The effect of a formulated feed on the body growth and gonads quality of purple sea urchin (Paracentrotus lividus) aquaculture produced

Abstract

Sea urchin gonads are a prized gourmet product in many areas of the globe, and wild populations are threatened by increasing demand, making this species a very desirable product in aquaculture. Due to the unique needs of each stage of the life cycle, a viable food protocol that seeks to satisfy each stage while optimizing production profitability is required. The objective of this work was to test a formulated feed for sea urchins, through the analysis of somatic growth, gonad development and their fatty acid profile. These results were compared with sea urchins fed natural food (Ulva spp.) At the end of the trial Paracentrotus lividus juveniles fed inert diet had higher total wet weight gain, total specific growth rate, and gonadosomatic index than those fed with macroalgae. However, histological observations did not reveal differences in the maturation state of the gonads. In comparison to sea urchins fed fresh Ulva spp., inert diet showed higher total wet weight gain and higher total specific growth rate. Fatty acid contents of the gonads of each treatment were found to be similar. The DHA levels in the gonads of sea-urchins fed the formulated feed were significantly higher. It was possible to record the biosynthesis activity of some fatty acids such as 20:4 ω 6, 16:4 ω 3, and 20:3 ω 3. It was found that the presence of some essential fatty acids, such as DHA and EPA, in the gonads is only dependent on the food profile. The addition of a DHA-rich ingredient in the formulated feed may have been preponderant in the constitution and development of the sea-urchins’ gonads.

Influence of Feeding and Temperature and Photoperiod Manipulation on Purple Sea Urchin (<i>Paracentrotus lividus</i>) Gonad Development

“…and a food formulated for sea urchins. The choice of these two diets comes from previous knowledge of their potential influence on gonad development [18].…”

“…Analyses of its fatty acid profile showed that the inert food had a higher content of the three types of fatty acids: saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA). The inert food had much higher levels of 22:6 ω3 (DHA) than the macroalgae, due to the enrichment of microalgae biomass (Schizochytrium), and a high content of this fatty acid was then found in the gonads of the sea urchins fed this food, showing the close relationship between the food supplied and the gonads [18].…”

Histological Evaluation of Purple Sea Urchin (Paracentrotus lividus) Gonads: Influence of Temperature, Photoperiod Regimes, and Diets

“…and a feed formulated for sea urchins. The choice of these two diets comes from previous knowledge of their potential influence on gonad development [18].…”

“…The inert diet (If) consisted of pellets formulated and produced by the company SPAROS, R&D (Olhão, Portugal), specifically for sea urchins. The nutritional characteristics are described in Araújo et al [18]. The sea urchins were fed once every 3-4 days based on a daily consumption for each urchin of 0.40 g of Ulva spp.…”

“…For this reason, two different seasonal periods were produced by adjusting the temperature and photoperiod. Additionally, two diets were tested: an inert feed formulated for sea urchins [18] and a natural food (the macroalga Ulva spp. ).…”