The contribution of diatoms to bioflocs lipid content and the performance of juvenileLitopenaeus vannamei(Boone, 1931) in a BFT culture system

Abstract

This study aimed to evaluate the contribution of three diatom species on the lipid content of bioflocs, their permanence on the bioflocs and influence on the growth performance of juvenile shrimps. Juveniles of Litopenaeus vannamei were reared (30 days; three replicates per treatment) in biofloc systems inoculated with diatoms Amphora coffeaeformis (A), Cylindrotheca closterium (C), Conticribra weissflogii (W), or biofloc only (BF, chlorophycean rich). Water quality parameters were monitored daily and the microbiota on days 1, 10, 20 and 30. The lipid content and fatty acid profiles of bioflocs were analyzed at the end of the experiment. Shrimp survival rate (99%) at treatment A was significantly higher than at BF. The bioflocs in A treatment presented the highest lipid content, differing significantly from BF and W. The content of EPA (20:5) (n-3) was significantly higher in A and lower in BF, while linoleic acid (18:2) (n-6) was significantly higher in BF. The results indicate that high cell density of diatoms can be successfully maintained with silicate addition in biofloc systems and that the pennate A. coffeaeformis and the centric C. weissflogii are potentially better suited than the pennate C. closterium as food supplements for shrimp diets in biofloc nurseries system.

Effects of addition ofNaviculasp. (diatom) in different densities to postlarvae of shrimpLitopenaeus vannameireared in a BFT system: Growth, survival, productivity and fatty acid profile

“…In this study, due to daily alkalinity correction, no decrease in pH levels was observed during the experimental period. In relation to P-orthophosphate, the addition of the diatoms did not reduce this nutrient, similar to what was observed with Navicula sp., Amphora coffeaeformis, Cylindrotheca closterium and Conticribra weissflogii addition in BFT systems Martins, Odebrecht, Jensen, D'Oca, & Wasielesky, 2016). In relation to P-orthophosphate, the addition of the diatoms did not reduce this nutrient, similar to what was observed with Navicula sp., Amphora coffeaeformis, Cylindrotheca closterium and Conticribra weissflogii addition in BFT systems Martins, Odebrecht, Jensen, D'Oca, & Wasielesky, 2016).…”

Effect of the addition of diatoms (Naviculaspp.) and rotifers (Brachionus plicatilis) on water quality and growth of theLitopenaeus vannameipostlarvae reared in a biofloc system

“…Campaña‐Torres, Martínez‐Córdova, Villarreal‐Colmenares, Hernández‐López, Ezquerra‐Brauer and Cortés‐Jacinto () and Martins et al . () observed no influence on orthophosphate levels with plankton addition. In our study, a lower C:N ration was used (12:1) thus favouring a higher light penetration and microalgae uptake.…”

“…; Martins et al . ). The microbial community present in biofloc systems significantly improves weight gain and FCR of shrimp, thus potentially reducing the feed cost associated with shrimp production (Avnimelech ).…”

“…Higher concentrations of nitrate in a biofloc system with microalgae addition, as compared to nitrite and total ammonia nitrogen, were also observed by Martins et al . (), because heterotrophic and nitrifying bacteria are the main factors responsible for the transformation of total ammonia nitrogen and nitrite in a biofloc system (Castillo‐Soriano, Ibarra‐Junquera, Escalante‐Minakata, Mendoza‐Cano, Ornelas‐Paz, Almanza‐Ramírez & Meyer‐Willerer ). The alkalinity and pH levels in the culture water were within the range recommended for biofloc shrimp culture (Furtado, Poersch & Wasielesky ).…”

Innovative protein sources in shrimp (Litopenaeus vannamei) feeding

“…Martins et al . () pointed out that the microalgae diatoms developed in the biofloc can provide essential fatty acids (especially EPA and linoleic) to shrimp.…”