Cobia (Rachycentron canadum) is widely recognized as an emerging aquaculture species (Benetti, Orhun, Sardenberg, O’ Hanlon,Welch, Hoening, Zink, Rivera, Denlinger, Bacoat, Palmer & Cavalin 2008). Its culturehas attracted the interest of research institutions and the private sector in Brazil, but it was not until 2008 that permissions for cobia cage culture in Brazil were granted by the Ministry of Fisheries and Aquaculture (MPA). In order to better understand the performance of cobia culture in Brazil, an experimental production of this species was conducted oi the coast of Rio de Janeiro, Brazil (23106 05400S, 44115 05000W) in nearshore cages. The weather is tropical, and the average water temperature is around 25 1C, ranging from a low of19 1C in the winter up to 30 1C in the summer. Depth in the area averages 6^7mand the site is fairly protected from the open sea, characterizing an area with limited carrying capacity. However, it was suitable for this preliminary evaluation of cobia performance, because stocking density was planned to be lowand it was protected from theft. Cobia juveniles (50 days of age, weight1.5 1gand total length 7 3 cm) were transported in transparent plastic bags (100 L) ¢lled with 30 L of water and approximately 70 L of gaseous oxygen to achieve a concentration of 12mgO2 L . Bags were sealed, packed in a truck and transported during 15 h to the harbour (670 km). Once the bags were transferred to the boat, they were taken to the culture site (15 km), totaling 17 h of transport. Temperature and salinity weremaintained at 20 1Cand 32 ppt respectively. Fish density during transport was 2 g L , below the limit of 20 g L 1 recommended by Colburn, Walker, Berlinsky and Nardi (2008). Cobiawere reared in a three-phase system in nearshore cages for12 months according to the following protocol. Phase 1 (nursery): The nursery phase lasted for 1 month. Following transport, juveniles were stocked in nine nurserycages measuring 2 3 2m (mesh size 3mm), resulting in the usable volume of 10m. Cages were made of high-density polyethylene. Stocking density was 0.02 kgm 3 or 130 individualsm . Fish were fed four times daily with a dry diet (50% crude protein and 9% fat, INVE, Grantsville, UT, USA). Phase 2: This intermediary phase lasted for 4 months, from March to July 2008. Upon ¢nishing the nursery phase, ¢sh were kept in the same cages, but the mesh size was increased to12mm.The initial stocking density was 4.6 kgm 3 and from this moment on, cobiawere fed three times per day on frozen cut sardines (Family Clupeidae). Phase 3 (grow-out): During 8 months (from August 2008 to March 2009), ¢sh were reared in a cylindrical cage 2.3m high and 7.5m in diameter, providing the volume of 90m (mesh size was 20mm). Initial stocking density for the grow-out phase was 3.1kgm 3 and cobiawere also fed on frozen cut sardines. Cages were cleaned fortnightly when the mesh size was up to 12mm; however, the larger mesh (20mm) was cleaned every 2 months. Cleaning the Aquaculture Research, 2011, 42, 832^834 doi:10.1111/j.1365-2109.2010.02770.x