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Öğe Bazı kemikli balıkları enfekte eden miksozoa parazitlerinin morfolojik ve moleküler yöntemlerle belirlenmesi(Sinop Üniversitesi, 2019) Okkay, Sevilay; Özer, AhmetKaradeniz'in Sinop kıyılarında gerçekleştirilen bu tez çalışmasında bazı kemikli balıkları enfekte eden miksozoa parazit türlerinin morfolojik ve moleküler yöntemlerle belirlenmesi ve filogenetik ilişkilerinin ortaya çıkarılması amacıyla Eylül 2015- Ağustos 2016 tarihleri arasında 15 balık türüne ait örnekler (Alosa immaculata, Spicara maena, Atherina hepsetus, Diplodus annularis, Trachurus trachurus, Neogobius melanostomus, Gobius niger, Gaidropsarus mediterraneus, Scorpaena porcus, Solea solea, Parablennius tentacularis, Parablennius sanguinolentus, Sarda sarda, Engraulis engrasicolus ve Symphodus cinereus) miksozoa parazitleri yönünden incelemeye tabi tutuldu. İncelenen balık türlerinden 13 tanesinde toplamda 16 parazit türü morfolojik olarak tanımlandı. Bu balıkların enfekte olan dokularındaki miksozoa parazitlerinin enfeksiyon oranları (%) ve yoğunlukları ile varlığı tespit edilen parazit türlerinin tamamında morfolojik ve 5 tür için moleküler düzeydeki tanımlamalar yapıldı. Elde edilen bulgulara göre Kudoa niluferi, K. anatolica ve Ortholinea sp1 türlerinin bilim dünyası için yeni tür kaydı yapıldı. Ayrıca, mevcut literatürde genellikle üriner kese ve nadiren de safra kesesi ve böbrek paraziti olarak bilinen Sinuolinea rebae türünün balık kas dokusunda da bulunduğu ilk kez belirlendi. Bu tez kapsamında ayrıca Ortholinea gobiusi türü parazitin ilk moleküler düzeyli tanımlanması ile Zschokkella iskovi ve Ceratomyxa scorpaeni türü parazitlerin Karadeniz parazit faunasına yeni kaydı sağlandı. Ceratomyxa scorpaeni türüne ait moleküler düzeydeki bulgular Akdeniz'den bildirilen bu türün Karadeniz soy hattı ile olan ilişkilerin tespitine yönelik önemli bulgular içermektedir.Öğe Comparative Diplectanum aequans (Monogenea) infestations in cultured European seabass (Dicentrarchus labrax) in the Black Sea and the Aegean Sea(Ege Univ, Fac Fisheries, 2019) Ozer, Ahmet; Okkay, Sevilay; Orturk, Turkay; Baki, Birol; Acar, Gokce; Guven, Arzu; Ozturk, Diiara KayaIn the present study, monogenean infestations were investigated on the gills of the European seabass Dicentrarchus labrax grown in culture cages located at Yakakent coast of the Black Sea and Milas coast of the Aegean Sea. Parasitological investigations were conducted simultaneously at both localities during September 2014, February and April 2015. While a total of 100 fish specimens were examined from Yakakent samples whose average length was 19.37 cm, a total of 88 fish specimens were examined from Milas samples whose length was 22.67 cm in average. Only one monogenean species Diplectanum aequans was recovered from investigated fish specimens at both sampling localities. Infestation prevalence (%) and mean intensity values of D. aequans were 89.0% and 9.6 +/- 0.8 in Yakakent samples while those infestation indices were 90.9% and 13.3 +/- 1.2 in Milas samples, respectively. The difference between the infestation prevalence (%) values of D. aequans at both sampling localities was not statistically significant, on the other hand, the difference was statistically significant in the mean intensity values at both locations. Diplectanum aequans showed a homogeneous distribution in all gill arches of fish without any statistically significant difference.This is the first comparative study on the infestation of D. aequans on the gills of European sea bass D. labrax cultured in the Black Sea and the Aegean Sea.Öğe First report of Ceratomyxa scorpaeni (Cnidaria: Myxozoa) from Scorpaena porcus in the Black Sea(Magnolia Press, 2021) Okkay, Sevilay; Gurkanli, C. Tolga; Ciftci, Yilmaz; Yurakhno, Violetta; Ozer, AhmetMembers of the class Myxosporea Butschli, 1881 have a cosmopolitan distribution in a wide variety of fish species worldwide. In the present study, the black scorpionfish Scorpaena porcus collected from the Sinop coasts of the Black Sea was investigated for myxosporean parasites using both conventional and molecular methods in the period between September 2015 and August 2019. Using morphological and morphometric data, the myxosporean parasite Ceratomyxa scorpaeni Garbouj, Rangel, Castro, Hmissi, Santos, Bahri, 2016 was identified in the gall bladder of host fish. Molecular analysis of the 18S rDNA gene confirmed the identity of this parasite as C. scorpaeni. This is the first report of its occurrence in the Black Sea.Öğe Infection of Kudoa anatolica (Cnidaria: Myxozoa): Impact on the Nutritional Composition of Atherina hepsetus (Atherinidae) Flesh(Taylor & Francis Inc, 2023) Ozer, Ahmet; Kaya, Yalcin; Okkay, Sevilay; Kocatepe, DemetMediterranean sand smelt Atherina hepsetus, whose flesh was infected by Kudoa anatolica, was investigated for its impacts on the nutritional composition of host fish. Based on the infection densities of K. anatolica, fish were grouped to have uninfected control (A), slightly (B), moderately (C), and highly infected (D). While there were no significant changes in the crude protein (CP), crude lipid (CL), and energy contents (p > .05), significant changes were determined in the total amino acid content between groups (p < .05). The present study proved changes in the proximate, fatty acid, and amino acid composition in flesh and the negative impacts of a Kudoa species.Öğe Light and Scanning Electron Microscopic Observations on Grillotia erinaceus (Cestoda: Trypanorhyncha)(Istanbul Univ Press, Fac Aquatic Sciences, 2020) Ozer, Ahmet; Ozturk, Turkay; Okkay, Sevilay; Yurakhno, Violetta; Kornyychuk, JuliaIn the present study, the plerocercoids of Grillotia erinaceus were obtained from the wall of the anterior oesophagus, stomach, pyloric caeca and liver of teleost Black Sea whiting Merlangius merlangus and adults were collected from the intestine of elasmobranch thornback rays Raja clav- ata caught by commercial fishing vessels off Sinop, Turkey. Standard parasitological investigation methods were applied and morphological diagnostic features of the whole parasite, bothria, scolex, tentacular armatures and tentacles were studied in detail using a light and Scanning Elec- tron Microscope (SEM). The plerocercoids of this parasite had a total length of 5.96 mm on average and this was 21.6 mm on average in adults. The measurement data of all morphological diagnostics are provided and photomicrographs of each part of the parasite are presented. This study also provides the detailed morphological features of both plerocercoids and adults of G. erinaceus in M. merlangus and R. clavata for the first time in the Turkish coasts of the Black Sea.Öğe Molecular and morphological description of Ceratomyxa scophthalmi sp. nov. (Myxozoa) infecting Scophthalmus maeoticus and first report of Myxidium finnmarchicum in the Black Sea(Inter-Research, 2022) Ozer, Ahmet; Gurkanl, Cem Tolga; Okkay, Sevilay; Ciftci, Yilmaz; Yurakhno, ViolettaIn the present study, 2 species of myxozoan parasites, the novel Ceratomyxa scophthalmi sp. nov. and Myxidium finnmarchicum, were documented from the gallbladder of Scophthalmus maeoticus inhabiting the Turkish Black Sea coast at Sinop. C. scophthalmi sp. nov. had mostly spherical, clavate, and fine-grained polymorphic plasmodia that ranged in diameter from 16.0 to 29.0 mu m. Spores were arcuate with a convex anterior margin and concave posterior. Valves of spores were highly elongated and unequal in thickness with one valve 1.1-1.3 times thicker than the other. Valves narrowed gradually toward slightly truncated ends. The mean (range) dimensions of spores were 9.4 (8.5-10.0) mu m in length and 49.6 (44.5-55.0) mu m in thickness, with polar capsules that were 3.1 (2.7-3.5) mu m in length and 3.2 (2.7-3.5) mu m in width. Polar filaments were coiled with 4-5 turns. Large numbers of immature forms of C. scophthalmi sp. nov., which were often 'crumpled', and mature forms were found together in the gallbladder bile. Along with morphological differences, phylogenetic analysis based on 18S rDNA, including pairwise nucleotide similarities with other related Ceratomyxa species, suggests C. scophthalmi as a novel species. Moreover, this report provides the first morphological and molecular descriptions of M. finnmarchicum outside of its original geographical location and type host species.Öğe New Locality and Host Record of Some Myxozoan Parasite Species (Cnidaria) off Turkish Coast of the Black Sea(Inst Zoology, Bas, 2020) Okkay, Sevilay; Ozer, AhmetNine marine fish species were studied for the presence of myxozoan parasites: Pontic shad Alosa immaculata, Mediterranean sand smelt Atherina hepsetus, knout goby Mesogobius batrachocephalus, round goby Neogobius melanostomus, black goby Gobius niger, shore rockling Gaidropsarus mediterraneus, thornback ray Raja clavata, grey wrasse Symphodus cinereus and European anchovy Engraulis encrasicolus. Fish were collected from Sinop coasts of the Black Sea. Gills, fins, skin, urinary bladder, kidney, gall bladder, liver, intestine, smooth muscles and gonads of each fish species were examined for myxosporean parasites. Ten myxosporean species, most of them identified at the species level, were found. They were Ortholinea orientalis from Pontic shad and European anchovy, Fabespora nana and Sphaeromyxa sevastopoli from knout goby, Sphaeromyxa sevastopoli and Zschokkella iskovi from shore rockling, Chloromyxum partistriatus from thornback ray, Myxobolus sp. 1 and Ortholinea divergens from grey wrasse, Ortholinea sp. from black goby. Ceratomyxa sp. from Mediterranean sand smelt and Myxobolus sp. 2 from round goby. Infection prevalence and intensity values as well as morphometric data for each parasite species are provided. While Ortholinea orientalis was found in new hosts for the Black Sea, Sphaeromyxa sevastopoli, Ortholinea divergens and Fabespora nana were found in new host for Turkish coast of the Black Sea. Furthermore. Zschokkella iskovi and Chloromyrum partistriatus are new records for the Turkish Black Sea parasite fauna.Öğe New molecular evidence on the members of the genus Ortholinea (Cnidaria, Myxozoa) and the description of Ortholinea hamsiensis n. sp. infecting the urinary bladder of European anchovy Engraulis engrasicolus in the Black Sea(Cambridge Univ Press, 2024) Okkay, Sevilay; Gurkanli, Cem Tolga; Ciftci, Yilmaz; Ozer, AhmetMembers of the genus Ortholinea are among the worldwide distributed myxozoan parasites that mainly infect marine fish. In this study, a new myxosporean species, Ortholinea hamsiensis n. sp., was isolated from the urinary bladder of European anchovy Engraulis engrasicolus collected from the Sinop coasts of the Black Sea. The prevalence and density values of infection were 1.4% and 1-5 individuals in the field of view (1 + ), respectively. Mature myxospores are subspherical with slight tapering down to the less pronounced tip in the frontal view and subspherical in the sutural view. Myxospores measured 9.1 +/- 0.25 (8.8-9.9) mu m in length, 9.2 +/- 0.11 (8.9-9.4) mu m in thickness, and 8.4 +/- 0.33 (8.2-9.1) mu m in width. Two polar capsules equal in size measured 3.1 +/- 0.11 (3.0-3.3) mu m in length and 2.7 +/- 0.11 (2.6-2.9) mu m in width. The polar tubule had 3-4 coils. Along with morphological peculiarities, the results of the 18S rDNA also revealed it to be a new species for science compared to the other species of the genus. In this study, another myxosporean species O. gobiusi was also detected in round goby Neogobius melanostomus with a prevalence of infection value of 4.8% and a density of 1-5 individuals in the field of view (1 + ). The present study also provided the first data of 18S rDNA of O. gobiusi from N. melanostomus and type species of the genus O. divergens from Gobius niger and the phylogenetic relationships of these species with other Ortholinea species have been revealed.Öğe Parasite Fauna of Chub Squalius cephalus (L., 1758) (Actinopterygii: Leuciscidae) from a Stream System in Kocaeli Province, Türkiye(Inst Zoology, Bas, 2023) Okkay, Sevilay; Clzer, AhmedThe parasite fauna of chub Squalius cephalus from the Kaytazdere-Yalakdere stream systems, Sea of Marmara basin, Turkiye, was investigated. Totally, four digenean species (Clinostomum complanatum, Tylo-delphys clavata, Posthodiplostomum sp. and Ichthyocotylurus sp.), one nematode species (Rhabdochona denudata), one monogenean species (Dactylogyrus nanus) and two myxosporean species (Myxobolus sp. 1 and Myxobolus sp. 2) were identified. Overall infection prevalence, mean intensity and mean abundance were 87.0%, 22.1 +/- 2.5, 16.2 +/- 2.0, respectively. Myxobolus sp. 2 was the most prevalent parasite species, followed by Myxobolus sp. 1 and C. complanatum. Dactylogyrus nanus was the most abundant parasite species, followed by C. complanatum and Ichthyocotylurus sp. The species Thylodelphys clavata, Postho-diplostomum sp., Ichthyocotylurus sp., Myxobolus sp. 1 and Myxobolus sp. 2 are new parasite records for S. cephalus as well as new geographical records in Turkiye.Öğe Parasitic isopods on some marine fishes caught from the coasts of Sinop in the Black Sea, Turkey(Ege Univ, Fac Fisheries, 2021) Okkay, Sevilay; Ozer, AhmetMarine fish species such as grey wrasse Symphodus cinereus, common sole Solea solea, knout goby Mesogobius batrachocephalus and rusty blenny Parablennius sanguinolentus were studied for their parasitic isopods on the Sinop coast of the Black Sea. Two cymothoid species (Nerocila bivittata and Nerocila orbignyi) were identified. Nerocila bivittata was found on the body surface and fins of grey wrasse, common sole, knout goby, and N. orbignyi on the dorsal fin of rusty blenny. The prevalence and mean intensity values of each parasite species on fishes were calculated. Fish species mentioned above were all new hosts for N. bivittata and N. orbignyi in the Turkish coast of the Black sea.
