Assessing the impacts of several algae-based diets on cultured European abalone (Haliotis tuberculata)

Abstract

The effects of different algal diets on the mortality, apparent ingestion, weight, length and conversion rates of the European abalone (Haliotis tuberculata) maintained in a semi-closed seawater system throughout the year were compared. Various combinations of red algae (Palmaria palmata, Ceramium rubrum and Chondrus crispus cultured or harvested from the natural environment, as well as Porphyra spp. collected), brown algae (Laminaria digitata) and green algae (fresh or frozen Ulva intestinalis) were tested. The results showed that P. palmata, C. rubrum and U. intestinalis administered alone were associated with significantly higher weight growth rates than the other species of algae tested. However, some combinations of algae (i.e. different proportions of L. digitata in association with P. palmata) were more favorable for weight increase when compared with the expected rates calculated for the diet based on L. digitata alone. Limiting the amount of any of these foods substantially reduced the conversion rate. Seasonal trends were apparent in both weight increase and food conversion rates, with the result that growth in weight on a diet of L. digitata was fastest in summer. Growth on P. palmata was faster in each season, and reached a maximum in early spring. The data collected allowed us to model weight increase and month-to-month food conversion rates for a diet based on P. palmata and L. digitata. The data obtained in this study were coupled with data regarding the availability of algae during the year, enabling us to suggest an optimal diet for each of the four seasons. Finally, the effects of different algae diets were investigated on hemocyte parameters, and the result suggested that P. palmata would reinforce the immune system of abalone.

Effects on Growth of Juvenile Abalones Haliotis tuberculata Under Chronic Exposition to Metals Released from the Dissolution of an Aluminium-Based Galvanic Anode

“…Our results of the different parameters reflecting the growth and nutrition of young abalones under control conditions are in agreement with values found in a previous study focusing on the importance of Palmaria palmata in the diet of H. tuberculata (Basuyaux et al 2018). As shown in the results, all parameters were significantly affected from 494.9 µg L −1 of Al.…”

Impact of nine macroalgal diets on growth and initial reproductive investment in juvenile abalone Haliotis tuberculata

“…gave moderate growth performances while U. lactuca and stipes of L. hyperborea presented the lowest growth performances. Previous studies on H. tuberculata have shown that diets based on P. palmata produced better growth rates than most of the algae found in Europe (Mercer et al, 1993;Mai et al, 1996;Viera et al, 2015;Basuyaux et al, 2018). In addition, the high nutritional value of P. palmata has been reported for other abalone species such as H.…”

“…Only a few studies directly compared the effects of different macroalgal diets on growth focusing on their seasonal composition changes on the long term (Basuyaux et al, 2018) and…”

“…order to prevent depletion of the algal resources, a mixed diet seems an optimal solution for European abalone farms, with good growth performance as tested by Basuyaux et al (2018).…”

Comparative Tissue Responses of Marine Mollusks on Seasonal Changes in the Northern Adriatic Sea

“…The oscillation in seawater seasonal properties might also negatively affect physiology, stress response and, ultimately, the survival of scallops in the Northern Adriatic [15,16]. In mollusks, the cellular immune system is composed of hemocytes and their phagocytic immune response is the first line of defense, but it is also equipped with an array of other tissue defense mechanisms [17]. The tissue responses to seasonal variations in green ormers and Mediterranean scallops in the Northern Adriatic have not been reported.…”