Hatchery performance in a major rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) seed production area of Turkey By M. Kanyılmaz 1 , A. Yılayaz 1 , G. Uysal 1 , H. Sevgili 1 and Sß . S. Tabakoglu 2 1 Mediterranean Fisheries Research, Production and Training Institute, D€ os ßemealtı, Antalya, Turkey; 2 Cß ukurova University Fisheries Faculty, Balcalı, Adana, Turkey Summary This study aims to determine the production characteristics and performance of rainbow trout hatcheries in Seydikemer, Mugla, Turkey where over half of the total production of eyed eggs and juveniles take place. For this purpose six hatcheries with different production scales were selected and coded A, B, C, D, E and F (with capacities of 60, 15, 5.6, 4, 0.95 and 0.6 million juveniles per year, respectively). From each hatchery, 20 females were selected and their egg quali- ties (egg number, diameter and weight, fertilization, eyed egg, hatching, swim-up fry and survival rates at 120 days after hatching) and juvenile growth rates were monitored until the 120 th day after hatching under each farms own con- ditions. The sperm characteristics of 10 broodstock males from each hatchery were also examined. Although fertiliza- tion and eyed egg rates were similar among the farms, hatch- ing, swim-up fry, and survival rates at the 120 th day after hatching differed significantly. The average eyed egg, hatch- ing and survival rates (calculated from selected 20 females) were 72, 55, and 32%, respectively. While sperm characteris- tics except duration of motility (s), were significantly different among the farms, average sperm concentration (per ml), motility (%) and duration of motility (s) in the region were 11.8 9 10 9 , 55.3, and 56.4, respectively. The best hatchery performance was observed in Farm A because of better records and management applications than in the other farms. Introduction Turkey, which is one of the top rainbow trout producers in the world at present, commenced its first commercial produc- tion in the early 1970s with an annual capacity of 10 tonnes (t). Production reached 128 060 t in 2013, accounting for 54.9% of the total country aquaculture production (233.394 t year 1 ) (BSGM, 2014; FAO, 2014; TU _ IK, 2014). At the beginning, the production relied on imported eggs, later changing to a domestic supply with the introduction of hatcheries, with the first built in 1985 in the Seydikemer dis- trict, Mugla. Significant improvements in eyed egg, juvenile, and pan-sized fish production took place in the later years with the abundant supply of high-quality water in the region (Kanyılmaz et al., 2011). There are now 55 farms in the region with a production capacity of 8294 t per year as well as 14 hatcheries that produce circa 192 million juveniles and 137 million eyed eggs per year that are either mixed or all female (BSGM, 2014). Egg and juvenile production in the region can meet about half of the total requirement of Turkey. Despite the leading role of the region in trout seed produc- tion, there is a serious lack of information on efficient hatch- ery management (Kanyılmaz et al., 2011). Previous studies in the region have dealt with other aspects of farms such as the environmental impact, capacity utilization, and economic analyses (Emre et al., 2011; Kanyılmaz et al., 2011; Koc ßer et al., 2013; Koc ßer and Sevgili, 2014). The farms differ signif- icantly from each other in terms of management structure, rearing practices, and environmental conditions. In addition, the increasing levels of inbreeding (T. Arslan, pers. comm., unpubl. data) in the farms emphasize the importance of their hatchery performance. From a fish hatchery perspective, the reproductive performance of males and females (Bromage et al., 1992; Ciereszko and Dabrowski, 1994; Brooks et al., 1997; G€ uner and Tekinay, 2002; Bozkurt, 2006; Bobe and Labbe, 2010; € Ozg€ ur and Bayır, 2013) and other factors such as inbreeding, depression, water temperature, and repeated use of the same fish (Kincaid, 1983; van Heerden et al., 1996; Contreras-Sanchez et al., 1998; Hajirezaee et al., 2009; Pankhurst and King, 2010) should be determined. The pre- sent study aims to determine hatchery performance and man- agement practices in six farms located in Seydikemer during a regular reproduction period in order to have a view of the rainbow trout hatchery situation in Turkey. Materials and methods Selection and categorization of hatcheries Fourteen rainbow trout farms in the Seydikemer district, Mugla, south-west Turkey, were visited in September 2009 and reviewed regarding hatchery performance using a brief questionnaire to select farms for the study, allowing for proper estimates of their technical capacities and facilities; six were selected for the final analysis. Data in the question- naire were related to five main parameters: estimated fertil- ization, eyed egg, hatching, swim-up fry, and survival rates at day-120 after hatching. Two farms were studied in each J. Appl. Ichthyol. (2016), 1–8 © 2016 Blackwell Verlag GmbH ISSN 0175–8659 Received: March 6, 2015 Accepted: December 26, 2015 doi: 10.1111/jai.13063 Applied Ichthyology Journal of