Intensive production of the harpacticoid copepod Tigriopus californicus in a zero-effluent ‘green water’ bioreactor

Abstract

Aquaculture is looking for substitutes for fishmeal and fish oil to maintain its continued growth. Zooplankton is the most nutritious option, but its controlled mass production has not yet been achieved. In this context, we have developed a monoalgal ‘green water’ closed-loop bioreactor with the microalgae Tetraselmis chui that continuously produced the harpacticoid copepod Tigriopus californicus. During 145 days of operation, the 2.2 m3 bioreactor produced 3.9 kg (wet weight) of Tigriopus with (dry weight) 0.79 ± 0.29% eicosapentaenoic acid (EPA), 0.82 ± 0.26% docosahexaenoic acid (DHA), 1.89 ± 0,60% 3S,3’S-astaxanthin and an essential amino acid index (EAAI) of 97% for juvenile Atlantic salmon. The reactor kept the pH stable over the operation time (pH 8.81 ± 0.40 in the algae phase and pH 8.22 ± 2.96 in the zooplankton phase), while constantly removed nitrate (322.6 mg L−1) and phosphate (20.4 mg L−1) from the water. As a result of the stable pH and nutrient removal, the bioreactor achieved zero effluent discharges. The upscaling of monoalgal, closed-loop ‘green water’ bioreactors could help standardize zooplankton mass production to supply the aquafeeds industry.

Mitonuclear effects on sex ratio persist across generations in interpopulation hybrids

“…In this study, body length and total protein content of T. californicus were uncorrelated ( R = 0.042, p = 0.7, method = Pearson; electronic supplementary material, figure S4) indicating that length-specific metabolic rates do not effectively account for size variation. We therefore normalized metabolic rates to total protein, which constitutes the largest fraction of biochemical content in T. californicus 61 and is proportional to respiring biomass.…”

Iron Fertilization Can Enhance the Mass Production of Copepod, Pseudodiaptomus annandalei, for Fish Aquaculture

“…Access to a reliable supply of copepods on a commercial scale has been a bottleneck faced by aquaculturists hoping to use copepods in their operations on a daily basis. To overcome this shortfall, several methods, as well as specialized equipment for the large-scale production of copepods, have been devised [ 18 , 25 , 67 , 68 ]. For example, Prado-Cabrero, Herena-Garcia, and Nolan [ 68 ] designed a monoalgal bioreactor that uses the microalga Tetraselmis chui to continuously produce the harpacticoid copepod Tigriopus californicus [ 68 ].…”

“…To overcome this shortfall, several methods, as well as specialized equipment for the large-scale production of copepods, have been devised [ 18 , 25 , 67 , 68 ]. For example, Prado-Cabrero, Herena-Garcia, and Nolan [ 68 ] designed a monoalgal bioreactor that uses the microalga Tetraselmis chui to continuously produce the harpacticoid copepod Tigriopus californicus [ 68 ]. Sarkisian, Lemus, Apeitos, Blaylock, and Saillant [ 67 ] developed an indoor batch-culture system for intensive production of the calanoid copepod A. tonsa , featuring integrated grow-out and egg-production units that can produce nauplii daily.…”