Can sea urchins benefit from an artificial diet? Physiological and histological assessment for echinoculture feasibility evaluation

Abstract

In the Mediterranean sea, since the time of ancient Greece, the sea urchin Paracentrotus lividus has been considered a delicacy, and as a consequence, the market demand has increased since the early 1970s, significantly causing a depletion of wild stock. For this reason, the interest in breeding sea urchins has widened over the last two decades and several formulated diets were developed. In order to identify a low-cost diet, which is able to promote both the maintenance and the gonadal growth of organisms in recirculating aquaculture system (RAS), we evaluated the food intake of three different diets: the first composed of macroalgae naturally present in the sea urchins collection site, a second diet based on maize and spinach and finally a diet based on pellet normally used in aquaculture. The results presented in this study demonstrated the good feasibility of a low-cost and easy-tostandardize diet, such as that based on maize and spinach, in rearing vulnerable species such as P. lividus in RAS.

Effect of three diets on the gametogenic development and fatty acid profile of Paracentrotus lividus (Lamarck, 1816) gonads

“…Therefore, it was necessary to establish a sexual synchronization of the captured animals, in order to assess the influence of the experimental diets in the gametogenic development of their gonads. For this purpose, sea urchins were starved for 30 days, at a temperature of 16°C and salinity of 37 (Fabbrocini et al, ; Sartori & Gaion, ). Subsequently, sea urchins were randomly assigned in three recirculating aquaculture systems (RAS), each one composed by three tanks of 60 L, with aeration.…”

“…Despite this, the rearing methods for sea urchins' aquaculture are not well‐established in the European countries, in contrast to other echinoid species worldwide. In an attempt to get ahead in this field, the number of studies on aquaculture and nutrition of sea urchins has grown exponentially in the last decade (Carboni, ; Carboni, Hughes, Atack, Tocher, & Migaud, ; Fabbrocini, Volpe, Coccia, D'Adamo, & Paolucci, ; Fabbrocini et al, ; James & Siikavuopio, ; Kelly & Chamberlain, ; Parisi et al, ; Prato, Chiantore, et al, ; Prato, Fanelli, et al, ; Sartori & Gaion, ; Sartori, Pellegrini, Macchia, & Gaion, ; Silva, ; Vizzini, Miccichè, Vaccaro, & Mazzola, ; Vizzini, Visconti, Vaccaro, & Mazzola, ; Zupo, Glaviano, & Paolucci, ).…”

“…Many alternative feed sources have been studied to promote gonadal growth and to manipulate the gametogenic cycle for obtaining a desirable development stage. In particular, maize and spinach have been described as promising alternative diet sources (Basuyaux & Blin, ; da Rosa Repolho, Costa, de Jesus Luis, & de Matos Gago, ; Luis, Delgado, & Gago, ; Sartori & Gaion, ; Sartori et al, ; Sartori, Scuderi, Sansone, & Gaion, ; Silva, ). However, the formulation of a diet that can increase the size, enhance the nutritional value and the organoleptic characteristics of P. lividus gonads has not been fully achieved.…”

“…Therefore, the sea urchins need to be sexually synchronized and their gonads must be in a specific stage of gametogenesis, in order to ensure a continuous production to supply the market demand for this product (Spirlet et al, ). It is currently thought that it is possible to control the reproductive cycle of sea urchins, using different water quality parameters and feed sources (Fabbrocini et al, , ; Sartori & Gaion, ; Spirlet, Grosjean, & Jangoux, , ; Walker, Harrington, Lesser, & Fagerberg, ; Walker, McGinn, Harrington, & Lesser, ). To create the appropriate diet for these purposes, it is necessary to understand the nutritional profile of sea urchins throughout their gametogenic development.…”

Morphological and Biochemical Profiles of the Gonadal Cycle in the Sea Urchin Paracentrotus lividus: Wild Type vs. Bred

“…This diet also shows a low mortality rate, about 20%, compared to the other diets that bring a maximum value of mortality as 30% (data not shown). Other researchers have described the benefit of artificial diets over the use of maize: Repolho assessed the effect of captive brood-stock diet on fertilization and endotrophic larvae development of P. lividus obtained for maize diet [59,60]. Histological analysis revealed a good quality of gonadal tissue in all cages, but compared to the wild animals, the gonadal cycle seems to be slowed down by 1-2 months, despite the biochemical profile of the gonads that does not reveal alterations in the amount of the different components.…”