| Summary: | 4 pages, 1 table.-- XI Congreso Nacional de Acuicultura, Vigo 25-28 de septiembre de 2007 [EN] Under intensive culture conditions, the sex ratio in the turbot (Scophthalmus maximus L.) is close to 1M: 1F, but, in some commercial facilities, a considerable deviation has been described in this ratio in favour of males. The reason for this alteration in the sex ratio may be the rearing temperature acting on sex differentiation, as has been described for numerous species of fish. In order to study this hypothesis, three groups of turbot post-larvae were cultured at 21ºC (TC), 18ºC (TM) and 15ºC (TF), from 35 days of life up to 4 months of life. At the end of the treatment, fish were reared at ambient temperature up to 12 months of age. Sex ratios in the different groups were determined by histological analysis and visually. Growth in size and weight was determined on a regular basis, up to 12 months of life, in order to determine the effect of temperature and to check for the existence of the compensatory growth. At the end of the experiment (12 months of life), the weight of the groups cultured at a low temperature was significantly less than that of the groups TM and TC (p<0.05), and the weight of the males was greater than that of the females in all groups (p<0.05). Size was also greater in males than in females in groups TM and TF (p<0.05), and similar in group TC. At this age, sex ratio were not significantly different between the three groups, which indicates to that in the turbot, the sex ratios is not thermodependent or, that treatment was applied after de termolabel period [ES] Bajo condiciones de cultivo intensivo, la proporción de sexos del rodaballo (Scophthalmus maximus L.) es próxima a un macho (M) una hembra (H), sin embargo en algunas instalaciones comerciales ha sido descrita una desviación importante de esta proporción a favor de los machos. La causa de esta alteración en la proporción de sexos puede ser la temperatura de cultivo que actúa sobre la diferenciación sexual, como ya ha ...
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