Contested Paradigm in Raising Zebrafish (Danio rerio)

Abstract

The current body of work on rearing larval/juvenile zebrafish is based on (1) utilization of freshwater and (2) diurnal light/dark cycle, (3) provision of live feed at modest density, and (4) culture in high visibility environment. We challenged these rearing approaches by maintaining zebrafish under constant light for 46-48 days (days postfertilization [dpf]), while securing continuous feeding in high turbidity and saline (1.8-2.1 parts per thousand) environment for the experiment's duration, allowing 24 h feeding/growth of fish from first exogenous feeding to maturation. There was no evidence of negative effects on zebrafish larvae behavior, growth, survival, and life cycle duration at constant illumination when food was continuously available. Zebrafish were stocked at high initial density (100 larvae/L) in a static system and fed high densities of rotifers (Brachionus plicatilis) (200-400/mL) from 6 to 12 dpf. Fish density was then reduced by 50% and two diet treatments, live rotifers or brine shrimp (Artemia) nauplii (10/mL), followed. Fish were reared on these two diets until first maturation. Performance of adult zebrafish fed live rotifer followed by Artemia nauplii diet was the highest recorded in the literature after 42 dpf, 250 ± 29 (males) and 430 ± 5 mg (females). Use of these rearing conditions, during the entire life cycle, until reproduction, resulted in the shortest ever recorded generation time (from egg to egg) of 43-45 dpf and fertilization rate (1 dpf) of 80.3%-94%.

Why are triploid zebrafish all male?

“…Embryos were incubated in mesh‐bottom baskets suspended in a recirculating system (Pentair Aquatic Ecosystems, Apopka, FL) maintained at 28.5 ± 0.5°C. At 5 dpf, the larvae were stocked into static water tanks and raised according to Delomas () and based on the method developed by Dabrowski and Miller (). Briefly, the fish were maintained at 28.5 ± 0.5°C in low‐salinity (3 ppt) and mildly turbid (3–10 NTU, maintained with Nannochloropsis algae paste) water under a 24L:0D photoperiod until 21 dpf in Experiment 1 (28 dpf in Experiment 2).…”

Can intestinal absorption of dietary protein be improved through early exposure to plant-based diet?

“…Water in the system was constantly filtered and recirculated using a mat filter, UV light, a carbon filter, and biofiltration. The average water temperature was 27.1 ± 0.2˚C, the pH was 7.28 ± 0.72, and the salinity was kept between 1 and 3 ppt (higher during the first feeding to prolong the viability of the live food [21]). The photoperiod consisted of 14 hours of darkness and 10 hours of light, with the overhead lights on 8:00-18:00.…”

The Use of Dipeptide Supplementation as a Means of Mitigating the Negative Effects of Dietary Soybean Meal on Zebrafish Danio rerio

“…Water in the system was constantly filtered and recirculated using a mat filter, UV light, a carbon filter, and biofiltration. The average water temperature was 27.1 ± 0.2°C, the pH was 7.01 ± 0.23, and the salinity was kept between 1 and 3 ppt (higher during the first feeding to prolong the viability of the live food [25]. The photoperiod consisted of 14 hours of darkness and 10 hours of light, with the overhead illumination from 08:00-18:00.…”