Exposure of larvae to daily thermocycles affects gonad development, sex ratio, and sexual steroids in Solea senegalensis, kaup
| Autor: | Francisco Javier Sánchez-Vázquez, Evaristo L. Mañanós, María J. Bayarri, Jesús Ramos, Borja Blanco-Vives, Luisa Vera |
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| Rok vydání: | 2010 |
| Předmět: |
Male
medicine.medical_specialty Physiology Photoperiod Biology Environment Animal science Aquaculture Internal medicine Genetics medicine Animals Testosterone Sex Ratio Gonadal Steroid Hormones Gonads Muscle Skeletal Molecular Biology Ecology Evolution Behavior and Systematics Solea senegalensis Larva Sexual differentiation Estradiol business.industry Temperature Adaptation Physiological Endocrinology Sex steroid Flatfishes Animal Science and Zoology Female Development of the gonads business Sex ratio |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1932-5231 1932-5223 |
| Popis: | 28 p., 6 figures and references The effect of water temperature during the development of fish larvae on sex differentiation is well known, but not so well known is the impact of the daily thermocycles. Our aim was to investigate the effect of early exposure of Senegal sole larvae to different temperature cycles on gonad development, sex ratio and sex steroid (11-ketotestosterone, 11-KT; estradiol, E2; and testosterone, T) content in muscle extracts of juveniles. From 1 to 97 DPH (days post-hatching) fish larvae and post larvae were subjected to three temperature regimes: TC (Thermophase-Cryophase); CT (Cryophase-Thermophase); and constant temperature. In fish exposed to TC, sex determination occurred earlier, since 90% of soles were males/females at 110 DPH, whereas 45% of fish under CT were undifferentiated at that time. Fish under TC showed the highest growth rates, followed by fish under constant temperature and by fish under CT, the differences being statistically significant between the TC and CT groups. Regarding sex ratio, juveniles exposed to TC showed a higher proportion of females than fish under CT or constant temperature. Under TC, fish showed the highest concentration of E2, while 11-KT concentration was highest in fish under CT and constant temperature. Fish under constant temperature and CT showed higher T levels than those under TC. These results provide the first insights into the effect of daily thermocycles on sex differentiation in fish, and underline the key role of natural environmental cycles on the control of sex ratios during larval development, which may be applied to the manipulation of sex ratio in aquaculture. This research was funded by the Spanish Ministry of Science and Innovation (MICINN) by projects “Circasole” AGL2007-66507-C02-02 and “Reprosole” AGL2006-13777-C03. AQUAGENOMICS 28502 (Consolider-Ingenio Program), and FUNDACIÓN SENECA by project 05690/PI/07 awarded to Francisco Javier Sánchez Vázquez and Generalitat Valenciana project ACOMP/2006/202 to Evaristo Mañanós. Thanks are also due to COST ACTION 867 (Fish Welfare) and FA0801 (Larvanet), where part of these results were presented and discussed |
| Databáze: | OpenAIRE |
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