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Öğe 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 THE EFFECT OF STOCKING DENSITY ON GROWTH AND SURVIVAL OF THE FRESHWATER MUSSEL UNIO TIGRIDIS (BIVALVIA: UNIONOIDEA)(Inst Malacol, 2011) Sereflisan, Hulya; Yilmaz, ErdalThe effects of four stocking densities of 20, 40, 60, 80 mussels/m(2) on growth of Unio tigridis were investigated. The growth of the freshwater mussel U. tigridis in cages was studied for a year from March 2003 to April 2004 in Lake Golbasi. Juvenile mussels with the initial weight of 0.64 +/- 0.08 g were stocked in metal cages placed on the lake bottom. Growth in live weight, shell length, width and height was measured monthly for the four different stock groups. Chlorophyll a, magnesium (Mg), nitrite (NO2), nitrate (NO3), amount of organic matters, ammonia (NH3), phosphate (PO4), silica (Si) and calcium (Ca) were also analyzed monthly. All water quality parameters were within proper limits for mussel culture. At the end of the study, the greatest live weight (5.55 +/- 0.03 g) was obtained from 40 mussels/m(2), with 3.5 2 +/- 0.02 cm and 1.47 +/- 0.03 cm as length and width values, respectively. The greatest height was determined in a stocking rate of 60 mussels/m(2), with 1.99 +/- 0.03 cm. Therefore, juveniles should be stocked in early spring for U. tigridis at a level of 40-60 individuals/m(2).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 The gastropod fauna and their abundance, and some physicochemical parameters of Lake Golbasi (Hatay, Turkey)(Tubitak Scientific & Technological Research Council Turkey, 2009) Sereflisan, Hulya; Yildirim, M. Zeki; Sereflisan, MenderesAn investigation was carried out on the native gastropod species in Lake Golbasi, Hatay During the research 3 species belonging to the subclass Pulmonata (Gyraulus piscinarum, Radix labiata, Amsus leucostoma) were detected along with 9 species of the subclass Orthogastropoda (=Prosobranchia) including Theodoxus jordani, Semisalsa contempta, Semisalsa longiscata, Bithyma phialensis, Valvata saulcyi, Valvata piscinalis, Melanoides tuberculatus, Melanopsis praemorsa ferussaci, Melanopsis costata costata. These gastropod species were collected from 4 stations chosen in the lake. Furthermore, turbidity, dissolved oxygen, pH, and temperature were measured at the sampling sitesÖğe Offshore Farming of the Mediterranean Amberjack (Seriola dumerili) in the Northeastern Mediterranean(Israeli Journal Of Aquaculture-Bamidgeh, 2011) Yilmaz, Erdal; Sereflisan, HulyaThe growth rate, survival, and feeding parameters of Mediterranean amberjack (Seriola dumerili Risso, 1810) cultivated in offshore cages in the Gulf of Iskenderun (Hatay, Turkey) were investigated from July 2006 to March 2008. Two offshore cages (339 m(3)) were placed at a depth of 10 m in a sheltered area 500 m off the coast. Juveniles (101.97 +/- 14.54 g), caught with seine nets 400-1200 m from the coast, were stocked in the cages at 250 per cage. Fish in one cage, Group A, were fed commercial pellets for all 20 months whilst fish in the second cage, Group B, were fed pellets for the first 16 months and frozen sardines for the following four. The mean live weight, survival, feed conversion ratio, daily feed consumption, and water quality parameters were recorded monthly. Group B reached a significantly (p < 0.05) greater weight (2785.00 +/- 64.91 g) than Group A (2441.14 +/- 38.13 g). Food conversion ratios ranged 1.16-2.46 for group A and 1.10-2.28 for group B, low when compared with other studies on amberjacks in the Mediterranean. Average mortality was 25%, due to a Zeuxapta seriolae (Monogenea: Heteraxinidae) infection in December 2006 (20%) and fish handling for measurement in June 2007 (similar to 5%). The farmed amberjacks had significantly higher protein and lipid contents than their wild counterparts at the end of the 20-month feeding period. Amberjacks found frozen sardines more appealing than pellets, especially during the winter. In conclusion, it is advised to feed Mediterranean amberjack frozen sardines or other trash fish during the winter grow-out period. Their rapid growth rate, as well as their adaptability to farming, make offshore net cages a promising system for the aquaculture of this species.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).
