Effect of different dietary microalgae combinations on growth and survival of black-lip pearl oyster (Pinctada margaritifera) larvae and the feasibility of replacing microalgae with a dietary lipid emulsion

Abstract

A 10-day experiment was performed to examine different mono, binary and ternary dietary combinations on survival and growth of D-shaped and umbone black-lip pearl oyster, Pinctada margaritifera, larvae. The three tropical microalgae species were the flagellate Isochrysis galbana clone T. Iso (CS-177) and diatoms Chaetoceros calcitrans (CS-178) and Chaetoceros muelleri (CS-176) which were fed to D-shaped and umbone larvae at a density of 7000 and 14 000 cells mL À1 , respectively. A second experiment was performed to investigate the feasibility of replacing T. Iso with a lipid emulsion for both D-shaped and umbone larvae for 10 and 12 days, respectively. The treatments included only T. Iso, unfed and lipid emulsion to substitute T. Iso at levels of 10% (LIP10), 30% (LIP30) and 100% (LIP100). In the first experiment, results showed that a monospecific diet of T. Iso led to significantly higher (P < 0.05) survival and growth of D-shaped larvae than all the other treatments. Meanwhile, D-shaped larval survival was significantly lower when only fed C. calcitrans as well as growth for those fed C. calcitrans or in combination with C. muelleri. However, for umbone larvae, survival and growth were significantly higher when fed a binary combination of T. Iso and C. muelleri or the ternary combination of T. Iso, C. muelleri and C. calcitrans compared with all other treatments. For the second experiment, results showed that with increasing lipid emulsion replacement, survival of both D-shaped and umbone larvae significantly decreased (P < 0.05); however, the LIP100 treatment was not significantly different (P > 0.05) from the unfed treatment. For D-shaped larvae, no significant growth difference was detected (P > 0.05) between the T. Iso and LIP10 fed treatments while for umbone larvae, the T. Iso, LIP10 and LIP30 were not significantly different (P > 005). These results indicate that microalgae combinations appear more necessary for later staged P. margaritifera larvae. In addition, the use of a lipid emulsion appeared to provide some nutrition to the larvae, although more research should be conducted to improve the use of such replacements.

Freshwater microalgae (Schizochytrium sp.) as a substitute to fish oil for shrimp feed

“…An imbalance in these fatty acids in other microalgae meals was implicated as a potential reason for lower growth in the shrimp, Litopenaeus schmitti 22 . This is consistent with the concept that a monoculture of microalgae is inferior compared to the use of microalgae mixtures when compensating for any potential nutritional deficiencies to various aquatic animals 23,24 . In this study, L. vannamei appeared to utilize Schizochytrium sp.…”

Quantifying photosynthetic performance of phytoplankton based on photosynthesis–irradiance response models

“…galbana and D. salina are applied world-wide to generate biofuels due to their rich lipids (lipid levels between 23 and 55% by weight of dry biomass), and they are also commonly cultivated with P. subcordiformis (lipid levels between 20% and 30% by weight of dry biomass) for aquaculture in China, Japan, Australia, and southeast Asia [14,49]. To meet nutritional requirements, mixed cultures of two or more species of phytoplankton are often fed to larvae in seed farming of aquatic products [50]. It is critical that the photosynthetic productivity of each strain reach as high as possible during production.…”

Effect of dietarySchizochytriumsp. oil as an n‐3 long‐chain polyunsaturated fatty acid source on growth performance, lipid metabolism and antioxidant status in juvenile grass carp (Ctenopharyngodon idellus): A comparative study with fish oil

“…(2019) indicated there was no obvious difference on the FCR or growth in shrimp fed Sc meal compared with fish oil, and when shrimp were fed with fish oil‐free diet there were no indications of feed rejection. Furthermore, it was worth noting that the oil from Sc had high proportion of DHA, low proportion of EPA, some studies have shown that the imbalance between DHA and EPA in microalgae may be a potential cause of the decline in the growth performance of aquatic animals (Ehteshami, Romano, Ramezani Fard, & Hoseinzadeh Sahafi, 2017; Jamali, Ahmadifard, & Abdollahi, 2015). However, Sc oil could promote the growth of grass carp in this study, which may be related to the requirement of grass carp for DHA was higher than EPA (unpublished) and the mechanism of selectively retaining DHA of grass carp (Lei, Ji, Zhang, & Li, 2016).…”