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Öğe The Anaesthetic Effects of Quinaldine Sulphate, Muscle Relaxant Diazepam and Their Combination on Convict Cichlid, Cichlasoma nigrofasciatum (Gunther, 1867) Juveniles(Medwell Online, 2010) Bircan-Yildirim, Yasemin; Genc, Ercument; Turan, Funda; Cek, Sehriban; Yanar, MahmutThe goal of this study was to determine the safety dosage of anaesthetic Quinaldine Sulphate (QS) alone and together with a muscle relaxant, Diazepam (D) on Convict cichlid, Cichlasoma nigrofasciatum (0.54+/-0.01 g) juveniles for ornamental fish sector. The trial showed that the QS with D administration significantly increased the anaesthesia level in the Convict cichlid. The fish entered light anaesthesia at 9.75 ppm QS+0.5 ppm D (0.83+/-0.02 min). Moreover, a deep anaesthesia level was reached at 9.75 ppm QS+1 ppm D (1.20+/-0.09 min) as compared to 13 ppm of QS (6.40+/-0.28 min). When used together with QS and D eliminated the excitement and hyperactivity of the fish compared to QS alone. In addition, no mortality occurred in any anaesthesia levels except high concentrations (40-54 ppm QS). This study indicate that the advisable light and deep phases of anaesthesia for experimental treatments, handling, immobilization and transportation of the convict cichlid juveniles were achieved with dosages of 9.75 ppm QS+0.5 ppm D and 9.75 ppm QS+1 ppm D, respectively.Öğe Biological observations on the common guitarfish Rhinobatos rhinobatos from Iskenderun Bay (Turkey, Eastern Mediterranean)(Brill, 2009) Cek, Sehriban; Basusta, Nuri; Demirhan, Sefa Ayhan; Karalar, MuratHistological examination of the gonads showed that spermatogenesis occurs in every male R. rhinobatos collected in autumn and winter months of the year. The testis was composed of lobes having numerous spermatocysts in a dorsoventral zonated arrangement. Present results suggest that since R. rhinobatos have a cystic mode of spermatogenesis it can be used as a model for biomedical and toxicological studies. Eight stages of maturation for females and seven stages of maturation for males were identified. Moreover, vitellogenic oocytes were consistently found in every female collected during the summer months. In vitellogenic oocytes, yolk is present as pleomorphic droplets and very often; small yolk droplets have a crystalline configuration. These data suggest that both sexes are reproductively active at different times of the year. Both, the right ovary/testis and the left ovary/testis were functional. Ripe oocytes in the ovaries were usually symmetrically distributed. The population consisted of aplacental viviparous individuals with lecithotrophic embryo development. Although, sex ratios of R. rhinobatos were not significantly different from the expected 1:1 ratio (p>0.05), slightly female biased sex ration were recorded. (C) Koninklijke Brill NV, Leiden, 2009Öğe Certain reproductive characteristics of the freshwater mussel Unio terminalis delicates (Lea, 1863) in Golbasi Lake, Turkey(Wiley, 2006) Cek, Sehriban; Sereflisan, HulyaThe aquaculture potential of Unio terminalis has been considered, but is hindered by a lack of knowledge about the reproductive characteristics that promote yields. The present study describes the seasonal reproductive cycle, gonad structure and sex ratio of the freshwater mussel U. terminalis. A total of 695 individuals were collected in monthly samples from October 2004 to September 2005 in Golbas iota Lake, Turkey. Calculation of the gonadosomatic index and histological examination of the gonads showed that gametogenesis began in winter, and spawning occurred in summer and early autumn. Five stages of oogenesis and five stages of spermatogenesis were identified. Spermatogenesis followed a pattern similar to that of typical oogenesis. The population consisted of dioecious individuals. Although sex ratios of U. terminalis were not significantly different from the expected 1:1 ratio (P > 0.05), slightly female-biased sex ratios were recorded. These results and existing data on mussel meat, phytoplankton production, availability of mussel spat, water quality and growth performance suggest that U. terminalis would be a great source for use in future aquaculture attempts.Öğe Early gonadal development and sex differentiation in rosy barb (Pundus conchonius)(Brill Academic Publishers, 2006) Cek, SehribanThe main objective of this study was to describe the early gonadal development and to examine the process of sex differentiation in male and female P conchonius under laboratory conditions. First evidence of primordial germ cells was observed on the day of hatching. The sex differentiation in leptotene, zygotene, pachytene and diplotene stages was clearly detected. Differentiation started from the mid-mid posterior part of the gonads. Actual sex differentiation occurred between 18-21 days and 36-40 days post-hatching in females and males, respectively. Histological sex differentiation differences were clear between males and females; in males, gonads had a smooth surface, were less stained, arrow-shaped, with germ cells located alone in the stroma, and number of germ cells ranging from two to ten per section, whereas in females, gonads had a rough surface, were more stained, wider, with germ cells multiplying rapidly and forming clusters, and number of germ cells ranged from 2 to 58 per section. The numbers of germ cells within the two gonad types were significantly different in favour of females (P < 0.05). Here early developmental stages of the gonads from 0 to 56 days post-hatch are explained.Öğe The effect of 3,5,3'-triiodothyronine on the growth performance in the african catfish (Clarias Gariepinus, Burchell, 1822)(Ege Univ, 2006) Turan, Funda; Cek, SehribanIn this study, African catfish (Clarias gariepinus, Burchell, 1822), having an average initial weight of 35.59 +/- 1.01 g were fed 3,5,3'-triiodothyronine at dietary levels of 1 and 10 mg kg(-1) under laboratory conditions for two months. In this way, the effect of 3,5,3'-triiodothyronine on the growth performance of African catfish was investigated. At the end of experiment, live weight gain and food conversion ratio (FCR) significantly increased in fish fed with 1 mg kg(-1) 3,5,3'-triiodothyronine in comparison with the control groups (P<0.001). But, growth rate was dramatically decreased after 1 mg kg(-1) 3,5,3'-triiodothyronine dosage group.Öğe The effect of varying dietary energy on gonad development at first sexual maturity of the Sharptooth catfish (Clarias gariepinus Burchell, 1822)(Springer, 2009) Cek, Sehriban; Yilmaz, ErdalThe objective of this study was to investigate the effects of five isonitrogenous (35% crude protein) diets having different energy contents; 10.85, 11.82, 12.73, 13.69, and 15.06 MJ DE/kg, respectively, on the gonad development and weight gain of Sharptooth catfish fingerlings. Energy contents of the experimental diets were increased with the increasing amount of soy-acid oil (0, 4, 8.5, 13, 18%) and each group of fish was fed on their respective diets (group I was fed diet I) during 180 days. The gonad maturation was significantly affected by dietary energy. In both sexes, the histological inspections of the gonads did reveal differences among the fish fed different energetic diets. Fish fed diets I, II, and III had significantly heavier and more developed gonads compared to those on diets IV and V. Fish fed the higher energetic diets (IV and V) had partially low numbers of yolky oocytes compared to other groups. The mean GSI values of female and male fish fed with diet III was significantly greater than those fed diets with higher dietary energy; however, higher HSI values were recorded for fish fed with the higher energetic diets (IV and V). Also, the best weight gain for both males and females were recorded from the fish fed diet III (12.73 MJ DE/kg). Therefore, on the basis of the present results, among energy levels tested, 12.73 MJ DE/kg was found to be optimal for healthy gonad development and weight gain.Öğe The Effects of Combined Phytoestrogen Administration on Growth Performance, Sex Differentiation and Body Composition of Sharptooth Catfish Clarias gariepinus (Burchell, 1822)(Central Fisheries Research Inst, 2009) Yilmaz, Erdal; Cek, Sehriban; Mazlum, YavuzThe present study was conducted to investigate the effects of Genesis (G, a commercial mixture of phytoestrogens) oil growth, body composition and sex differentiation of Sharptooth catfish Clarias gariepinus. Genesis is a commercially available product on USA and European markets used for menopausal complaints as an alternative medicine. Different concentrations (0 mg G 30 L(-1), 210 mg G 30 L(-1), 420 mg G 30 L(-1), 630 mg G 30 L(-1), 750 mg G 30 L(-1) and 1500 mg G 30 L(-1)) of Genesis were administered by immersion of newly hatched larvae (averaging 2.27+/-0.12 mg) every 3 days for 30 days then immersion treatments were ceased and all groups reared in the same condition for the later 90 days, a total 120 days experimental period. At the end of the trial, specific growth rate of the females increased with the increasing concentration of Genesis up to 420 mg 30 L(-1) (P<0.05), but different concentrations of Genesis did not affect the growth performance of males (P>0.05). The highest value of protein content (21.60%) was observed from the 420 mg G 30 L(-1) group and found significantly different front the control and other groups (P<0.05). Also, lipid contents were significantly affected by the Genesis concentrations and the highest lipid contents were detected in the 210 mg G 30 L(-1) (5.98%) and the 630 mg G 30 L(-1) (6.66%) groups. Although among the dosages used in the present study, 1500 mg G 30 L(-1) was the most effective dosage that ensured maximum female ratio (69.77%), the sex ratios observed for 0, 210, and 420 mg G 30 L(-1) treatment groups were nearly the expected ratio of 1: 1 (male: female). Therefore, it was concluded that usage of higher doses and treatment durations of Genesis could be more effective for all-female production of the Sharptooth catfish population.Öğe The Effects of Sex Steroids of Endocrine Disrupting Chemicals on Fishes(Ege Univ, Fac Fisheries, 2010) Cek, Sehriban; Sarihan, FatmagunEndocrine disrupting chemicals (EDCs) are anthropogenic compounds that have similar properties as endogenous hormones in vertebrates and they are capable of interfering with the endocrine system. EDCs have been detected in sewage receiving effluents from industries and livestock feedlots. Fish living in the recipients contaminated with these EDCs are reported to have reproductive disabilities. The deleterious effects of EDCs have also been reported in amphibians, reptiles, aves, mammals and humans. The natural estrogen, 17 beta-estradiol (E-2), stimulates the fish liver to synthesize vitellogenin (Vtg). Vtg is the protein that nourishes the maturation of eggs. 17 alpha-ethinylestradiol (EE2) is a potent, synthetic estrogen used in oral contraceptive preparations. It mimics E2 leading to enhanced circulatory Vtg concentrations and male to female sex reversal in fish. 17 beta-trenbolone (Tb), an androgenic steroid, is used as growth promoter in beef cattle. It has been reported to cause declined Vtg concentrations and masculinization in fish. In the near future, many serious problems can be seen in human and wildlife reproduction systems because of EDCs.Öğe The Gametogenic Cycle of Leguminaia whaetleyi (Lea, 1862) in Lake Golbasi, Turkey (Bivalvia: Unionidae)(Wiley, 2011) Cek, Sehriban; Sereflisan, HulyaThe gonadal structure and cycle of the Leguminaia whaetleyi is described for the first time indicating that 5% of this species is simultaneous hermaphrodite. A total of 420 individuals were collected in monthly samples from October 2008 to September 2009 in Golbasi Lake, Turkey. Calculation of the condition index and histological examination of the gonads showed that gametogenesis began in January. Spawning occurred between May and August with one maximum peak in July. Annual maximum oocytes size peaked in July. The population consisted of simultaneous hermaphrodite individuals. Sex ratio of L. whaetleyi was significantly different from the expected 1: 1 ratio (P<0.05), and also female biased sex ratio was recorded. In hermaphrodite specimens, male and female follicles were mixed in the visceral mass but can be clearly distinguished by light microscopy study. L. whaetleyi appears to be a dioecious species in which 25 specimens were simultaneous hermaphrodite and under certain environmental conditions may be capable of self-fertilization. This suggests that detailed studies on sex ratio of L. whaetleyi may be helpful in understanding unionid phylogeny. J. Exp. Zool. 315: 30-40, 2011. (C) 2010 Wiley-Liss, Inc.Öğe HISTOLOGICAL STUDIES ON GAMETOGENESIS, HERMAPHRODITISM AND THE GAMETOGENIC CYCLE OF ANODONTA GABILLOTIA PSEUDODOPSIS (LOCARD, 1883) IN THE LAKE GOLBASI, TURKEY (BIVALVIA: UNIONIDAE)(Natl Shellfisheries Assoc, 2009) Sereflisan, Huelya; Cek, Sehriban; Sereflisan, MenderesThis study describes the seasonal reproductive cycle, gonad structure, and sex ratio of the Anodonta gabillotia pseudodopsis. A total or 300 individuals was collected in monthly samples from September 2005 to August 2006 in Golbasi Lake, Turkey. Calculation of the gonadosomatic index and histological examination of the gonads showed that gametogenesis began in winter and spawning occurred in summer and early autumn. Although, Sex ratios or Anodonta gabillotia pseudodopsis were not significantly different from the expected 1: 1 ratio (p > 0.05). slightly female biased sex ration were recorded. Although mature oocytes and spermatozoa were present for almost the entire year, gonadal activity seemed lowest in October and December, when gonad recovery and reorganization were more evident than gametogenesis. Both sexes displayed greatest gonad activity during the summer months of the year. Three types of gonads were identified, which varied according to the proportion of gametogenic tissue. According to our morphologic and histologic observation, Anodonta gabillotia pseudodopsis were classified as accidental or abnormal hermaphrodite (typically in dioecious species) species. The hermaphroditic specimens of A. pseudodopsis had gonads composed predominately of tissue of only female. These results suggest that under certain environmental conditions females may become hermaphrodites and self-fertilization occur.Öğe Masculinization of African catfish (Clarias gariepinus) treated with gokshura (Tribulus terrestris)(Israeli Journal Of Aquaculture-Bamidgeh, 2007) Turan, Funda; Cek, SehribanThe present paper describes the effects of Tribulus terrestris, a masculinization agent, on the sex reversal of African catfish, Clarias gariepinus. One-clay-old hatchlings were immersed in water containing an extract of T. terrestris at a rate of 0, 3, 6, or 9 g/30 I water for 30 days. The 9 g treatment resulted in 80.42% male populations. Morphological and histological examinations of the gonads in all groups revealed no intersex fish. Histological examination of fish treated with T. terrestris revealed no damage to the testes or ovaries. Despite differences in sex ratio, growth rate, ovaries, and testes, fish treated with T. terrestris were histologically similar to fish from the control groups. Survival ranged from 72% in the 3 g group to 80% in the 9 g during treatment and did not significantly differ from the control (p>0.05). The best growth was obtained in the 9 g treatment.Öğe Masculinization of Convict Cichlid (Cichlasoma nigrofasciatum) by immersion in Tribulus terrestris extract(Springer, 2007) Cek, Sehriban; Turan, Funda; Atik, EsinWe have examined the effects of Tribulus terrestris (TT), a non-toxic herb, on sex reversal in the Convict Cichlid Cichlasoma nigrofasciatum with the aim of introducing a new environmentally friendly method for masculinization in C. nigrofasciatum. TT is a natural plant product that elevates the testosterone levels in humans and animals. Different concentrations (0.0, 0.10, 0.20 and 0.30 g/l) of TT extract were tested for their effect on sex reversal in C nigrofasciatum by immersing newly hatched offspring once weekly for 2 months in TT extract. Of the dosages used in the present study, 0.30 g/l TT was the most effective in terms of masculinization, resulting in a maximum male ratio of 87.23% (P < 0.001). Sex ratios of 79 and 85% at 0.10 and 0.20 g/l TT, respectively, were also significantly different from the expected 1:1 ratio (P < 0.001). Histological examinations revealed that the testes of fish treated with TT extract contained all stages of spermatogenesis, clearly demonstrating that the administration of TT extract to C. nigrofasciatum stimulated spermatogenesis. Total survival rates in all treatments and the control were uniformly high, ranging from 88.57 to 90% (P > 0.05). We concluded that TT had no negative effect on the survival rate of C nigrofasciatum. In addition, all groups of TT-treated fish exhibited successful growth acceleration compared to the control group, but only the 0.30 g/l TT treatment significantly improved the growth rate of C nigrofasciatum. (P < 0.01.). Sex reversal in C. nigrofasciatum demonstrated that TT-treated 0-day-old larvae showed successful sex reversal, spermatogenesis and a better growth rate than untreated progenies.Öğe Reproductive biology of the common cuttlefish (Sepia officinalis Linnaeus, 1758) in Iskenderun Bay (Northeastern Mediterranean Sea)(Natl Inst Science Communication-Niscair, 2014) Duysak, Onder; Ozcan, Gulnaz; Cek, Sehriban; Tureli, CananMorphometric characters and reproductive biology were studied in S. officinalis collected at different seasons from the Iskenderun Bay, Turkey. A total of 2006 specimens (992 female, 1014 male) were sampled from September 2005 to August using a Mediterranean type deep trawl (22 mm mesh size). Mean mantle lengths for female and male were 9.83 +/- 1.66, 9.40 +/- 1.76 cm and the mean weights were 135.78 +/- 6.71g, 115.34 +/- 6.29g, respectively. Sexual maturity lengths were calculated as 12.04 for females and 10.30 cm for males. Mean diameter of eggs was measured as 5.367 +/- 9.12 mm per spawning period. Spermatophore lengths were estimated to range from 2.8 +/- 1.05 to 12.4 +/- 2.11mm. Population consisted of gonochoristic induviduals. Although, sex ratio of Sepia officinalis were not significantly different from the expected 1:1 ratio (p>0.05), a slightly male biased sex ratio was recorded.Öğe The Reproductive Cycle of Potomida littoralis (Cuvier, 1798) (Bivalvia: Unionidae) in Lake Golbasi, Turkey(Zoological Soc Pakistan, 2013) Sereflisan, Hulya; Cek, Sehriban; Sereflisan, MenderesIn this work, reproductive cycle of Potomida littoralis, including histological description and indices of gonad maruration were investigated. There is no data previously available on the species. A total of 300 individuals were monthly collected from September 2009 to August 2010 in Golbasi Lake, Turkey. P. littoralis is dioecious and although males tended to predominate, the sex ratio was not significantly different from the expected 1:1 ratio (p > 0.05). Calculation of the condition index (CI), gonadosomatic index (GSI) and histological examination of the gonads showed that gametogenesis began in January. Spawning occurred in June. Annual maximum GSI value peaked in May. A decrease of CI was observed during gametogenesis. When mussels had the highest GSI value, CI was the lowest value. This results suggest that gametogenesis and reproductive cycle are the key factor in mussels physiology and important for captive breeding/artificial mussels production and conservation status (e.g. When to obtain gravid females, when to relocate, when to restock, when to introduce fish host, when not to allow harvesting).
