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    Abnormalities in the amphids of free-living nematodes in the black sea: Is it atavism or result of a modern morpho-functional adaptation to environmental changes and the nascent process of microevolution?
    (Nova Science Publishers, Inc., 2016) Sergeeva, Nelli G.; Ürkmez, Derya; Revkova, Tatiana N.
    In this chapter we aim to summarize our long-term data (1988-2015) about the abnormalities detected in the development of the vital chemoreceptor organs (amphids) of 49 nematode species from the Black Sea. The total list of species includes 28 valid species and 21 morphotypes, systematic position of which have been identified only to genus level as well as individuals close to a valid species (cf.), however, they require further study and clarification in our view. Amphid abnormalities are characterized by a wide spectrum of appearances. Accordingly, they may have a non-standard number of elements of a species-specific form (instead of two elements they may have 1 or 3-5); one element of amphid may be underdeveloped or not have a speciesspecific form; the topography of amphids in relation to the front edge of the head and to the axis symmetry of the body may be disturbed. Anthropogenic impact on the Black Sea ecosystem is steadily increasing. Its negative effect is revealed in the extinction of species, community perturbations, serious physiological changes in organisms, resulting in different pathological phenomena. It is obvious that the occurrence of specific abnormalities in the vital organs of the same nematodes species is a result of chromosomal mutagenesis. Repeatability and the wide distribution of species with these types of abnormalities in different regions of the basin are shown in this chapter. The issues indicated in this chapter require future research: 1. what is the specific cause of the amphid abnormalities in nematodes? 2. Are these amphid abnormalities offer an advantage or a disadvantage compared to the “normal” organs for organisms inhabiting polluted ecosystems or a life under the impact of climate change? 3. Why similar morphological abnormalities are not recorded in nematodes from the other seas? Are these chemoreceptor organ abnormalities in nematodes unique for the Black Sea? 4. Is this phenomenon shows the nascent process of microevolution of nematode fauna in the Black Sea?. © 2016 Nova Science Publishers, Inc.
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    Current views on the diversity and distribution of deep-water meiobenthos at the Turkish shelf (Black Sea)
    (Centre for Biodiversity of Montenegro, 2017) Sergeeva, Nelli G.; Ürkmez, Derya
    Deep-water meiobenthos of Turkish shelf has been evaluated at the Black Sea exit of Istanbul Strait (Bosphorus) and off Sinop peninsula as a result of three scientific cruises. Taxonomic diversity of meiobenthos communities was studied at the Black Sea exit of Bosphorus on a transect with a depth range of 75-300 m. The bottom sediments were collected at the area during two cruises, on board RV "Arar'' (of Turkey) and ''Maria S. Merian" (of Germany) in November 2009 and April 2010, respectively. Data on meiobenthos inhabiting both normoxic and extreme conditions was collected in the studied area and meiobenthos composition included 26 high level taxa. In addition, 2-3 morphotypes of benthic fauna were recorded as incertae sedis, which require further study. The number of higher taxa decreased from 22 to 14-8 when switching from oxygenic conditions (50-125 m) to the anoxic hydrogen sulphide environment (226-300 m). The constant components of meiobenthos included protists (Ciliophora, Gromiidea and soft-shelled Foraminifera), and metazoans were constantly represented by Nematoda and Harpacticoida. In 2011, a quantitative study on meiobenthic composition of the oxic/anoxic interface at the western part off Sinop Peninsula (Southern Black Sea) has also been investigated. The material was collected by ROVs during the expedition (Black Sea Leg) of the exploration vessel (E/V) Nautilus. Results showed that the taxa composition of meiobenthos ranged from 4 to 10 major groups. Free-living marine nematodes were numerically the dominant taxon at each station. Total abundances decreased in parallel to increasing water depth, hence decreasing oxygen levels.
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    Echinoderes dujardinii Claparède, 1863 (Kinorhyncha, Cyclorhagida): A new record for the kinorhynch fauna of Turkey
    (Centre for Biodiversity of Montenegro, 2016) Ürkmez, Derya; Pardos, Fernando; Sezgin, Murat; Karaçuha, Melek Ersoy; Öksüz, Ibrahim
    Meiobenthic samplings conducted in the framework of a meiobenthos project in the subtidal coastal waters of Sinop Bay, Southern Black Sea revealed the first report of the kinorhynch Echinoderes dujardinii for the marine fauna of Turkey.
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    Kırım (Ukrayna) ve Sinop (Türkiye) kıyıları meiobentik kommunite yapılarının Türkiye'nin Karadeniz kıyıları deniz koruma alanlarının (DKA) belirlenmesi kapsamında karşılaştırmalı araştırılması
    (2011) Sezgin, Murat; Dağlı, Ertan; Eyüboğlu, Bora; Şahin, Fatih; Bakır, Kerem; Ürkmez, Derya; Çulha, Mehmet
    [No abstract available]
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    MACROBENTHIC NEMATODES INHABITING MUSSEL BEDS: SEASONAL VARIABILITY IN THE POPULATION STRUCTURE OF ENOPLUS QUADRIDENTATUS BERLIN, 1853 AROUND SINOP PENINSULA (SOUTHERN BLACK SEA)
    (2017) Ürkmez, Derya
    Spatio-temporal distribution and population structure of Enoplus quadridentatus Berlin, 1853 associated with mussel beds were investigated seasonally (October 2013, January 2014, May 2014 and July 2014) along the coasts of Sinop Peninsula, the northernmost point of Turkey located at the Black Sea. A 20x20 cm quadrat was used by scuba divers to collect samples at five stations, of which four of them were located on rocky substrata and one on a concrete pier pile. Nematode densities ranged between 0 – 996 ind.m-2 and found high in October and May. A total of 1100 individuals and 9 species belonging to 8 families were recruited. E. quadridentatus Berlin, 1853 was the dominant species in most of the nematode assemblages inhabiting mussel beds and had a contribution of 74% to the total fauna. The density of the species varied among the seasons with peaks in May and October, consistent with the general nematode densities. Population composition revealed seasonal changes. In general, females were dominant in the population and ovigerous females were recorded only in January and May. Juveniles were found during all seasons, but formed dense populations in July and May. It seems that the reproduction of the species is continuous throughout the year
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    Significant occurrence of Musellifer profundus Vivier, 1974 (Gastrotricha, Chaetonotida) in the Black Sea
    (Pensoft Publishers, 2019) Sergeeva, Nelli G.; Ürkmez, Derya; Todaro, M. Antonio
    Specimens of the gastrotrich genus Musellifer are recorded for the first time from the Black Sea. These specimens, identified as M. profundus Vivier, 1974, were found in sediment samples collected at various depths (22-135 m) and from waters characterized by low salinity (17.3-18.62‰) and varying levels of oxygen (2.43-299.59 µM). Three specimens were found from the Istanbul Strait (Bosphorus) outlet area of the Black Sea (Turkey) and 2 were found along the southern and southeastern shelf of the Crimean Peninsula (Russia), from the Yalta Gulf and the Feodosiya Gulf. © Sergeeva et al.
  • Küçük Resim
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    Sinop City Fishery of the Black Sea
    (Marine Science, 2013) Bat, Levent; Sezgin, Murat; Şahin, Fatih; Özdemir, Zekiye Birinci; Ürkmez, Derya
    The Black Sea has historically been one of the most biologically productive regions in the world. Although it has 168 fish species, there are only a few species of commercial importance and the supply of fishes is limited, because intensive fishing, industrialisation and urbanisation have caused the most favoured species to decline. This review prepared to give information on Sinop fisheries of Turkish coasts of the Black Sea.
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    Sinop körfezi meiobentik nematoda faunasının dinamiği ve Chromadoridae'nin taksonomik ve ekolojik özellikleri
    (Sinop Üniversitesi, 2015) Ürkmez, Derya; Sezgin, Murat
    Sinop Körfezi'nde dağılım gösteren meiobentik nematodların dinamiğini tespit etmek ve Chromadoridae üyelerinin taksonomik ve ekolojik özelliklerini belirlemek amacıyla Ağustos 2009-Temmuz 2010 tarihleri arasında bir çalışma gerçekleştirilmiştir. Bu çalışma kapsamında, araştırma bölgesinden seçilen 4 hat üzerinde yer alan yumuşak substratum özellikli 8 istasyonda 3 tekrarlı olarak 12 aylık bir arazi çalışması gerçekleştirilmiştir. Laboratuvar çalışmaları sonucunda Sinop Körfezi'nde meiobentik komunitenin 25 yüksek taksondan meydana geldiği tespit edilmiştir. Toplam meiobentos içerisinde abundansı en yüksek grup Nematoda olmuştur. Nematoda'nın sığ istasyonlar (3m derinlikteki istasyonlar) A1, B1 ve C1 de toplam meiobentosa yaptığı katkının diğerlerine göre yüksek olduğu görülmüştür. Nematoda Mayıs ayında A1 istasyonunda meiobentosa hem %80e yakın büyük bir katkı sağlamış hem de tüm aylar ve istasyonlar içinde en yüksek abundans değerine (455843 birey/m2) ulaşmıştır. Nematodlar beslenme tiplerine göre incelenmiş, çalışma bölgesinde tüm beslenme gruplarına rastlanmıştır. Ancak depozitivorlar ve epistratumla beslenenlerin genel olarak baskın olduğu görülmüştür. Beslenme grupları ile çevresel parametreler arasındaki ilişkiler araştırılmış ve buna göre pH, %silt içeriği ve %kaba kumun beslenme gruplarının kompozisyonunda etken olduğu belirlenmiştir. Nematodlar ayrıca ekolojik gruplarına göre irdelenmiş, Maturity İndeks ve c-p değerleri hesaplanmıştır. Bu analizlere göre araştırma bölgesinin ekolojik kalite durumunun mevsimsel dalgalanmalar gösterdiği gözlenmiştir. Tespit edilen tüm nematodların mevsimsel olarak seçilen dört aya ait bireyleri incelenmiş ve mevsimsel dinamikleri verilmiştir. Tezin son bölümünde ise Chromadoridae'nin taksonomik ve ekolojik özellikleri detaylı olarak incelenmiştir. Tez çalışması sonucunda 6 ordo, 25 familya ve 73 genusa ait toplam 133 takson tespit edilmiştir. Tespit edilen 133 taksonun 22'si Karadeniz faunası için, 42'si ise Türkiye faunası için yeni kayıttır.