Yazar "Özer, A" seçeneğine göre listele

Listeleniyor 1 - 8 / 8
  • [ X ]
    Öğe
    Co-existence of Dactylogyrus anchoratus Dujardin, 1845 and D-extensus Mueller & Van Cleave, 1932 (Monogenea), parasites of common carp (Cyprinus carpio)
    (Walter De Gruyter Gmbh, 2002) Özer, A
    Co-existence between potentially competing species, Dactylogyrus anchoratus and D. extensus parasitising common carp (Cyprinus carpio L) from the two localities in northern Turkey has been studied. The distribution of these two dactylogyrids; on mirror and scaled varieties of common carp according to season and the sex of the host at two environmentally different sampling stations is presented. D. anchoratus was recorded with an infestation prevalence of 21.8 % at Cobanlar (farm) and 34 % at Bektasaga (lake), whilst D. extensus, the dominant species, was recorded with infestation prevalences of 98.7 % at Cobanlar (farm) and 85.1 % at Bektasaga (lake). A possible competitive exclusion by Dactylogyrus extensus over D. anchoratus was determined.
  • [ X ]
    Öğe
    Infection prevalence, seasonality and host specificity of actinosporean types (Myxozoa) in an Atlantic salmon fish farm located in Northern Scotland
    (Folia Parasitologica, 2002) Özer, A; Wootten, R; Shinn, AP
    A total of 28,387 oligochaetes belonging to the families Tubificidae, Lumbriculidae, Naididae and Enchytraeidae were examined at regular intervals for actinosporean infections from October 1996 to August 1998 from a freshwater salmon farm in Nor-them Scotland. A total of 21 types of actinosporeans belonging to seven collective groups synactinomyxon (three types), aurantiactinomyxon (four types), echinactinomyxon (five types), raabeia (six types), triactinomyxon (one type), neoactinomyxum (one type) and siedleckiella (one type) were found. Synactinomyxon type 1, echinactinomyxon type 1 and raabeia type 4 were most abundant. The overall infection prevalence of oligochactes was 2.9%. Aurantiactinomyxon, synactinomyxon and neoactinomyxum were most common in summer and autumn. Raabeia was most common in spring and summer and echinactinomyxon in winter and spring, Siedleckiella was found only in spring and triactinomyxon in all seasons except winter. A positive relationship between water temperature and the number of actinosporean types released was observed. Most actinosporean types were found in only one host species.
  • [ X ]
    Öğe
    Survey of actinosporean types (Myxozoa) belonging to seven collective groups found in a freshwater salmon farm in Northern Scotland
    (Folia Parasitologica, 2002) Özer, A; Wootten, R; Shinn, AP
    A study of the actinosporean fauna of oligochaetes from a freshwater salmon farm in Northern Scotland was carried out from October 1996 to August 1998. Following the examination of 28,387 oligochaete worms belonging to the families Tubificidae, Lumbriculidae, Naididae and Enchytraeidae, five types of echinactinomyxon (four previously described), six types of raabeia (five previously described), three types of synactinomyxon (all previously described), four types of auranti-actinomyxon (three previously undescribed), one type of triactinomyxon (previously described), one type of neoactinomyxum (previously undescribed) and one type of siedleckiella (previously undescribed) were identified. The triactinomyxon type was released from unidentified immature oligochaetes. Of the twenty-one types of actinosporeans found, thirteen types were released from Tubifex tubifex (Muller), three types were released from Lumbriculus variegatus (Muller), three types from both L. variegatus and T. tubifex and two types from immature oligochaetes.
  • [ X ]
    Öğe
    The life cycle of Sphaerospora truttae (Myxozoa: Myxosporea) and some features of the biology of both the actinosporean and myxosporean stages
    (Inter-Research, 2000) Özer, A; Wootten, R
    A previously undescribed echinactinomyxon type actinosporean was shown experimentally to be the alternate stage of Sphaerospora truttae. The echinactinomyxon type spores were found to be released from Lumbriculus variegatus and occasionally Tubifex tubifex. Overall infection prevalence of the echinactinomyxon was 0.14%. Peak release was in March-May each year. S, truttae spores developed in experimentally infected salmon 4.5 mo post-exposure to echinactinomyxon spores. Extrasporogonic stages of S, truttae first appeared in naturally infected salmon in early July and persisted for 8 to 10 wk. Correlation between peak release of echinactinomyxon spores and appearance of extrasporogonic stages of S. truttae is discussed.
  • [ X ]
    Öğe
    The occurrence of three species of Trichodina (Ciliophora: Peritrichia) on Cyprinus carpio in relation to culture conditions, seasonality and host characteristics
    (Nencki Inst Experimental Biology, 2000) Özer, A
    The occurrence of Trichodina mutabilis Kazubski & Migala, 1968; Trichondina acuta Lom, 1961 and Trichodina nigra Lom, 1961 on common carp (Cyprinus carpio L., 1758) was studied with respect to seasonality, host factors and the culture conditions. The sampling period was between June 1994 and May 1995 in the Sinop region of northern Turkey and a total of 125 common carp were investigated. The overall incidence of T. mutabilis infestation was 80.7% in the farm and 61.7% in the lake, whilst it was 44.8% in the farm and 36.1% in the lake for the collective T. acuta - T. nigra group. Spring was found to be the most favoured season. There was no statistically significant preference of the collective T. acuta - T. nigra group to any of the varieties of common carp or the sex of the host. T. mutabilis also showed similar preferences to the collective T. acuta - T. nigra group.
  • [ X ]
    Öğe
    The occurrence of Trichodina domerguei Wallengren, 1897 and Trichodina tenuidens Faure-Fremiet, 1944 (Peritrichia) on three-spined stickleback, Gasterosteus aculeatus L., 1758 found in a brackish and freshwater environment
    (Nencki Inst Experimental Biology, 2003) Özer, A
    Trichodina domerguei Wallengren, 1897 and Trichodina tenuidens Faure-Fremiet, 1944 infestations on three-spined stickleback (Gasterosteus aculeatus L., 1758) were studied in the period from January to May 2000 in the Black Sea coasts of Sinop, Turkey. The overall infestation prevalence and mean intensity level were 60.9% and 109.1 +/- 21.5 trichodinids perfish, respectively. Statistically significant differences existed for the trichodinid species among sites on the fish, among length classes and between the sexes of fish hosts. While T tenuidens itself represent a new parasite record, Gasterosteus aculeatus is a new host record for T domerguei in Turkey. Many structures of the parasites were smaller in March, when the habitat was brackish, compared to May, when waters were fresh.
  • [ X ]
    Öğe
    The relationship between occurrence of ectoparasites, temperature and culture conditions
    (Taylor & Francis Ltd, 1999) Özer, A; Erdem, O
    A 1-year study on the occurrence of ectoparasites on farmed and wild common carp (Cyprinus carpio L., 1758) and their relationship with temperature and culture conditions was conducted between June 1994 and May 1995 at two sites in the Sinop region of northern Turkey. Following the investigation of 125 common carp, Trichodina acuta Lom, 1961, Trichodina mutabilis Kazubski and Migala, 1968, Trichodina nigra Lom, 1960, Trichodinella subtilis Lom, 1959, Apiosoma piscicola Blanchard, 1885, Epistylis sp., Dactylogyrus anchoratus Dujardin, 1845, Dactylogyrus extensus Mueller and Van Cleave, 1932, Gyrodactylus sp. and Argulus foliaceus L., 1758 were identified. Trichodina mutabilis and Dactylogyrus extensus were found to be the most common ectoparasites on both the farmed and the wild common carp. The overall infestation prevalence was 100% on farmed carp and 93.6% on wild carp. Dactylogyrus anchoratus represents a new parasite record for Turkey.
  • [ X ]
    Öğe
    Trichodina domerguei Wallengren, 1897 (Ciliophora: Peritrichia) infestations on the round goby, Neogobius melanostomus Pallas, 1811 in relation to seasonality and host factors
    (Helminthological Soc Washington, 2003) Özer, A
    The occurrence of Trichodina domerguei on the round goby, Neogobius melanostomus, was studied from October 1999 through September 2000. Overall prevalence and mean intensity levels were recorded as 77.9% and 156 43.7 Trichodina per infested fish, respectively. Average host length was 71.1 +/- 2.2 mm. Statistically significant differences of parasite prevalence and intensity in relation to season and length of fish were observed. Seasonal variations were also observed in the dimensions of T. domerguei. Neogobius melanostomus is a new host recorded for T. domerguei. This is the first ecological study of T. domerguei conducted in an alternately brackish and freshwater environment.