Browsing by Author "Izquierdo, Marisol"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Distinguishing the effects of Water volumes versus stocking densities on the skeletal quality during the Pre-Ongrowing Phase of Gilthead Seabream (Sparus aurata)Publication . Dellacqua, Zachary; Di Biagio, Claudia; Costa, Corrado; Pousão-Ferreira, Pedro; Ribeiro, Laura; Barata, Marisa; Gavaia, Paulo; Mattei, Francesco; Fabris, Andrea; Izquierdo, Marisol; Boglione, ClaraGilthead seabream (Sparus aurata) production is a highly valued aquaculture industry in Europe. The presence of skeletal deformities in farmed gilthead seabream represents a major bottleneck for the industry leading to economic losses, negative impacts on the consumers’ perception of aquaculture, and animal welfare issues for the fish. Although past work has primarily focused on the hatchery phase to reduce the incidence of skeletal anomalies, this work targets the successive preongrowing phase in which more severe anomalies affecting the external shape often arise. This work aimed to test the effects of: (i) larger and smaller tank volumes, stocked at the same density; and (ii) higher and lower stocking densities maintained in the same water volume, on the skeleton of gilthead seabream fingerlings reared for ~63 days at a pilot scale. Experimental rearing was conducted with gilthead seabream juveniles (~6.7 ± 2.5 g), which were selected as ‘non-deformed’ based on external inspection, stocked at three different densities (Low Density (LD): 5 kg/m3 ; Medium Density (MD): 10 kg/m3 ; High Density (HD): 20 kg/m3 ) in both 500 L and 1000 L tanks. Gilthead seabream were sampled for growth performance and radiographed to assess the skeletal elements at the beginning and end of the experimental trial. Results revealed that (i) LD fish were significantly longer than HD fish, although there were no differences in final weights, regardless of the water volume; (ii) an increase in the prevalence of seabream exhibiting cranial and vertebral axis anomalies was found to be associated with increased density. These results suggest that farmers can significantly reduce the presence of some cranial and axis anomalies affecting pre-ongrown gilthead seabream by reducing the stocking density.
- Fish larval nutrition and feed formulation: knowledge gaps and bottlenecks for advances in larval rearingPublication . Hamre, Kristin; Yufera, Manuel; Ronnestad, Ivar; Boglione, Clara; Conceicao, Luis E. C.; Izquierdo, MarisolDespite considerable progress in recent years, many questions regarding fish larval nutrition remain largely unanswered, and several research avenues remain open. A holistic understanding of the supply line of nutrients is important for developing diets for use in larval culture and for the adaptation of rearing conditions that meet the larval requirements for the optimal presentation of food organisms and/or microdiets. The aim of the present review is to revise the state of the art and to pinpoint the gaps in knowledge regarding larval nutritional requirements, the nutritional value of live feeds and challenges and opportunities in the development of formulated larval diets.
- Reversal of doxorubicin-Induced bone loss and mineralization by supplementation of Resveratrol and MitoTEMPO in the early development of Sparus aurataPublication . Poudel, Sunil; Izquierdo, Marisol; Cancela, M. Leonor; Gavaia, PauloDoxorubicin is a widely used chemotherapeutic drug known to induce bone loss. The mechanism behind doxorubicin-mediated bone loss is unclear, but oxidative stress has been suggested as a potential cause. Antioxidants that can counteract the toxic effect of doxorubicin on the bone would be helpful for the prevention of secondary osteoporosis. We used resveratrol, a natural antioxidant, and MitoTEMPO, a mitochondria-targeted antioxidant, to counteract doxorubicin-induced bone loss and mineralization on Sparus aurata larvae. Doxorubicin supplemented Microdiets increased bone deformities, decreased mineralization, and lipid peroxidation, whereas Resveratrol and MitoTEMPO supplemented microdiets improved mineralization, decreased bone deformities, and reversed the effects of doxorubicin in vivo and in vitro, using osteoblastic VSa13 cells. Partial Least-Squares Discriminant Analysis highlighted differences between groups on the distribution of skeletal anomalies and mineralization of skeleton elements. Calcium and Phosphorus content was negatively affected in the doxorubicin supplemented group. Doxorubicin reduced the mRNA expression of antioxidant genes, including catalase, glutathione peroxidase 1, superoxide dismutase 1, and hsp90 suggesting that ROS are central for Doxorubicin-induced bone loss. The mRNA expression of antioxidant genes was significantly increased on resveratrol alone or combined treatment. The length of intestinal villi was increased in response to antioxidants and reduced on doxorubicin. Antioxidant supplements effectively prevent bone deformities and mineralization defects, increase antioxidant response and reverse doxorubicin-induced effects on bone anomalies, mineralization, and oxidative stress. A combined treatment of doxorubicin and antioxidants was beneficial in fish larvae and showed the potential for use in preventing Doxorubicin-induced bone impairment.