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The aim of the present study was to determine the population structure and bioecological characteristics of the portunid crab, Carcinus aestuarii in Çardak Lagoon. In this study, the crabs were sampled by means of fyke-nets at 6 different stations between April 2015 and March 2016. A total of 2458 individuals (686 females, 1755 males, and 17 juveniles) were captured. The average carapace length was measured as 38.85 ± 0.17 mm in females, and 47.65 ± 0.16 mm in males. The highest number of specimens was observed in November with 239 individuals, while the lowest number (125 specimens) was observed in February. The reproductive period in both sexes was between November and February and females with eggs were found in November, February and March. An average number of eggs in a female was 61 390 ± 8.48 and the egg diameter was 345 μm. The female : male ratio was 0.39 : 1. This paper includes the first published data on population structure, growth, and reproduction characteristics of C. aestuarii in a protected lagoon in the Turkish Straits System.

[Philocheras fasciatus (Risso, 1816) is reported for the first time from the Turkish Straits system as a result of recent benthic sampling surveys carried out in the Dardanelles (Kilya inlet). Philocheras fasciatus (Risso, 1816) est reporte pour la premiere fois dans le detroit de Turquie, au cours des recents echantillonnages benthiques effectues dans les Dardanelles (baie de Kilya)., Philocheras fasciatus (Risso, 1816) is reported for the first time from the Turkish Straits system as a result of recent benthic sampling surveys carried out in the Dardanelles (Kilya inlet). Philocheras fasciatus (Risso, 1816) est reporte pour la premiere fois dans le detroit de Turquie, au cours des recents echantillonnages benthiques effectues dans les Dardanelles (baie de Kilya).]

During recent faunistic samplings, a total of 57 species of decapod crustaceans was collected in the coastal waters of the Historical National Park located on the Gallipoli Peninsula (including the northeastern Aegean Sea and Dardanelles). The samples were taken at depths ranging between 10 and 28 m at 10 different stations chosen along the coasts of the peninsula in July, 2005. A total of 1425 individuals belonging to 57 species was identified. The dominance of the species varies in each ecological zone; the caridean, Philocheras trispinosus (Hailstone, 1835) was commonest, with a dominance value of 13.79%. Au cours d'echantillonnages faunistiques recents, des crustaces decapodes ont ete recoltes dans les eaux cotieres du Parc National Historique sur la peninsule de Gallipoli (incluant la mer Egee nord-orientale et les Dardanelles). Les echantillons ont ete preleves a des profondeurs allant de 10 a 28 m, a 10 stations differentes choisies le long des cotes de la peninsule en juillet 2005. Un total de 1425 individus appartenant a 57 especes a ete identifie. L'espece dominante differait suivant la zone ecologique. La crevette Caride, Philocheras trispinosus (Hailstone, 1835) etait l'espece la plus commune au total, avec une valeur de dominance de 13,79%.

[The brachyuran (Decapoda) taxocoenosis of a shallow meadow of Zostera marina was studied in a coastal area of the Sinop Peninsula (southern Black Sea, Turkey). Specimens were collected monthly between February 2002 and January 2003 with a beam trawl at depths of 5-20 m during benthic surveys carried out off the Sinop coast. A total of 3206 individuals belonging to 9 species was collected. The structure of the taxocoenosis along the year is dominated by portunid crabs; among these, Liocarcinus vernalis (Risso, 1816) is the most dominant species (36.87%). The largest Brachyura community in the Zostera marina beds was recorded in the summer months (June and July). La taxocenose de crabes (Decapoda) d'un herbier peu profond a Zostera marina a ete etudiee dans une region cotiere de la peninsule de Sinop (mer Noire meridionale, Turquie). Les specimens ont ete collectees chaque mois, entre fevrier 2002 et janvier 2003 a l'aide d'un chalut a perche a des profondeurs de 5 a 20 m au cours des campagnes benthiques menees au large de la cote de Sinop. Un total de 3206 individus appartenant a 9 especes a ete collecte. La structure de la taxocenose tout au long de l'annee est dominee par les crabes Portunidae; parmi ceux-ci, Liocarcinus vernalis (Risso, 1816) est l'espece dominante (36,87%). La communaute de brachyoures la plus dense dans les lits de Zostera marina a ete observee au cours des mois d'ete (juin et juillet)., The brachyuran (Decapoda) taxocoenosis of a shallow meadow of Zostera marina was studied in a coastal area of the Sinop Peninsula (southern Black Sea, Turkey). Specimens were collected monthly between February 2002 and January 2003 with a beam trawl at depths of 5-20 m during benthic surveys carried out off the Sinop coast. A total of 3206 individuals belonging to 9 species was collected. The structure of the taxocoenosis along the year is dominated by portunid crabs; among these, Liocarcinus vernalis (Risso, 1816) is the most dominant species (36.87%). The largest Brachyura community in the Zostera marina beds was recorded in the summer months (June and July). La taxocenose de crabes (Decapoda) d'un herbier peu profond a Zostera marina a ete etudiee dans une region cotiere de la peninsule de Sinop (mer Noire meridionale, Turquie). Les specimens ont ete collectees chaque mois, entre fevrier 2002 et janvier 2003 a l'aide d'un chalut a perche a des profondeurs de 5 a 20 m au cours des campagnes benthiques menees au large de la cote de Sinop. Un total de 3206 individus appartenant a 9 especes a ete collecte. La structure de la taxocenose tout au long de l'annee est dominee par les crabes Portunidae; parmi ceux-ci, Liocarcinus vernalis (Risso, 1816) est l'espece dominante (36,87%). La communaute de brachyoures la plus dense dans les lits de Zostera marina a ete observee au cours des mois d'ete (juin et juillet).]

The growth parameters, mortality rates, and recruitment pattern of Astacus leptodactylus from an unexploited area in inland waters of the northern Marmara region were investigated based on lengthfrequency data using FISAT software. Specimens were collected during eight scientific samplings carried out between March 2005 and May 2006. The seasonalized Von Bertalanffy growth function was fitted to the length frequency data (n = 2434) with the following parameters: L ∞ = 80.8 mm, K = 0.405 year−1, C = 1, and WP = 0.90. The study of functional regressions permits us to conclude that the growth of this population is allometric. Natural mortality (M) was estimated at 0.578 year−1 and total mortality at 0.589 year−. The longevity of the crayfish was calculated as t max = 7.4 year. The recruitment pattern shows that there is peak recruitment in May and June.We also estimated the potential instantaneous fishing mortality coefficient at F = 1.53-1.63 year−1, the instantaneous total mortality coefficient at Z = 2.11-2.21 year−1, and the exploitation rate E = 0.72-0.73, all through the length-converted catch curve procedure using the length-frequency data of the fyke-nets of 32 mm polyamide (PA) mesh size (stretched mesh). Les parametres de croissance, les taux de mortalite et le modele de recrutement d'Astacus leptodactylus d'une zone non-exploitee des eaux interieures du nord de la region de Marmara ont ete etudies a partir des donnees longueur-frequence en utilisant le logiciel FISAT. Les specimens ont ete collectes au cours de huit campagnes scientifiques d'echantillonnage menees entre mars 2005 et mai 2006. La fonction de croissance de Von Bertalanffy s'ajuste aux donnees de longueur-frequence (n = 2434) avec les parametres suivants: L ∞ = 80,8 mm, K = 0,405 an−1, C = 1, et WP = 0,90. L'etude des regressions fonctionnelles nous permet de conclure que la croissance de cette population est allometrique. La mortalite naturelle (M) a ete estimee a 0,578 an−1 et la mortalite totale a 0,589 an−1. La longevite de l'ecrevisse a ete calculee comme t max = 7,4 ans. Le modele de recrutement montre un pic de recrutement en mai et juin.Nous avons aussi estime le taux potentiel instantane de mortalite par peche a F = 1,53-1,63 an−1, le taux instantane de mortalite totale a Z = 2,11-2,21 an−1, et le taux d'exploitation a E = 0,72-0,73, par la technique de courbes de prises converties en longueur en utilisant les donnees longueur-frequence a partir des verveux de vide de maille polyamide (PA) de 32 mm.

Mortality and yield parameters of the rose shrimp, Parapenaeus longirostris were compared with length frequency data collected from the beam trawl fishery in the Sea of Marmara. Von Bertalanffy parameters were estimated as L ∞ = 16.28 cm and K = 0.490 year−1. The rates of total (Z), natural (M), and fishing (F) mortalitiy were calculated as 2.83, 0.97, and 1.86 for a 32 mm PE (polyethylene) cod end. The Z and F rates for two other cod ends, 32 mm PA (polyamide) and 36 mm PA, were, respectively, 2.13 and 1.16, versus 1.57 and 0.60. A study on the relative yield per recruit shows that maximum yield can be obtained at an exploitation rate (E) of 0.53, 0.52, and 0.45, respectively, for 32 PE, 32 PA, and 36 PA cod ends, whereas the current E values are 0.65, 0.54, and 0.38. Consequently, 32 mm PE and PA cod ends cause overfishing pressure on the stock of P. longirostris. La mortalite et les parametres de production de la crevette rose Parapenaeus longirostris ont ete compares avec les donnees de frequence de longueur obtenues a partir de chalutages dans la mer de Marmara; les parametres de Von Bertalanffy ont ete estimes a L = 16,28 cm et K = 0,490 ans−1. Les taux de mortalite totale (Z), naturelle (M) et par peche (F) ont ete evalues a 2,83, 0,97 et 1,86 pour une maille de 32 mm PE (polyethylene) de la poche. Les taux Z et F pour deux autres poches de 32 mm PA (polyamide) et 36 mm PA, ont ete respectivement, 2,13 et 1,16 versus 1,57 et 0,60. Une etude sur la production relative par recrutement montre que la production maximale peut etre obtenue avec un taux d'exploitation (E) de 0,53, 0,52 et 0,45 respectivement pour 32 PE, 32 PA, et 36 PA poches, alors que les valeurs courantes de E sont 0,65, 0,54 et 0,38. En consequence, 32 mm PE et PA poches causent une pression de sur-peche sur le stock de P. longirostris.

The bathymetric distribution of decapod crustaceans on the continental shelf is analysed, based on data obtained during benthic sampling surveys carried out along the Turkish coasts of the Aegean Sea in July, August, and September 2000. A total of 97 species of Decapoda has been identified from a total of 113 hauls that have been studied. La repartition bathymetrique des crustaces decapodes du talus continental est analysee, a partir des donnees obtenues au cours des campagnes d'echantillonnages benthiques realises le long des cotes de Turquie en mer Egee, en juillet, aout et septembre 2000. Quatre vingt dix sept especes de decapodes au total, ont ete identifies dans les 113 prises etudiees.