Yazar "Yigin, C. Cigdem" seçeneğine göre listele

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    Age, growth and reproduction of the common stingray, Dasyatis pastinaca from the North Aegean Sea
    (Taylor & Francis As, 2012) Yigin, C. Cigdem; İşmen, Ali
    Age, growth and reproductive parameters of the common stingray, Dasyatis pastinaca, in the North Aegean Sea are reported. Age was estimated by counting the growth rings of thin sections of vertebral centra from 83 fish (83 - 114 cm total length, TL). The relationship between TL and the vertebral centrum ratio (CR) was curvilinear, therefore a quadratic model was preferred to describe between the vertebral centrum growth and body growth. The oldest common stingray were 16 years (females) and 10 years (males), which corresponded to total lengths of 114 and 83 cm, respectively. Estimates of von Bertalanffy growth parameters suggest that males attain a slightly larger asymptotic total length (L-infinity = 188.49 cm) than females (L-infinity = 119.96 cm) and grow more slowly (K = 0.065 year(-1) and 0.086 year(-1), respectively). The size at which 50% (TL50) of males and females were sexually mature at 62.5 cm TL.
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    CARTILAGINOUS FISHES AND FISHERIES IN THE AEGEAN SEA
    (Turkish Marine Research Foundation-Tudav, 2015) Yigin, C. Cigdem; İşmen, Ali; Onal, Umur; Arslan, Mukadder
    [Anstract Not Available]
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    ELASMOBRANCHS OF THE SEA OF MARMARA: CATCH, BIODIVERSITY AND CONSERVATION
    (Turkish Marine Research Foundation-Tudav, 2016) Yigin, C. Cigdem; İşmen, Ali; Onal, Umur; Arslan Ihsanoglu, Mukadder
    [Anstract Not Available]
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    Length-weight relationships for ten shark species from Saros Bay (North Aegean Sea)
    (Wiley, 2009) Ismen, A.; Yigin, C. Cigdem; Altinagac, U.; Ayaz, A.
    P>Length-weight relationships are presented for ten shark species sampled with a commercial trawl vessel at depths ranging from 5 to 500 m between March 2005 and June 2008 in Saros Bay, Turkey. The values of the exponent b of the length-weight relationships ranged from 2.6816 to 3.6060.
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    New unusual associations involving parasitic isopods
    (Brill Academic Publishers, 2006) Ates, A. Suat; Trilles, Jean-Paul; İşmen, Ali; Yigin, C. Cigdem
    [Anstract Not Available]
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    Reproductive biology of Lophius budegassa (Lophiidae) in the North Aegean Sea
    (Soc Francaise D Ichtyologie, 2015) Yigin, C. Cigdem; İşmen, Ali; Arslan, Mukadder
    The reproductive biology of black-bellied anglerfish, Lophius budegassa Spinola, 1807, was described for the first time in the Saros Bay, in the North Aegean Sea, between September 2006 and September 2008. A total of 862 specimens (15.7-107.0 cm) was sampled. Sex-ratio, spawning period and length at first sexual maturity were determined. The F:M sex-ratio was close to 1.5. Using gonadosomatic index and gonadal macroscopic observation, the spawning period was estimated to occur between December and March. Length at first sexual maturity was 42.5 cm for males and 58.8 cm for females.
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    Reproductive Biology of Spiny Dogfish Squalus acanthias, in the North Aegean Sea
    (Central Fisheries Research Inst, 2013) Yigin, C. Cigdem; İşmen, Ali
    A total number of 620 Squalus acanthias was sampled from the bottom trawl catches in the North Aegean Sea, Saros Bay from February 2005 to September 2008. The overall F/M ratio was 1.26:1. Females ranged from 17.1 cm to 117.5 cm in total length (TL) and males from 20.8 cm to 121.6 cm. Females showed positive allometric growth (b>3) while males indicated negative allometric growth (b<3). There were statistically significant differences in the relationship for total mass versus TL, and liver mass versus TL between males and females. The smallest sexually mature female was 54.5 cm in TL, while the smallest sexually mature male was 52 cm in TL. Mean length at 50% maturity was estimated at 56.4 cm for females and 52.8 cm for males. The diameter of the yolky oocytes ranged between 0.5 mm and 46 mm, while the mass ranged between 0.01 and 36.24 g. Hepatosomatic index (HSI) and gonadosomatic index (GSI) significanly increased with size in both males and females. While the ranges of HSI and GSI values for males ranged between 1.93-14.09% and 0.01-34.35%, those for females ranged between 1.63-17.17% and 0.01-96.50%, respectively. HSI reached the highest values in both sub-adult and adult specimens, reflecting the role of the liver in the gonadal production.