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Dive into the research topics where Hakan Ayyildiz is active.

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Featured researches published by Hakan Ayyildiz.


Acta Ichthyologica Et Piscatoria | 2014

Age and growth of Capoeta erhani (Actinopterygii: Cypriniformes: Cyprinidae) from the Menzelet Reservoir, Turkey

Hakan Ayyildiz; Yılmaz Emre; Ozcan Ozen; Abdulkadir Yağcı

Age information is the most important biological variable for estimating growth rates of fishes (Homauni et al. 2011). Determination of the age and growth parameters of fish populations is a very important issue for fisheries management. Fish age is usually estimated using the periodicity of the formation of increments in scales, otoliths, fin rays, and vertebrae (Campana 2001). Otoliths, however, are the structures that are the most preferred by fisheries scientists because of the precision of age estimates (Maceina and Sammons 2006, Čikeš Keč and Zorica 2013). The genus Capoeta Valenciennes, 1842 is distributed in southern China, northern India, Turkmenistan, Lake Aral, the Middle East, and Anatolia. These fishes inhabit gravel and stony zones of fast flowing rivers (Türkmen et al. 2002), but some species may also be found in lakes and springs (Turan et al. 2008). In the inland waters of Turkey there are five species and six subspecies of the genus Capoeta (see Türkmen et al. 2002, Elp and Sen 2009). Capoeta erhani Turan, Kottelat et Ekmekçi, 2008 was described from the Ceyhan River, Turkey (Turan et al. 2008). This species has an economic importance in commercial and recreational fisheries for the local people around the ACTA ICHTHYOLOGICA ET PISCATORIA (2014) 44 (2): 105–110 DOI: 10.3750/AIP2014.44.2.03


Zoology in The Middle East | 2009

First record of Gobius couchi Miller & El-Tawil, 1974 from the Aegean Sea (Pisces: Gobiidae)

Ozcan Ozen; Hakan Ayyildiz; Doğan Tuncay; Murat Bilecenoglu

Gulf Sand Gecko, Stenodactylus khobarensis (Haas, 1957): An individual was found at the fringes of JEO on 26 April 2007, and later on 14 May 2008 two were found in the northern desert near Al-Ratqa Police Station (30°01’N, 47°33’E), sharing their habitat with Stenodactylus slevini Wermuth, 1965, which is abundant there. One was also found at Subiya (29 35’N, 48 07’E) on 30 May 2008, sharing the sandy habitat with the Desert Gecko, Stenodactylus doriae Blanford, 1874. Measurements: snout to vent length 54 mm, tail (tip to vent) 39 mm. It had a distinctly protuberant nostril (Fig. 4, right), postmental scales distinctly enlarged (Fig. 4 left), belly scales larger than dorsal scales, no preanal pores present, rostral scale reaching the nostril but first upper labial not, toes cylindrical in shape and two cloacal tubercle rows present. Its described range is the Arabian Peninsula, along the western and southern coasts of the Arabian Gulf including Bahrain and central Oman (LEVITON et al. 1992), so this record extends its range to the northern part of the Arabian Gulf. It may well occur north to southern Iraq and to southwestern Khuzestan/Ahvaz Province in Iran.


Journal of Aquatic Sciences | 2016

GÖKÇEADA ÇEVRESİNDE ZIPKIN İLE KILIÇ BALIĞI (Xiphias gladius) AVCILIĞININ MEVCUT DURUMU

Aytac Altin; Hakan Ayyildiz; Mustafa Emanet; Cenk Alver; Hasan Basri Ormanci

Bu calismanin ana amaci 2015 yili kilic baligi av sezonunda Gokceada cevresinde zipkinla avcilik yapan teknelerin teknik ozelliklerinin belirlenmesi ve sezon boyunca elde edilen toplam av ile birim av (CPUE) miktarlarinin tespit edilmesidir. Teknelerin teknik ozelliklerinin belirlenmesi icin anket calismasi uygulanmistir. Avlanan balik miktarlari (yakalanan balik sayisi ve agirliklari) ise sezon boyunca kayit altina alinmistir. Kilic baligi av sezonunda boylari 8 m ile 15 m, motor guclerinin ise 75 hp ile 450 hp arasinda degisen 20 balikci teknesi Gokceada limanlarina baglanarak avcilik gerceklestirmislerdir. Kilic baligi avcilik faaliyetlerinin 100 - 1000 m arasindaki derinliklerde ve ozellikle 3 bolgede yapildigi tespit edilmistir. Kilic baligi avciligi yapan teknelerin 2015 av sezonunda ortalama 25 gun denize ciktiklari belirlenmistir. Toplam 463 adet balik yakalanmis olup, tekne basina ortalama CPUE (adet/gun) ise 0,88 olarak hesaplanmistir. Gokceada’da karaya cikarilan balik miktari 11731,83 kg olarak tespit edilmistir. Gerceklestirilen bu avciligin ekonomik degerinin 400162.87 TL oldugu hesaplanmistir. Anahtar Kelimeler: Kilic Baligi , Xiphias gladius, Zipkin, Kuzey Ege Denizi


Ege Journal of Fisheries and Aquatic Sciences | 2016

Gökçeada çevresinde zıpkın ile yakalanan kılıç balıklarının (Xiphias gladius) yaş ve büyüme özellikleri

Cenk Alver; Hakan Ayyildiz; Aytac Altin

Bu calismada Kuzey Ege Denizinde 24 Mart – 15 Haziran 2015 tarihleri arasinda zipkin ile yakalanan ve Gokceada’da karaya cikarilan kilic baligi, Xiphias gladius bireylerinin yas ve buyume ozellikleri belirlenmistir. Alt cene catal boylari (LJFL) 70 ile 174 cm ve agirliklari 4 – 69 kg arasinda olan toplam 300 adet kilic baligi analizlerde kullanilmistir. Boy – agirlik iliskisi W = 5E-06L3,188 (R2 = 0,948) olarak hesaplanmistir. Toplam 83 adet bireyden anal yuzgec isinlari kullanilarak yas tayinleri gerceklestirilmistir. Yapilan yas tayinleri sonucunda, kilic baliklarinin 0 - 5 yas arasinda olduklari ve en fazla bireyin 2 yasinda oldugu tespit edilmistir. Von Bertalanffy buyume denklemi L∞ = 218,3; k = 0,193 ve t0 = -2,1031 olarak hesaplanmistir


Journal of the Marine Biological Association of the United Kingdom | 2015

Daily growth rates and hatch date distributions of common two-banded seabream, Diplodus vulgaris inhabiting the Çanakkale shallow waters of Turkey

Hakan Ayyildiz; Ozcan Ozen; Aytac Altin

Otolith microstructure analysis was used to determine daily age, growth rate and hatching periods of young of the year (YOY) common two-banded seabream, Diplodus vulgaris, collected at two sites by using beach seine from Canakkale shallow waters between January and December 2007. Total length of the YOY D. vulgaris was between 12 and 86 mm and the daily ages ranged between 42 and 313 days. Somatic growth rate estimated by fitting a linear regression to the age–length data set was calculated as 0.273 mm day. According to the length–age regression analysis, maximum daily growth rates were found 0.277 mm day in the lowest sea temperature period and minimum values of 0.274 mm day were observed in the declining sea temperature period. Analysis of covariance indicated that there were no significant differences in the linear growth equations for the two cohorts (F 1⁄4 0.4008, P 1⁄4 0.527). Hatching period of the YOY was estimated to occur between October and March with relatively higher frequency in January. This study has shown that YOY D. vulgaris is a winter spawner in the Canakkale shallow waters.


Ege Journal of Fisheries and Aquatic Sciences | 2015

Age, growth and otolith morphometry of Capoeta angorae (Cyprinidae) collected from Menzelet Reservoir and Fırnız Stream (Turkey).

Yılmaz Emre; Hakan Ayyildiz; Ozcan Ozen; Abdulkadir Yağcı

Menzelet Baraji ve Firniz Cayi’ndan Agustos 2011 ve Kasim 2012 tarihleri arasinda elektro-soker ile yakalanan Capoeta angorae bireylerinin yas, buyume oranlari ve otolit (asteriskus) morfometrik olcumleri belirlenmistir. Toplam boy (L) araligi 7.5 ile 27.0 cm arasinda olan C. angorae bireylerinden elde edilen toplam 175 adet otolit analizlerde kullanilmistir. Toplam erkek : disi orani (E : D = 1.52 : 1.00) erkekler lehine egimlidir. Student’s t-test cinsiyetler arasinda boy farkliliginin istatistiksel olarak onemli oldugunu gostermektedir (P 0.05)


Acta Ichthyologica Et Piscatoria | 2015

FEEDING HABITS OF THE MARBLED GOBY, POMATOSCHISTUS MARMORATUS (ACTINOPTERYGII: PERCIFORMES: GOBIIDAE), IN THE ÇANAKKALE STRAIT, NORTHERN AEGEAN SEA, TURKEY

Aytac Altin; Ozcan Ozen; Hakan Ayyildiz; I. Burak Daban

Pomatoschistus marmoratus (Risso, 1810) is a small demersal fish and one of the dominant species inhabiting shallow waters of the Mediterranean. Information, however, on their feeding habits are still scarce. In this study, the stomach contents of P. marmoratus were investigated in order to determine feeding habits accord - ing to seasons and sizes. The fish were collected monthly from 3 stations between October 2008 and August 2009, using a beach seine, from the shallow waters of the Canakkale Strait, Turkey. A total of 383 P. marmora - tus , ranging from 13 to 69 mm TL, were analysed. The most important prey items in the stomach contents were copepods and amphipods. The numerical abundance of each food item in the stomach contents varied significant - ly with season. The diet of juvenile P. marmoratus consisted mainly of copepods. The occurrence of largest prey items such as amphipods and bivalves appeared relatively higher in adults. However, no significant differences were found between the feeding habits of juveniles and adults .


Journal of Fish Biology | 2010

The diet of Clinitrachus argentatus (Blennioidei: Clinidae) in the northern Aegean and Marmara Seas.

Ozcan Ozen; Aytac Altin; Hakan Ayyildiz

Differences in the diet composition of small (28-42 mm total length, L(T)) and large (43-75 mm L(T)) individuals of the cline Clinitrachus argentatus (Clinidae) were evident. Smaller individuals preyed mainly on copepods, whereas larger individuals ate mainly amphipods, isopods, brachyurans and polychaetes.


Journal of Applied Ichthyology | 2009

Length-weight relationships of 17 less-studied fish species from Çanakkale, Marmara region of Turkey

Ozcan Ozen; Hakan Ayyildiz; Alkan Öztekin; Aytac Altin


Turkish Journal of Zoology | 2015

Feeding habits and diet overlap of juveniles of 2 sparids, Diplodus puntazzo (Walbaum, 1792) and Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817), from the North Aegean Sea of Turkey

Aytac Altin; Ozcan Ozen; Hakan Ayyildiz; Adnan Ayaz

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Aytac Altin

Çanakkale Onsekiz Mart University

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Ozcan Ozen

Çanakkale Onsekiz Mart University

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Adnan Ayaz

Çanakkale Onsekiz Mart University

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Alkan Öztekin

Çanakkale Onsekiz Mart University

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A. Altin

Çanakkale Onsekiz Mart University

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Doğan Tuncay

Adnan Menderes University

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Hasan Basri Ormanci

Çanakkale Onsekiz Mart University

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I. Burak Daban

Çanakkale Onsekiz Mart University

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