Lipid metabolism of sea urchin Paracentrotus lividus in two contrasting natural habitats

Abstract

Sea urchins Paracentrotus lividus were harvested monthly from April 2015 to March 2016 from two sites in Sardinia (Italy). The two sites, a Posidonia oceanica meadow and a rocky bottom habitat, were naturally characterized by different food sources and availability, being mainly populated by the sea grass Posidonia oceanica and the brown algae Halopteris scoparia, respectively. Total lipids showed a minimum during winter in mature gonads, and a maximum in the summer (recovery stage). Fatty acid (FA) profiles of gut contents and gonads differed from those of the most available food sources. Levels of C18:3 (n-3) (ALA) discriminated samples from the two sites. Despite the very low amounts of C20:5 (n-3) (EPA) and C20:4 (n-6) (ARA) in P. oceanica, the main FA in gonads and gut contents were EPA and ARA in both sites. Increase in green algae intake prior to gametogenesis, especially C. cylindracea, likely affected EPA and ARA levels in gonads. The results show that P. lividus is able to concentrate lipids in gut contents and also to selectively store EPA, ARA and their precursors ALA and 18:2 (n-6) (LA). Moreover, bioconversion of ALA to EPA and of LA to ARA in P. lividus is suggested.

Spatial Succession Underlies Microbial Contribution to Food Digestion in the Gut of an Algivorous Sea Urchin

“…These regions offer the resident bacteria more determinate niches with specific environmental conditions regarding the abiotic parameters and available nutrients. Previous studies on sea urchins (i.e., Echinocardium cordatum , Paracentrotus lividus , and Spatangus purpureus ) revealed the stomach as an extreme environment with a relatively acidic pH, low oxygen, high carbon dioxide, and elevated concentrations of short-chain fatty acids (SCFAs) ( 11 , 21 , 22 ). Bacterial fermentation has been proposed to increase SCFAs and reduce pH levels, actions which are essential in breaking down food particles in this region ( 11 , 20 ).…”

Evidence of microplastic-mediated transfer of PCB-153 to sea urchin tissues using radiotracers

“…It is also encouraged for future work to continue to express the PCB concentrations based on the total lipids content given the lipophilicity of the contaminants. In addition, the PCB concentrations expressed on a total lipid content basis are particularly valuable information given the seasonal transferability of lipids, and their associated contaminants, across the body parts observed for various organisms including for Paracentrotus lividus (Fernandez, 1998;Rocha et al, 2019;Anedda et al, 2021). In general for Paracentrotus lividus, the highest lipids content corresponds to a prevalence of recovery gametogenic stage (accumulation of reserves during the summer season), and the lowest lipids content in gonads corresponds to a high occurrence of mature gametogenic stages (reserves used for gamete development during the winter season) (Fernandez, 1998;Anedda et al, 2021).…”

“…In addition, the PCB concentrations expressed on a total lipid content basis are particularly valuable information given the seasonal transferability of lipids, and their associated contaminants, across the body parts observed for various organisms including for Paracentrotus lividus (Fernandez, 1998;Rocha et al, 2019;Anedda et al, 2021). In general for Paracentrotus lividus, the highest lipids content corresponds to a prevalence of recovery gametogenic stage (accumulation of reserves during the summer season), and the lowest lipids content in gonads corresponds to a high occurrence of mature gametogenic stages (reserves used for gamete development during the winter season) (Fernandez, 1998;Anedda et al, 2021). In order to investigate the seasonality of the MP-mediated transfer of PCB, further work mimicking the present study while using adult P. lividus in a different gonadic maturation stage than ours is required.…”

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

“…Candeias-Mendes et al (2020) also found high levels of linoleic acid (18:2 ω6) in the gonads of sea urchins fed with maize and Ulva spp., these values being much higher than the percentage obtained in this work. InAnedda et al (2021) the values of this fatty acid were lower, not reaching 5% of total fatty acids.…”