3 research outputs found
Feminization of the Nile tilapia Oreochromis niloticus by estradiol-17? Effects on growth, gonadal development and body composition
Conditions for the feminization of undifferentiated XY fry of Nile tilapia (Oreochromis niloticus) fed on a diet supplemented with estradiol-17? (E2) were investigated in order to produce functional phenotypical females (genetic males). Different E2 concentrations (60 and 120 mg kg-1) were tested over a period of 30 days in a closed recirculating system. Fry were fed ad libitum at 1-h intervals. The effects on growth, gonadal development and body composition were evaluated at sexual maturity. Sex-reversed females were produced in both E2 treatments. The proportion of males was significantly lower (p < 0.05) in both E2 treatments compared to the control group. Fish with atypical papilla and normal ovaries were producedin both E2 concentrations. These fish were considered sex-reversed females. Growth was significantly higher (p < 0.05) in the males compared to both the females and the sex-reversed ones in all groups analyzed. No testicular tissue was observed in any of the ovaries of the sex-reversed females analyzed. The percentage of fat in muscle increased and that of protein decreased significantly (p < 0.05) in the sex-reversed females compared to that observed in the control group. Identified sex-reversed females will be used in the production of YY males through mating with normal males, as part of a developing breeding program to produce a male genetic population in the southern region of Mexico
Larval Development in Tropical Gar (Atractosteus tropicus) Is Dependent on the Embryonic Thermal Regime: Ecological Implications under a Climate Change Context
This article belongs to the Special Issue Current Advances and Challenges in Fisheries and Aquaculture Science: Feature Papers for the New Journey of Fishes[EN] In ectotherm species, environmental temperature plays a key role in development, growth, and survival. Thus, determining how temperature affects fish populations is of utmost importance to accurately predict the risk of climate change over fisheries and aquaculture, critical to warrant nutrition and food security in the coming years. Here, the potential effects of abnormal thermal regimes (24, 28 and 32 °C; TR24, TR28, and TR32, respectively) exclusively applied during embryogenesis in tropical gar (Atractosteus tropicus) has been explored to decipher the potential consequences on hatching and growth from fertilization to 16 days post-fertilization (dpf), while effects on skeletal development and body morphology were explored at fertilization and 16 dpf. Egg incubation at higher temperatures induced an early hatching and mouth opening. A higher hatching rate was obtained in eggs incubated at 28 °C when compared to those at 24 °C. No differences were found in fish survival at 16 dpf, with values ranging from 84.89 to 88.86%, but increased wet body weight and standard length were found in larvae from TR24 and TR32 groups. Thermal regime during embryogenesis also altered the rate at which the skeletal development occurs. Larvae from the TR32 group showed an advanced skeletal development, with a higher development of cartilaginous structures at hatching but reduced at 16 dpf when compared with the TR24 and TR28 groups. Furthermore, this advanced skeletal development seemed to determine the fish body morphology. Based on biometric measures, a principal component analysis showed how along development, larvae from each thermal regime were clustered together, but with each population remaining clearly separated from each other. The current study shows how changes in temperature may induce craniofacial and morphological alterations in fish during early stages and contribute to understanding the possible effects of global warming in early development of fish and its ecological implicationsSIThis work was partially funded by “Study of the digestive physiology in larvae and juveniles of tropical gar (Atractosteus tropicus) based on histological, biochemical and molecular techniques” project (Ref. CB-2016-01-282765) from the National Council for Science and Technology (CONACyT) of Mexico. I.F. acknowledges the funding from the MICIU and the European Social Fund, “The European Social Fund invests in your future” through the RamĂłn y Cajal (Ref. RYC2018-025337-I) contract from the Plan Estatal de InvestigaciĂłn CientĂfica y TĂ©cnica e InnovaciĂłn 2017–2020Authors also thanks the support from the RED LARVAplus “Estrategias de desarrollo y mejora de la producciĂłn de larvas de peces en IberoamĂ©rica” (117RT0521) funded by the Programa Iberoamericano de Ciencia y TecnologĂa para el Desarrollo (CYTED
FamĂlies botĂ niques de plantes medicinals
Facultat de Farmà cia, Universitat de Barcelona. Ensenyament: Grau de Farmà cia, Assignatura: Botà nica Farmacèutica, Curs: 2013-2014, Coordinadors: Joan Simon, Cèsar Blanché i
Maria Bosch.Els materials que aquĂ es presenten sĂłn els recull de 175 treballs d’una famĂlia botĂ nica d’interès medicinal realitzats de manera individual. Els treballs han estat realitzat
per la totalitat dels estudiants dels grups M-2 i M-3 de l’assignatura Botà nica Farmacèutica
durant els mesos d’abril i maig del curs 2013-14. Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pel professor de l’assignatura i revisats i finalment co-avaluats entre els propis estudiants. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botà nica farmacèutica