Aquaculture Research, 2009, 41, 129^134 doi:10.1111/j.1365-2109.2009.02314.x Spawning induction of pejerrey Odontesthes bonariensis in captivity using sustained-release gonadotropin releasing hormone agonist implants LeandroA. Miranda & Gustavo M. Somoza Laboratorio de Ictio¢siolog|¤a yAcuicultura, Instituto de Investigaciones Biotecnolo¤gicas-Instituto Tecnolo¤gico de Chascomu¤s (IIB-INTECH) (CONICET-UNSAM), Buenos Aires, Argentina Correspondence: L A Miranda, Laboratorio de Ictio¢siolog|¤a y Acuicultura, Instituto de Investigaciones Biotecnolo¤gicas-Instituto Tec- nolo¤gico de Chascomu¤s (IIB-INTECH) (CONICET-UNSAM), Camino de Circunvalacio¤n Laguna Km, 6 (B7130IWA) Chascomu¤s, Buenos Aires, Argentina. E-mail:
[email protected] Abstract nos Aires, Argentina. Its typical habitats are ‘lagu- nas’, the most common lentic water bodies of the The aim of this study was to induce and synchronize Argentinean pampas, which frequently have salinity spawning of pejerrey Odontesthes bonariensis (Valen- levels from 1 to 24 g L À 1 (Toresani, Lo¤pez & Go¤mez ciennes, 1835), using gonadotropin releasing hor- 1994). It has been reported recently that pejerrey mone agonist (GnRHa) implants. In the ¢rst has better survival and growth performance in experiment, the ovarian condition was assessed by brackish water, and the positive e¡ects of salinity on ovarian biopsies and the measurement of the genital ionic and osmoregulatory balance and mitigation of pore width (GPW). Females having the leading clutch stress response were also demonstrated (Somoza, of oocytes with a diameter of around 800^900 mm Miranda, Berasain, Colautti, Remes-Lenicov & and a GPW between 4.5 and 5.5 mm were treated Strˇssmann 2008).