Search

One of the economically important species is Penaeus kerathurus (Forskål, 1755), which is widespread in the Mediterranean ecosystem. This paper presents results of research on reproductive biology of Penaeus kerathurus in the Sea of Marmara. A total of 1404 specimens were dissected to determine the maturity stages, reproduction time, and length at first reproduction. The female-to-male ratio was 1:0.9. A high percentage of mature females was determined in April, May and July. Moreover, the value of the gonadosomatic index (GSI) decreased after July. The spawning period was observed between April and July, and its intensity increased in July. The carapace length at first sexual maturity was determined to be 39 mm.

The growth parameters were determined separately for the two sexes of Penaeus kerathurus, as well as for the two (northeastern and southern) substocks of the species in Tunisia. Seasonal sampling from catches of this species in the coastal and the offshore waters was carried out during the period between 2010 and 2012 for the northeastern substock and between 2010 and 2014 for the southern substock in order to collect length frequency distribution data. The modal decomposition of these distributions by the Bhattacharya’s method and refined by the NORMSEP method made it possible to calculate the mean size of each identified mode, which was attributed an age value by referring to the date of spawning and the date of sampling. Based on these data, the L∞ (cm) and K (yr–1) growth parameters for both sexes of the species were calculated using the Von Bertalanffy model. The results showed that females had a higher L∞ value than males, but the growth coefficient K was higher in males than in females for both stocks. Furthermore, the growth parameters in the northeast and in the south of Tunisia were different. A generalized linear model (GLM) test showed that the growth rate, natural mortality, and performance index of Penaeus kerathurus positively correlated to the sea surface temperature.

Penaeus kerathurus is an important species for the fishery, thanks to its high nutritional and economic value. Therefore, this study attempts to determine the length distribution, length-weight relationship, age composition, growth parameters, and mortality rates of a population of P. kerathurus. The material was monthly collected from commercial fishermen in and around Karabiga and the Gulf of Erdek in the Sea of Marmara, between May 2018 and April 2019. The carapace length-weight relationships were calculated as W = 0.0023 × CL2.57, W = 0.0036 × CL2.46, and W = 0.0026 × CL2.56 for the females, males and both sexes combined, respectively. The population studied was distinguished into four age groups, and the tmax (= maximum theoretical age) was found to be reached at 11.9 year. The growth parameters were observed to be = 60.9 mm; K = 0.24 year−1, and t0 = −0.58 year. The rates of total mortality (Z), natural mortality (M), fisheries mortality (F), and exploitation (E) were calculated to be 1.32, 0.43, 0.89, and 0.67, respectively. The results showed that P. kerathurus suffers from a heavy fishing pressure in the sampled area.

Brown shrimp Penaeus aztecus Ives, 1891 seems to be well adapted in the Ionian Sea since its first occurrence in the coastal zone of the island of Corfu during 2013. In the current work, we present additional new records from Argostoli Gulf (Cephalonia Island), Sagiada Bay (Therspotia, NW Greece) and Mesoggi (Corfu Island), which verify the wider distribution of the species. Moreover, direct contacts with shrimpers in the region, suggested that commercial exploitation of the species has been recently established. Although it poses potential threats to the lucrative caramote shrimp (Penaeus kerathurus) populations, which support the income of the fishing communities in the region, the presence of P. aztecus populations represents a new promising fisheries resource.

Bu çalışmada, İskenderun Körfezi’nde Kasım2009-Aralık 2010 tarih aralığında aylık olarak dip trolü çekimlerinden eldeedilen Akdeniz karidesi (Penaeuskerathurus)’nin büyüme parametreleri belirlenmiştir. İncelenen 120 örnek bireyden41 adedi erkek ve 79 adedi dişi olup; erkek/dişi oranı yaklaşık 1/2 dir.Örneklerin total boyları 8.5-19.1cm, total ağırlıkları 4.4-58.41g değerleriarasında değişim göstermekte ve ortalama boy 13.97±2.19cm ile ağırlıkları24.09±11.19g olarak belirlenmiştir. Boy-Ağırlık ilişkisi toplam eşeydeW=0.0108*TL2.8931 (R2=0.9042) olup; büyümede negatifallometrik büyüme özelliği gösterdiği saptanmıştır. Von Bertalanffy Büyümesabitleri L∞=20.95cm, K=0.470yıl-1 ve t0=-0.5138yıl-1olduğu belirlenmiştir. Toplam ölüm oranı (Z), doğal ölüm (M) vebalıkçılık ölüm oranı (F) ile stoktan yararlanma düzeyi (E) sırasıyla 2.45yıl-1,1.09yıl-1, 1.36yıl-1 ve 0.55yıl-1 olaraksaptanmıştır.

The profile and distribution of fatty acids in neutral lipids, phosphatidylethanolamine and phosphatidylcholine of appreciated crustaceans species caught in the Adriatic Sea during the autumn months, namely caramote prawn ( Penaeus kerathurus ), mantis shrimp ( Squilla mantis ) and crab ( Liocarcinus vernalis ), were investigated. The crab’s total fatty acid profile significantly differed from that of caramote prawn and mantis shrimp. Crab was the most valuable dietary source of omega-3 polyunsaturated fatty acids ( n –3 PUFA), with approximately 2-fold higher eicosapentaenoic acid content (131.6 ± 31.6 mg/100 g of edible part) than caramote prawn and mantis shrimp. The caramote prawn presented the highest furan fatty acids (F-acids) level (2.5 ± 0.5 mg/100 g). All crustaceans preferentially accumulated the n –3 PUFA in phosphatidylethanolamine fraction. The F-acid distribution among the lipid classes changed according to the crustacean species. Crab presented F-acids mainly in the neutral lipid whereas caramote prawn contained them predominantly in the phospholipids. On the contrary, F-acids were not detected in the phosphatidylcholine of mantis shrimp. These differences in the distribution suggest different nutritional and health properties given by the consumption of the crustaceans investigated. Moreover, the F-acid profile of the different lipid classes could be used to discriminate these crustaceans.

This work aims to provide deeper knowledge on reproductive biology of P. kerathurus in a multidisciplinary way. Upon 789 examined females, 285 were found inseminated. The logistic equation enabled to estimate the size at first maturity at 30.7 mm CL for female. The Gono-Somatic Index (GSI) showed a pronounced seasonality, ranged from 0.80 ± 0.34 to 11.24 ± 5.72. Histological analysis highlighted five stages of ovarian development. Gonadal fatty acids analysis performed with gas chromatograph evidenced a pronounced seasonal variation; total lipids varied from 1.7% dry weight (dw) in Winter, to 7.2% dw in Summer. For the first time, a chemometric approach (Principal Component Analysis) was applied to relate GSI with total lipid content and fatty acid composition of gonads. The first two components (PC1 and PC2) showed that seasonality explained about 84% of the variability of all data set. In particular, in the period February-May, lipids were characterized by high PUFAs content, that were probably utilized during embryogenesis as energy source and as constituent of the cell membranes. During the summer season, gonads accumulated saturated FAs, that will be used during embryogenesis and early larval stages, while in the cold season total lipids decreased drastically and the gonad reached a quiescent state.

In this study, the flesh yield and proximate contents of caramote prawn, Penaeus kerathurus, were researched depending on sex and seasons. Furthermore, prawns were divided into two groups for freshness assessments at two different times. The first group of prawn was completely wrapped with the stretch film and aluminium foil and stored at room temperature. The second group was placed in water with ice and stored at 4±1 °C (ice storage). The shelf-life of P. kerathurus was determined. Trimethylamine-nitrogen (TMA-N) and pH were analysed to determine biochemical quality and total mesophilic count (TMC) was measured to determine the microbial quality. In addition, sensory analyses were also carried out. The flesh yield of P. kerathurus was on average 52%. It was found that percentages on average moisture, lipid, protein, and ash contents in P. kerathurus were 76.27%, 1.63%, 16.52%, and 1.98%, respectively, and these values changed depending on the season (P

Carotenoids are important antioxidant compounds, present in many foods of plant, animal and marine origin. The aim of the present study was to describe the carotenoid composition of tomato waste, prawn muscle and cephalothorax and avian (duck and goose) egg yolks through the use of a modified gradient elution HPLC method with a C30 reversed-phase column for the efficient separation and analysis of carotenoids and their cis-isomers. Elution time was reduced from 60 to 45 min without affecting the separation efficiency. All-trans lycopene predominated in tomato waste, followed by all-trans-β-carotene, 13-cis-lutein and all-trans lutein, while minor amounts of 9-cis-lutein, 13-cis-β-carotene and 9-cis-β-carotene were also detected. Considering the above findings, tomato waste is confirmed to be an excellent source of recovering carotenoids, especially all-trans lycopene, for commercial use. Xanthophylls were the major carotenoids of avian egg yolks, all-trans lutein and all-trans zeaxanthin in duck and goose egg yolk, respectively. In the Penaeus kerathurus prawn, several carotenoids (zeaxanthin, all-trans-lutein, canthaxanthin, cryptoxanthin, optical and geometrical astaxanthin isomers) were identified in considerable amounts by the same method. A major advantage of this HPLC method was the efficient separation of carotenoids and their cis-isomers, originating from a wide range of matrices.

Benzo(a)pyrene and other 12 polycyclic aromatic hydrocarbons (PAHs) were determined by high performance liquid chromatography (HPLC) with fluorescence detection in different seafoods (Merluccius merluccius, Arnoglossus laterna, Scomber japonicus, Eledone moschata and Penaeus kerathurus) collected along the coast of Napoli gulf (Italy). The results showed that Bap levels exceeded the limit fixed by EU Regulation 1881/2006 in several species and the concentrations of PAHs were higher in winter than in summer season. The presence of carcinogenic PAH in fish is dangerous to human health and should be seriously considered.

The apparent large differences in nutritive requirements reported for different shrimp species precludes extrapolation of available data from one species to another. This fact and the general scarcity of knowledge about crustacean dietary requirements presents a formidable problem to the nutritionist when beginning with a new shrimp candidate. The species used in these experiments was the Penaeus kerathurus, a shrimp native to the eastern Atlantic and Mediterranean coastline. A total of 1,000 postlarvae were used in six experimental trials, concerned with the acceptability of formulated rations and the effectiveness of different protein sources, and considering previous techniques carried out in this field. Other aspects examined were the influence of natural food (mussel mantle and gonad) as a complement to the artificial diet, and the presence in it of an unidentified growth factor(s). From the results obtained, the acceptability of the compounded diets stands out. However, these diets failed to support greater than 50–55% of the fresh mussel diet growth in all experiments. This observation and the strong reduction in nutritional value of the fresh food by processing are related by two possible explanations: first, the rapid leaching of water-soluble nutrients, and second, the idea of a labile unknown metabolite essential for the growth of these animals.

[Methods of length frequency analysis were used to study the growth of the shrimp, Penaeus kerathurus in the Gulf of Gabes. In this area, six trawl surveys were carried out to collect specimens for a series of length frequency distributions. Different techniques (Bhattacharya, Normsep, and Mix) have been used to separate these distributions from their Gaussian component and to determine the average length of the various cohorts. An age was assigned to each mean length (cohort) on the base of previous information regarding the period of spawning and the date of sampling. Growth parameters were calculated using the growth model of Von Bertalanffy (1938) and the data of age and mean length. The mean values of L∞ (mm),K (year), and t0, and their standard deviation (sd) would be for females: 203.43 (sd 15.46), 0.60 (sd 0.16), and −0.88 (sd 0.23), and for males: 157.17 (sd 12.81), 0.78 (sd 0.36), and −1.00 (sd 0.50), respectively. Des methodes d'analyse des distributions des tailles ont ete utilisees pour etudier la croissance de la crevette Penaeus kerathurus dans le golfe de Gabes. Six campagnes de chalutages experimentaux ont ete realisees dans cette region en vue de collecter les distributions de taille des captures de cette espece. La decomposition modale de ces distributions par differentes techniques (Bhattacharya, Normsep et Mix) a permis de calculer la taille moyenne de chaque mode identifie auquel nous avons attribue un âge en nous referant a la date de ponte et a celle de l'echantillonnage. A partir de ces resultats ont ete calcules les parametres de croissance L∞ (mm), K (l'an) et t 0 de l'espece en utilisant le modele de Von Bertalanffy (1938); leurs valeurs moyennes et les ecarts-types (se) correspondants seraient, respectivement, pour les femelles: 203,43 (se 15,46), 0,60 (se 0,16) et −0, 88 (se 0,23); pour les males: 157,17 (se 12,81), 0,78 (se 0.36) et. −1, 00 (se 0,50)., Methods of length frequency analysis were used to study the growth of the shrimp, Penaeus kerathurus in the Gulf of Gabes. In this area, six trawl surveys were carried out to collect specimens for a series of length frequency distributions. Different techniques (Bhattacharya, Normsep, and Mix) have been used to separate these distributions from their Gaussian component and to determine the average length of the various cohorts. An age was assigned to each mean length (cohort) on the base of previous information regarding the period of spawning and the date of sampling. Growth parameters were calculated using the growth model of Von Bertalanffy (1938) and the data of age and mean length. The mean values of L∞ (mm),K (year), and t0, and their standard deviation (sd) would be for females: 203.43 (sd 15.46), 0.60 (sd 0.16), and −0.88 (sd 0.23), and for males: 157.17 (sd 12.81), 0.78 (sd 0.36), and −1.00 (sd 0.50), respectively. Des methodes d'analyse des distributions des tailles ont ete utilisees pour etudier la croissance de la crevette Penaeus kerathurus dans le golfe de Gabes. Six campagnes de chalutages experimentaux ont ete realisees dans cette region en vue de collecter les distributions de taille des captures de cette espece. La decomposition modale de ces distributions par differentes techniques (Bhattacharya, Normsep et Mix) a permis de calculer la taille moyenne de chaque mode identifie auquel nous avons attribue un âge en nous referant a la date de ponte et a celle de l'echantillonnage. A partir de ces resultats ont ete calcules les parametres de croissance L∞ (mm), K (l'an) et t 0 de l'espece en utilisant le modele de Von Bertalanffy (1938); leurs valeurs moyennes et les ecarts-types (se) correspondants seraient, respectivement, pour les femelles: 203,43 (se 15,46), 0,60 (se 0,16) et −0, 88 (se 0,23); pour les males: 157,17 (se 12,81), 0,78 (se 0.36) et. −1, 00 (se 0,50).]

Lower salinity acclimation of hatchery-rear ed Penaeus keruihurus postlarvae was investigated in short and long term experiments at PL20, PL30, PL40 and PL50. In short term experiment, the salinity tolerance was determined with/without acclimation. In tolerance test without acclimation, PLs were transferred suddenly from 36 ppt to 2, 5, 10, 20 and 30 ppt. In tolerance test with acclimation, PLs were acclimated over four days from the reared salinity (36 ppt) to 2, 5, 10 and 20 ppt. After acclimation, PLs were transferred from acclimated salinities to lower and higher salinities. In both tolerance testes, PLs were kept for 96 hr. It was found that acclimation has a significant effect in some cases at PL30 and PL40. In both tolerance tests, the highest salinity tolerance (80-90 % survival rate) was attained at PL50 in salinity range of 10-36 ppt. In long term growth experiment. PLs were reared at 5. 10, 20 and 36 ppt for 30 days using minced clam meat. The highest specific growth rate (SGR), survival and production were recorded at the salinity range.of 10-20 ppt.

13 páginas, 3 figuras, 2 tablas., Ovarian maturation was studied in pond-reared and wild-caught specimens of the shrimp Penaeus kerathurus in order to evaluate the influence of extensive culture conditions on the reproductive capacity of this species. Monthly samples of five female shrimp were taken from the wild and the pond from late winter (February–March) to mid-summer (July). For each specimen sampled, the body length, body weight and ovarian weight were recorded, and the gonadosomatic index (GSI) calculated. Once dissected out and weighed, the ovaries were processed for histological examination. The size reached by the shrimp reared in the pond was comparable to that recorded in the wild. However, significant differences were found in the GSI and the frequency (expressed as percentage) of postvitellogenic (i.e. vitellogenic plus mature) oocytes, which may be considered as good indicators of the sexual maturation rate. On the basis of the overall gonad histology, five distinct stages have been identified throughout the process of ovarian maturation. A major histological anomaly detected in all pond-reared shrimp examined was the absence of fully mature oocytes, which is due to the inability of late vitellogenic oocytes to synthesize cortical rods. Consequently, stage IV ovaries (characterized by the presence of mature oocytes i.e., those bearing cortical rods) were not found in captive animals. As the cortical rods are believed to play an important role at early development in penaeid eggs, their absence is probably one major constraint resulting in a broodstock population with reduced reproductive potential under culture conditions., This work has been supported by grant AGF93-0173 of the CICYT (Comisión Interministerial de Ciencia y Tecnología).

13 páginas, 4 tablas., Lipid class and fatty acid contents, survival and nutritional status of Penaeus kerathurus larvae, reared on a mixture of the marine microalgae Tetraselmis chuii and Isochrysis galbana (clone T-ISO), the rotifer Brachionus plicatilis and Artemia (parthenogenetic strain from Cádiz, S.W. Spain), were studied throughout development. Dry weight and free sterol contents increased and correlated positively (r = 0.91, P < 0.05) during development, whereas the ratio of triacylglycerol/free sterol (an indicator of the nutritional status of the larvae) decreased as did survival. Fatty acid contents at different larval stages reflected fatty acid content of foods. The content of docosahexaenoic acid (22:6n - 3) remained constant during the mysis and first postlarval stage and a low bioconversion rate from its precursor, eicosapentaenoic acid (20:5n - 3) (very abundant in Artemia food) was observed., This work was supported by the Comisión Interministerial de Ciencia y Tecnología, Spain (CICYT projects MAR90-0767-C04-02 and AGF93-0173).

Eight-hundred-and-twenty-five individuals of Penaeus kerathurus were obtained from the landings of shrimp trawlers in a programme from February 1991 to February 1992. These samples consisted of 479 females and 346 males. In each sample the smallest sized specimen was a male and the biggest a female. The mean size Lc (= carapace length) of females (38.8 mm) is significantly greater than the mean size of males (Lc = 32.5 mm). Allometric equations show that the increases in size of, e.g., telson, rostrum, height, total size or weight in relation to the carapace length (reference size) is nearly equal for the two sexes and is expressed for all characters (except height and weight) in both sexes by a negative allometry. Application of the equality test of the regression slope for male and female shows that the parallelism hypothesis is accepted for all the regressions established, except that of weight in relation to the total length where the difference is highly significant.

Unpublished

Unpublished

Size at first maturity and period of egg-laying in Penaeus kerathurus of the Gulf of Gabes, Tunisia, were determined by means of two functional criteria: the presence of spermatophores and the maturation of the ovary. The carapace length corresponding to 50% of the mature females would be in the range of 29 to 30 mm. It is determined by fitting the curve representing the proportion of the females according to the logistic function P = 1 /(1+exp(-a(Lc-Lc50))). The egg-laying period is studied by means of a maturation index (MI = weight of ovary/size). This occurs from June-July to October but the oldest females lay earlier than the youngest.

El informe da cuenta del monitoreo de los principales indicadores biológicos y pesqueros asociados a los crustáceos demersales explotados en la zona marítima centro-norte y centro-sur de Chile. Se analizó información proveniente de bitácoras de pesca recopiladas por observadores científicos a bordo de embarcaciones comerciales, así como de bitácoras de pesca entregadas por los armadores al Servicio Nacional de Pesca, para el año 2009. El área de estudio comprendió desde los 21°26' L.S. hasta 38°28' L.S. Se registró que la flota dedicada a la extracción de los crustáceos demersales estuvo constituida por 21 naves industriales y 5 artesanales The report presentes the monitoring of key indicators related to biological and fishery exploited demersal crustaceans in the sea area north-central and south-central Chile. We analyzed information from logbooks proviniente collected by scientific observers aboard commercial vessels as well as fishing logs submitted by the owners to the National Marine Fisheries Service for the year 2009. The study area included from the 21°26' L.S 38°28' L.S. Joined the fleet for the extraction of demersal crustaceans consisted of 21 industrial units and 5 craft. Unpublished

The reproduction of the karamote shrimp, Melicertus kerathurus (Forskå ; ; l 1775), was studied for the native population in Amvrakikos Gulf (Ionian Sea ; western Greece). Sampling was carried out on a monthly basis between June 1999 and May 2001. The results showed that the shrimp M. kerathurus reproduction period spans between late April and late September. The stimulus for the initiation of the reproduction process was recognised as the rapid increase of water temperature during March. The size-at-maturity was estimated at the size of 45.23 mm carapace length (or 156.2 mm in total length). The smallest mature female in the samples was found 30 mm CL or 113.95 mm TL. Maximum gonad-somatic index was estimated to be 9.62% for female shrimps at stage IV maturity. The population gonad-somatic index peaks in May with an average value of 6.895%. Fecundity was estimated to be 154600 of oocytes per g of gonad tissue at the stage IV (mature female). Monthly sex ratios (males/females) were found higher than 1 throughout the year with maximum values reaching 2.5. A new life cycle pattern is proposed for the particular population.

The reproduction of the karamote prawn, Penaeus (Melicertus) kerathurus (Forskål 1775), was studied for the native population in Amvrakikos Gulf (Ionian Sea; western Greece). Sampling was carried out on a monthly basis between June 1999 and May 2001. The results showed that the shrimp Penaeus (Melicertus) kerathurus reproduction period spans between late April and late September. The size-at-maturity was estimated at a size of 45.23 mm carapace length (or 156.2 mm in total length). The smallest mature female in the samples was found to have 30 mm CL or 113.95 mm TL. Maximum gonadosomatic index (GSI) was estimated to be 9.62% for female shrimps at stage IV gonad maturity stage. The population gonadosomatic index peaks in May with an average value of 6.895%. Potential fecundity was estimated to be 154600 of oocytes per g of gonad tissue at the stage IV (mature female). Monthly sex ratios (males/females) were found greater than 1 throughout the year with maximum values reaching 2.5. A new life cycle pattern is proposed for this particular population., Razmnožavanje kozice, Penaeus (Melicertus) kerathurus (Forskål, 1775), je istraživano na populacijama iz prirodne sredine na području zaljeva Amvrakikos (Jonsko more, zapadna Grčka). Uzorkovanje je obavljeno svakog mjeseca u razdoblju između lipnja 1999. godine i svibnja 2001. godine. Rezultati istraživanja pokazuju da se kozica mrijesti u razdoblju travanj-rujan. Veličina pri kojoj kozica dosiže spolnu zrelost iznosi 45.23 mm dužina karapaksa (156.2 mm ukupna dužina). Utvrđena je najmanja spolno zrela ženka u uzorku pri dužini 30 mm dužina karapaksa (113.95 mm ukupna dužina). Najveća izračunata vrijednost gonadosomatskog indeksa iznosi 9.62% za ženke pri stadiju IV zrelosti gonada. Gonadosomatski indeks za čitavu populaciju ima svoj maksimum u svibnju pri srednjoj vrijednosti od 6.895%. Izračunati potencijalni fekunditet iznosi 154600 oocita po gramu tkiva gonada pri stadiju IV (zrela ženka). Mjesečni omjer spolova (mužjak/ženka) ima vrijednosti veće od 1 tijekom cijele godine uz maksimalnu vrijednost 2.5. Iznesen je i predložak obrasca novog životnog ciklusa populacije na istraživanom području.

Se estudio de contenido en acidos grasos de los lipidos totales, polares y neutros en musculo, hepatopancreas y ovario de hembras de Penaeus kerathurus antes y despues de la puesta. El ovario fue el organo que presento un mayor descenso del contenido lipidico total (50,9%), que se transfirio a los huevos durante la oogenesis. En los diferentes organos estudiados, el contenido de lipidos polares fue superior al de lipidos neutros. Sin embargo, durante la puesta se transfirieron mayores cantidades de lipidos neutros que de polares tanto en el ovario como en el hepatopancreas. El contenido de los acidos grasos saturados de los lipidos totales del ovario disminuyo un 66,3%, el de monoinsaturados un 56,5% y el de los poliinsaturados un 62,6%. Acidos grasos como el 16:0, 16:1 n − 7 y 18:1 n − 9 contribuyeron de una forma importante a la composition lipidica de los huevos. Mientras que el 20:5 n − 3 y el 22:6 n − 3 significaron un 4% y un 4,5% respectivamente de los lipidos totales del ovario que se aportaron a la puesta.

The concentration of TL in Penaeus kerathurus muscle and cephalothorax was 1.03+/-0.04 (75.9+/-0.8% of which was PhL) and 2.36+/-0.07% (45.5+/-0.8% of which was PhL) of the wet tissue, respectively. The phosphatidylethanolamine represented 26.4+/-0.6% (85.6% diacyl- and 14.4% alkyl-acyl- or alkenyl-acyl-analogues) of muscle and 24.7+/-0.2% (90.7% diacyl- and 9.3% alkyl-acyl- or 1-alkenyl-acyl-analogues) of cephalothorax phospholipids while the phosphatidylcholine represented 57.1+/-0.6% (86.9% diacyl- and 13.1% alkyl-acyl- or alkenyl-acyl-analogues) of muscle and 47.2+/-0.4% (89.1% diacyl- and 10.9% alkyl-acyl- or 1-alkenyl-acyl-analogues) of cephalothorax phospholipids, respectively. The main fatty acids of phosphatidylethanolamine were C16:0, C18:0, C18:1 omega-9, C20:4 omega-6, C20:5 omega-3, C22:6 omega-3 and of phosphatidylcholine were C16:0, C18:0, C18:1 omega-9, C20:4 omega-6, C20:5 omega-3. Low percentages of 2-OH C14:0 and cyclo-17:0 fatty acids were also determined. Phosphatidylethanolamine were found to contain a significantly (P0.05) higher percentage of polyunsaturated fatty acids compared to phosphatidylcholine. The omega-3/omega-6 ratio in muscle phosphatidylethanolamine and phosphatidylcholine was significantly (P0.05) higher to the ones of cephalothorax.

El proyecto realiza el monitoreo de los principales indicadores asociados a las pesquerías de crustáceos demersales en la costa d e Chile, caracterizando las especies biológicas y el impacto de éstas pesquerías sobre otras especies The project carries out monitoring of key indicators related to the demersal crustacean fisheries off the coast of Chile, characterizing biological species and the impact of the se fisheries on other species. Unpublished

تـم إعداد قاعدة بيانات شملت خاصة بيانات الأطوال و الثوابت البيولوجية للقمبري الملكي المستغل بمنطقة خليج قابس و ذلك لتحبين تقييم المخزون بواسطة النماذج التحليلية لهذا النوع. و ارتكزت النماذج التحليلية التي اعتمدت في هذه الدراسة على تحليل أجيال الأطوال و إنتاجية الانتدابات. و لقد تم هذا العمل في إطار نشاط مختبر الأحياء البحرية بالمعهد الوطني لعلوم و تكنولوجيا البحار ضمن البرنامج الوطني لتقييم الثروة السمكية. و بينت النتائج ما يلي: - أن مخزون القمبري الملكي في حالة استغلال قريبة من المثلى و أن النفوق الناتج عن الصيد معتدلا و يستهدف القسم البالغ من المخزون. - كل تخفيض في مستوى مجهود الصيد الحالي ينجر عنه نقصان في الإنتاج المستدام للمصايد. بينما تتحمل هذه المصايد زيادة في مجهود الصيد لكن الربحية المستدامة في الإنتاج تبقي ضعيفة. - إن الزيادة في الحجم الأدنى للصيد لا ينجر عنه نقصان في الإنتاج المستدام لكن مخزون الحيوانات البياضة ينمو بصفة ملحوظة. Une base de données, constituée par les paramètres biologiques et les structures en taille des captures (collectées dans le cadre du projet Evaluation des Stocks de Ressources et des Ecosystèmes Benthiques (ESREB) de 2003 à 2005, initié par le Laboratoire des ressources marines vivantes) des deux métiers pêchant la crevette dans le golfe de Gabès, a été préparée de telle façon qu'elle soit accessible par les techniques d'analyse des cohortes sur taille et de rendements par recrue. Selon ces données, les résultats obtenus montrent que : - le stock de crevette Penaeus kerathurus du golfe de Gabès serait dans un état proche de l’exploitation optimale. Les mortalités par pêche sont modérées (valeur moyenne autour de 0.35) et agissent, en grande partie, sur des individus matures. - la diminution de l'effort de pêche actuel entraînerait, à long-terme, une diminution de la production et notamment celle des pêcheurs côtiers. Par contre, l'accroissement de celui-ci entraînerait à terme une amélioration faible des captures de cette espèce. L'augmentation modérée de la taille de première capture (maillage des chalutiers) ne semble pas avoir un effet sensible sur la production globale; quoique l'augmentation du maillage entraînerait des gains durable, légèrement sensible, au niveau de la biomasse féconde. A data base constituted, notably of biological parameters of the species and length distributions (from 2003 to 2005) of the caches of different fleet components exploiting Penaeus. kerathurus is prepared for length cohort analysis and yield per recruit. These data were collected in the Frame of the project “Stock assessment of the benthic resources and ecosystem initiated by life marine resources laboratory. The analysis of this data showed that: - The shrimp stock of P. kerathurus in the gulf of Gabes is in optimum state of exploitation. The fishing mortalities of this stock have a moderate level (mean value around 0.35) and the pattern exploitation is oriented to catch essentially adults. Published

El proyecto realiza el monitoreo de los principales indicadores asociados a las pesquerías de crustáceos demersales en la costa de Chile, caracterizando las especies biológicas y el impacto de éstas pesquerías sobre otras especies. The project carries out monitoring of key indicators related to the demersal crustacean fisheries off the coast of Chile, characterizing biological species and the impact of these fisheries on other species. Unpublished

Bacteriological analysis were carried out to isolate and identify the potential pathogenic species for Penaeus kerathurus post-larvae in microcosm.