Microalgal Diet Influences the Nutritive Quality and Reproductive Investment of the Cyclopoid Copepod Paracyclopina nana

Abstract

Copepods represent an interesting alternative or a complement live food to brine shrimps and rotifers commonly used in aquaculture. They constitute the natural prey of many fish species and therefore do not require a potential nutritional enrichment. But an optimization of the microalgal diets used to feed copepods is essential to improve their mass culture. This study examined the effects of seven microalgal diets, namely single-species diets of Rhodomonas salina (R), Tisochrysis lutea (T), and Pavlova lutheri (=Diacronema lutheri) (P), two-species diets (R + T, T + P, and R + P), and a three-species diet (R + T + P), on the fatty acid and monosaccharide composition of the cyclopoid copepod Paracyclopina nana as well as its reproductive investment. Experiments were run during 15 days in 10-L beakers; starting with nauplii collected from a large 300-L batch culture. Copepods fatty acid contents were studied, particularly the relative amounts of docosahexaenoic acid (DHA) and eicosa-pentaenoic acid (EPA). The R + T, R, and T diets induced the highest total fatty acid amount in copepods. R + T and R also generated the lowest DHA/EPA ratios in copepods due to high EPA contents. The highest value of total monosaccharides was found in copepods fed with R + T + P. Diets R + T and R induced the greatest prosome volumes and clutch volumes in ovigerous females. Both prosome volume and clutch volume in P. nana ovigerous females were correlated to the individual EPA amount. The results demonstrated that all diets including R. salina enhanced the productivity of P. nana in mass culture, particularly when combined with T. lutea. R. salina, and T. lutea induced complementary fatty acid and monosaccharide profiles, confirming that R + T represents the best microalgae combination for productive culture of P. nana. Conversely, P. lutheri did not enhance the nutritional profile nor the fecundity of P. nana in the culture. This study is the first to demonstrate that R. salina is a suitable microalga for productive mass culture of P. nana for use as live food in aquaculture.

Acute and chronic toxicity assessments of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) on the calanoid copepod Acartia clausi: Effects on survival, development, sex-ratio and reproduction

“…sp.) was used to feed A. clausi as monoalgal diets do not meet the nutritional requirement of copepods namely Acartia sp (Zhang et al, 2013;Dayras et al, 2021). The suitability of these algae in terms of nutritive value for crustacean species has been previously confirmed (Støttrup and Jensen, 1990;Alvarez-González et al, 2001;Payne and Rippingale, 2001).…”

Influence of Microalgae Diets on the Biological and Growth Parameters of Oithona nana (Copepoda: Cyclopoida)

“…Our data showed no difference in body size between O. nana that were fed single and mixed algae diets. This is not the case in other cyclopoids, such as Paracyclopina nana , which were found to have larger body sizes when fed mixed diets [ 91 ]. The body size range for each stage of O. nana recorded in this study corresponds to the sizes reported in natural and cultured conditions by other authors, indicated in Table 4 .…”

Impacts of Fortifying Nile Tilapia (Oreochromis niloticus) Diet with Different Strains of Microalgae on Its Performance, Fillet Quality and Disease Resistance to Aeromonas hydrophila Considering the Interplay between Antioxidant and Inflammatory Response

“…Our findings of beneficial impacts of including NSS microalgae mixture in Nile tilapia diets on deposition of DHA and EPA (two important omega-3 PUFAs) are also consistent with a previous observation [ 75 ], where higher PUFAs were observed with increasing the supplementation level of Schizochytrium species enriched with DHA fatty acid. Moreover, incorporation of microalgae enriched with DHA and EPA increased their contents in copepods [ 76 ]. Additionally, feeding of sea bream on diets enriched with microalgae blends including Nannochloropsis , oculata , and Schizocthytrium species displayed an increased long-chain n-3-PUFAs, DHA, and EPA levels [ 77 ].…”