Effect of rearing temperature in the growth of hatchery reared juveniles of the sea cucumber Holothuria arguinensis (Koehler & Vaney, 1906)

• Published in: Aquaculture Vol. 562; p. 738809
• Main Authors: Madruga, A.S., Félix, P.M., Sousa, J., Azevedo e Silva, F., Brito, A.C., Mendes, S., Pombo, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2023
• Subjects: Allometric coefficient; Aquaculture; Condition factor; Echinoderm; Length; Weight; Allometric coefficient; Length; Condition factor; Weight; Echinoderm; Aquaculture
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/j.aquaculture.2022.738809

Since the early 1980's there has been an increase in sea cucumber harvest and trade, mainly due to Asiatic market pressure. In the Indo-Pacific regions, the collapse of various stocks of these echinoderms has already occurred due to overfishing. In Europe, sea cucumber exportation depends exclusively on wild stock harvesting, which has demonstrated to be an unsustainable method to supply the markets, as these species are highly susceptible to overfishing. To enable a sustainable development of this emerging market in Europe the need to develop aquaculture techniques for these animals becomes of the utmost importance. At the current early stages of development, the viability of sea cucumber aquaculture for temperate species depends on the optimization of the rearing conditions. As ectotherms, temperature proves to be one of the most relevant parameters that affects the growth of sea cucumbers, as it influences metabolism and energy management and, in turn, future rearing methods and aquaculture sites. Therefore, this study aimed to determine the influence of temperature on the growth of H. arguinensis juveniles. A group of 168 juveniles (3.25 g ± 0.21; 3.81 cm ± 0.31) were placed under four different temperature treatments 18, 20, 22 and 24 °C for 4 months. The highest length (1.45 cm ± 0.16) and weight (2.79 g ± 0.14) gain were recorded at 20 °C. Similarly, the 20 °C treatment also produced the highest values for specific growth rate (0.50%/day) and the daily body length rate (0.30%cm/day). All allometric coefficients showed negative allometry (b < 3), a growth strategy that accentuates with increasing size. This life-history trait shows a higher distance from isometry the more distance the animals are from their optimum stocking temperature. Hence, metrics like the Fulton condition factor (K) show an inadequacy for the assessment of sea cucumber's condition, because a higher relative length decreases the value of K. A rearing temperature of 20 °C resulted in the best growth overall considering all increments in length and weight, pointing towards this as the best rearing temperature for the temperate species, H. arguinensis. •Selected Holothuria arguinensis as a candidate for developing its aquaculture technology further.•Four possible temperatures based on its natural environment (18, 20, 22 and 24 °C) were identified.•Increased growth both in weight and length was found at 20 °C.•Pointing 20 °C as the best rearing temperature for H. arguinensis.