umbra (L., 1758) est étudié sur les côtes de l’est de l’Algérie. Un total de 209 individus, de longueur totale comprise entre 17 et 53 cm et de poids total compris entre 48,5 et 2085 g, est examiné entre juin 2001 et mai 2002. Au total, 3416 proies ont été identifiées, pesant 482 g, soit un nombre moyen et un poids moyen de proies par estomac de 17 et 2,5 g respectivement. Les variations du coefficient moyen de vacuité digestive en fonction de la taille des poissons et des saisons mettent en évidence la continuité et l’intensité de l’activité trophique du corb. Ce dernier a un champ de prospection alimentaire assez étendu et un comportement de prédation variée. Toutefois, il se spécialise principalement sur les crustacés. La richesse taxinomique comprend 41 familles, 52 genres et 63 espèces. La faune carcinologique est très diversifiée (20 familles, 31 genres et 43 espèces) et la mieux représentée. L’analyse statistique des variations de l’alimentation en fonction de la taille des poissons et au cours des différentes saisons de capture ne montre pas de différence significative entre les régimes.

Trente-huit espèces de poissons sont présentes dans la lagune du Mellah, dont neuf seulement sont sédentaires. Parmi ces dernières, six sont communes. Les séries statistiques de 1987 à 2003 indiquent une production halieutique annuelle moyenne de 40,3 ± 28,2 tonnes, soit un rendement de 46,5 kg par hectare et par an. L’analyse des captures commerciales montre que les espèces Liza aurata, Chelon labrosus, Mugil cephalus, Sparus aurata et Dicentrarchus labrax sont actuellement les plus abondantes. Leur production est variable au cours de l’année et dépend de l’engin de pêche utilisé. Ce dernier conditionne lui-même la taille des individus capturés.

Le régime alimentaire du sar tambour Diplodus cervinus cervinus (Lowe, 1838) des côtes est de l’Algérie est étudié. Au cours d’un cycle annuel, 144 individus de longueur totale comprise entre 9,8 cm (19 g) et 52,7 cm (2100 g) ont été examinés. Le coefficient de vacuité digestive moyen est de 31,1%. Ses fluctuations mensuelles mettent en évidence un rythme alimentaire saisonnier, caractérisé par un ralentissement de l’activité trophique au printemps. Le sar tambour est omnivore avec un champ de prospection alimentaire pélagique et benthique. Trente cinq taxons entrent dans la composition de son alimentation, dominée par les crustacés caridés et les mollusques bivalves. Aucune proie n’est considérée comme préférentielle, hormis les crustacés qui sont des proies principales, en particulier la petite crevette Alpheus glaber. L’analyse statistique des contenus des tubes digestifs au cours de la croissance des poissons et en fonction des différentes saisons ne montre pas de modification significative de l’alimentation.

Dietary habits and condition of gilt-head sea bream Sparus aurata (Teleostei: Sparidae) in the Mellah lagoon (North-Eastern Algeria). The feeding habits of Sparus aurata in the Mellah lagoon (northeastern Algeria) was studied using three simple methods (frequency of occurrence of prey, numeric percentage and percentage weight) and a feeding coeffi- cient. Monthly variations in the stomach vacuity were also examined. The diet includes a wide variety of food organisms, fish and molluscs bivalvia constituting the favorite preys. A relationship between feeding activity and body condition was observed.

Sexual cycle and fecundity of sea bass Dicentrarchus labrax of Annaba's gulf. Investigations on the reproduction of Dicentrarchus labrax in the gulf of Annaba indicate that the sex-ratio is globally in favor of females (S.R.= 43,0%; P < 0,01) and varies over time and as a function of body length. Examination of monthly evolution of gonado-somatic index, hepato-somatic index and shows adiposity places the reproduction season between December and March and affirms that reproduction involves the mobilisation of energetic reserves contained in the liver and mesentery. The first sexual maturity is more precocious in males (23,5 cm and 2 years old) than in females (30,1 cm and 3 years old), in which the relative fertility is rather low (147 eggs.g-1). A survey of oocyte dynamics shows that there is only a single spawn each year.