Fish Larviculture Research Articles

An Overview of the Freshwater Cladoceran Daphnia magna (Straus, 1820) and Its Application in Fish Larviculture

Over the last three decades, aquaculture has become increasingly important, leading to the commercial viability of various shellfish and finfish species. The production of live feed is gaining popularity as a way to enhance the nutritional quality of species raised in aquaculture. Daphnia is a type of small crustacean belonging to the Brachiopoda family, commonly found in freshwater environments. Daphnia spp. serves as an excellent natural food source for tropical fish fry and has emerged as an alternative to traditional fish feeds. Utilizing Daphnia in aquaculture offers benefits such as low cost and ease of cultivation. This study addresses the identification of Daphnia, its reproduction and life cycle, nutritional value, significance in aquaculture, and methods of cultivation.

Sludge from Arapaima Gigas Culture as an Alternative Culture Medium for Lipid Production in Nannochloropsis Sp

Objective: The objective of this work was to evaluate the use of sludge generated during the culture of Arapaima gigas as an alternative medium for Nannochloropsis sp. Theoretical Framework: Microalgae are photosynthetic micro-organisms with the ability to transform organic waste or effluents into valuable biomass. They are currently of great interest for their use in the food and pharmaceutical industry. Nannochloropsis sp. is a valuable microalga due to its excellent lipid profile. Method: The sludge used was collected from A. gigas culture ponds at the CITE Acuícola Pesquero Ahuashiyacu (Tarapoto-Peru). An aqueous extract of sludge (EAL) was obtained from the sample by a thermal procedure, which was dosed into the cultures at concentrations of 100, 150 and 200 mL/L. The experimental units followed the traditional batch culture arrangement under laboratory conditions. Guillard F/2 medium was used as control treatment. The characterisation of metals in the medium was performed by coupled plasma induction (ICP) and the determination of ammonium and nitrite by colorimetric tests. In addition, population density, productivity and total lipid content were estimated. Results and Discussion: Chemical analyses revealed high concentrations of calcium, sodium, magnesium, iron, potassium, phosphorus, ammonium and nitrite (655, 648, 283, 67, 32, 17, 1.5, and 10 ppm, respectively). Likewise, the best growth (3590.00 ± 91.24 x 104 cells/mL) and productivity (0.69 ± 0.01 g/L) was obtained with 200 mL/L of EAL, presenting significant statistical differences (p < 0.05) with respect to the other treatments. In contrast, the highest lipid production (29.67 ± 1.53 %) was observed in the control treatment, far exceeding the EAL cultures; however, no significant statistical difference was observed between EAL treatments. Research Implications: These results demonstrate the feasibility of using EAL as an alternative medium for the production of Nannochloropsis sp. with a positive environmental and economic impact on the production of A. gigas. Originality/Value: The use of sludge generated in fish culture, in particular A. Gigas, has not been reported previously. In this study, we demonstrate for the first time the feasibility of using this sludge in the culture of the microalga Nannochloropsis sp. which also has a high potential for use in fish larviculture.

Studies on development of microalgae omega-3 fatty acids transfer system in fish larviculture

Studies on development of microalgae omega-3 fatty acids transfer system in fish larviculture

Antimicrobial Activity, Genetic Relatedness, and Safety Assessment of Potential Probiotic Lactic Acid Bacteria Isolated from a Rearing Tank of Rotifers (Brachionus plicatilis) Used as Live Feed in Fish Larviculture.

Aquaculture is a rapidly expanding agri-food industry that faces substantial economic losses due to infectious disease outbreaks, such as bacterial infections. These outbreaks cause disruptions and high mortalities at various stages of the rearing process, especially in the larval stages. Probiotic bacteria are emerging as promising and sustainable alternative or complementary strategies to vaccination and the use of antibiotics in aquaculture. In this study, potential probiotic candidates for larviculture were isolated from a rotifer-rearing tank used as the first live feed for turbot larvae. Two Lacticaseibacillus paracasei and two Lactiplantibacillus plantarum isolates were selected for further characterization due to their wide and strong antimicrobial activity against several ichthyopathogens, both Gram-positive and Gram-negative. An extensive in vitro safety assessment of these four isolates revealed the absence of harmful traits, such as acquired antimicrobial resistance and other virulence factors (i.e., hemolytic and gelatinase activities, bile salt deconjugation, and mucin degradation, as well as PCR detection of biogenic amine production). Moreover, Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR) analyses unveiled their genetic relatedness, revealing two divergent clusters within each species. To our knowledge, this work reports for the first time the isolation and characterization of Lactic Acid Bacteria (LAB) with potential use as probiotics in aquaculture from rotifer-rearing tanks, which have the potential to optimize turbot larviculture and to introduce novel microbial management approaches for a sustainable aquaculture.

Long-term effects of different concentrations of vinasse on growth and survival, reproductive and life span characteristics of Artemia franciscana (Kellogg, 1906) and Artemia parthenogenetica

ABSTRACT The larviculture of fish and shellfish is inevitably dependent on live feed such as Artemia, and one of the most critical issues in rearing Artemia is the food supply. Artemia franciscana and Artemia parthenogenetica were raised at two concentrations of vinasse (62.5 and 125 µl L−1). The control diet was algae + wheat bran. The results demonstrated significant differences in the survival of Artemia species grown in different concentrations of vinasse on diets (P < .05). However, no significant differences were observed in the length of 125 µl L−1 and 20% algae with the A. franciscana control (P > .05). The total length in A. parthenogenetica was significantly higher than those received in vinasse (P < .05). The percentage of encysted in A. franciscana and A. parthenogenetica that fed vinasse in any concentration showed significant differences (P < .05) but not for other reproductive and lifespan characteristics (P > .05).

Larviculture of Brycon amazonicus under Different Food and Farming Systems

Freshwater fish larviculture techniques still have deficiencies in cultivation and feeding. In this study, we evaluated experimentally different cultivation and feeding systems in the Brycon amazonicus (matrinxã) larviculture. Seven treatments with different live foods were used: T1 = a semi-intensive mesocosm system with green water; T2 = a clear water system containing Artemia sp. as food; T3 = a clear water system containing Dendrocephalus brasiliensis as food; T4 = a clear water system containing a combination of Artemia sp. and D. brasiliensis as food (a proportion of 1:1); T5, T6 and T7 were the same as T2, T3 and T4, respectively, but with a swimming exercise system. During the experiment, the water quality parameters were measured and maintained suitably for the cultures. The highest values of final weight (42.97 ± 2.58 mg) and specific growth rate (31.77 ± 0.60%) were observed in T5 (p &lt; 0.05). Regarding the nutritional composition, the larvae of B. amazonicus that were fed nauplii of D. brasiliensis had a better profile of amino acids and essential fatty acids than those fed other live foods. Therefore, nauplii of D. brasiliensis can be used as an adequately nutritional food for larvae of B. amazonicus.

IoT based system for monitoring dissolved oxygen and temperature in fish larviculture

IoT based system for monitoring dissolved oxygen and temperature in fish larviculture

Optimization of Artemia Feed Regimes for Larval Giant Kōkopu (Galaxias argenteus)

Optimizing the initial live feed is critical to success in fish larviculture in terms of both larval health and productivity. It is also vitally important due to the significant cost of provisioning live feeds. Glaxiids are high-value diadromous fish species found in parts of the Southern Hemisphere, which are wild-harvested and sold for human consumption in their larval form. In the emerging aquaculture of galaxiids, the live feed makes up a great proportion of the production cycle and is therefore a significant factor in achieving the economic viability of their production. In New Zealand, the endemic galaxiid species giant kōkopu (Galaxias argenteus) is considered suitable for aquaculture; however, little is known of their larval-feeding requirements. This study compares the growth performance and survival of giant kōkopu larvae over a four-week period when fed different proportions of first-molt Artemia nauplii (instar-I) and enriched, second-molt-onward Artemia (instar-II+) for different durations. The larvae in the treatment group which received the greatest proportion of Instar-I Artemia for the longest duration had the lowest mean wet weight and survival, leading to the production of the lowest total biomass of fish larvae when compared to the other feed treatments. The feed treatment that received only instar-II+ Artemia achieved an equally best total productivity. While the treatment fed a partial initial duration of mixed instar-I and instar-II+ Artemia achieved the same total productivity, the individual larvae were heavier and their body length was longer. The latter feed treatment appears to offer the best balance between the availability of feed particles in the optimum size range and a higher level of digestibility given that instar-I Artemia had higher levels of highly unsaturated fatty acids and polyunsaturated fatty acids.

Dietary Euterpe oleracea Essential Oil, the Amazon Açaí, as Feed Additive to Amazonian Ornamental Fish, during Post-Larvae Growing Stage: A Preliminary Study

The present study aimed to evaluate the growth performance, batch uniformity, and survival rate of the Amazonian ornamental fish Heros severus and Pterophyllum scalare during the post-larvae growing stage, fed with diets containing levels of Euterpe oleraceae essential oil (EOO) during 30 days. In the first experiment, 160 H. severus post-larvae were distributed in 16 aquariums (1 L), and in the second, 200 P. scalare post-larvae were randomly distributed in 20 aquariums (1 L). The experiments were carried out in a completely randomized design, with four treatments for H. severus (0.0%, 0.50%, 1.00%, and 2.00% of dietary EOO) and five treatments for P. scalare (0.0%, 0.5%, 1.0%, 2.0%, and 4.0% of dietary EOO), both with four replications and dietary EOO being included in replacing soybean oil. A quadratic effect (p &lt; 0.01) was observed for the final length, length gain, specific growth rate for length, final weight, weight gain, specific growth rate for weight, and batch uniformity for weight for both fish species. As for ornamental fish larviculture, survival rate and batch uniformity are the most important parameters to be considered. For P. scalare and H. severus post-larvae, the inclusion of dietary EOO was beneficial in up to 2.48% and 0.88%, respectively.

Comparison of Three Artificial Diets for the Larviculture of Giant Kōkopu (Galaxias argenteus)

The selection of artificial feed is critical to the success of larviculture of fin fish and requires knowledge of the varied species-specific dietary and nutritional requirements. With the emergence of commercial aquaculture of giant kōkopu, Galaxias argenteus, there is a need to understand the species-specific needs for artificial feeds in larviculture. Consequently, this study compares three commercial artificial dry feeds; Otohime, Artemac and O.range on the growth of recently weaned giant kōkopu. Larvae fed with Otohime outperformed both Artemac and O.range treatments by achieving the highest wet weight after 67 days, greater by at least 47% on average than both Artemac and O.range. These differences in larval performance are likely to be due to the higher protein:energy ratio and EPA content of Otohime. High DHA and ARA in the diets in absolute terms or in relation to EPA did not result in added benefit for growth performance. This study provides an important first step in identifying the nutritional needs of larval giant kōkopu which can assist in improving their commercial aquaculture production.

Improving the weaning of larval giant kōkopu, Galaxias argenteus: An emerging aquaculture species

AbstractUsing live feed in fish larviculture is more expensive and challenging than formulated feeds, incentivizing the early weaning of larvae. In New Zealand, the aquaculture of larval giant kōkopu, Galaxias argenteus, is being commercialized because of its high value and to supplement the wild fishery. As an emerging aquaculture species, inefficiencies remain in the production process, inhibiting financial viability. This study reports on the ability of these larvae to consume formulated larval diets across four ages (18, 21, 25, and 28 days after hatching, DAH) at each of the three daily feeding events (Morning, Midday, and Afternoon) during commercial production. At 18 DAH, little to no formulated feed was consumed at either of the three feeding events throughout the day. At 21 DAH, mean gut fullness increased and the number of fish with empty stomachs reduced by the end of the Morning and Afternoon feeding events. Both variables improved further for larvae at 25 and 28 DAH. Formulated feed consumption did not differ between larvae aged 25 and 28 DAH indicating that 3 days of feeding live feed could be removed from the feed regime. This change would save 13% on the cost of live feed; however, further research is required to determine the potential impacts on growth and survival.

Development of enriched Artemia and Moina in larviculture of fish and crustaceans: a review

Inconsistencies in the nutritional values of live food such as Artemia and Moina are well-known issues. The enrichment of live food is necessary to obtain the optimum nutrients needed for the growth, survival, and immune competence of fish and crustaceans' larvae. The enhanced growth and survival of fish and crustaceans' larvae are vital to continuous aquaculture production. However, enriched live food could be species-specific as various aquatic larval species may respond differently to the enrichment diets. The enrichment of Artemia and Moina as the "bags of nutrients" has been widely studied and involved various enrichment diets such as commercial diets containing essential fatty acids, highly unsaturated fatty acids, and vitamin C. The use of natural enrichment diets such as yeast, microalgae, and herbal extract, including the common name Chinese chaste tree leaf (Vitex negundo), is becoming popular in aquaculture nutritional development. These natural enrichment diets are more economical and environmentally friendly than commercial diets. The compositions of Artemia and Moina are both affected by the enrichment diets that they consumed, hence directly affecting the growth of the larvae that fed on them. Hence, this review highlights the development of enriched Artemia and Moina and their effects on the growth performance and the immune competence of fish and crustaceans' larvae.

Swimbladder non-inflation and its influence on larviculture of mandarin fish (Siniperca chuatsi)

Low occurrence of swimbladder inflation often leads to vertebral skeletal malformations and poor swimming ability, which exert numerous effects on growth, feeding, buoyancy regulation and survival rate of fish larvae. In the present study, 713 mandarin fish (Siniperca chuatsi) larvae samples ranging from 5 to 11 days post hatch (DPH) were collected to detect the rate of swimbladder inflation and calculate the body density of each sample. Swimbladder inflated fish larvae were increased with the development of DPH except 7 DPH, with 86.21% in 11 DPH whereas 27.59% in 5 DPH. Our results indicate that 5–11 DPH is the main stage for swimbladder inflation in mandarin fish larvae, following the onset of exogenous feeding. The body density of swimbladder inflated (SBI) fish larvae (0.983 ± 0.016 g/cm3) was lower than the swimbladder non-inflated (SBN) ones (1.023 ± 0.018 g/cm3), while SBI fish larvae were significant heavier (p < 0.05) than SBN group. These findings suggest that swimbladder non-inflation could significantly influenced the neutrally buoyancy maintained and live bait predation in mandarin fish. The research will contribute to understanding the influence of initial swimbladder inflation on larviculture of mandarin fish.

Selenium supplementation levels and sources in postlarvae Nile tilapia diet

Fish larviculture exert great influence in the subsequent phases, in which nutrition is a basic prerequisite for success. Therefore, when it is in an intensified production system, it promotes the limitation of some minerals, making it necessary to supplement selenium in diets for post-larvae. The objective of this study was to evaluate selenium levels and sources in post-larvae Nile tilapia diets on muscle performance and histology. A total of 1,260 post-larvae with an initial average weight of 0.010 g were used, distributed in a completely randomized design in a factorial scheme with four supplementation levels (0.6; 0.9; 1.2 and 1.5 mg of Se/Kg) and two sources (sodium selenite and selenium yeast), plus the negative control, with 35 post-larvae Nile tilapia used per experimental unit. The physical-chemical parameters of water quality were within those recommended for tilapia cultivation. Feed consumption (p &lt; 0.05) and hepatosomatic index (p &lt; 0.05) were affected by the source used. Effects of supplemented selenium levels and sources were not observed for the other performance variables. Higher values for final height, final width, specific development rate and protein efficiency rate were found (p &lt; 0.05) when comparing the control diet with diets containing the sodium selenite source. No effects on muscle fiber morphometry were observed (p &gt; 0.05) in the studied variables. It is concluded that 0.6 mg of selenium in the diet, regardless of the source used, met the mineral requirement for post-larvae Nile tilapia.

Culturing live foods for fish larviculture using non‐microalgal diet: The role of waste‐generated bacteria and selected commercial probiotics—A review

AbstractCondensed suspension of live microalga cells, for example, Chlorella vulgaris, Nannochloropsis oculata and Tetraselmis tetrathele is often utilized as diets for mass production of live food resources, that is, rotifers, copepods, cladocerans and Artemia. These live food resources are essential for fish larviculture in hatcheries. However, the production of sufficient microalgae is costly, laborious and fragile, and thus require cost‐effective and stable production technologies, especially for the emerging countries. Studies have shown that locally available biowastes such as fish wastes and chicken manure provide substrates for generating billions of heterotrophic bacterial cells and microparticles as well as growth hormones, which can be used in propagating live food resources. The fish wastes contain essential nutrients that are important for the growth of both live foods and fish larvae. With single feeding of fish wastes, the culture condition of live foods may become unstable, and thus bacterial isolates and selected probiotics, for example, genus Pseudomonas, Moraxella and Micrococcus are needed to stabilize the culture conditions to increase reproduction capacity of the cultured live foods. This article consolidates the results and conclusions of our recent studies on the culture of live food resources, that is, Proales similis de Beauchamp, Brachionus rotundiformis Tschugunoff, Tigriopus japonicus Mori and Diaphanosoma celebensis Stingelin, using waste‐generated bacteria from fish waste diet (FWD) and selected probiotics. The non‐algal materials reviewed in this article are important to ensure constant supply of cheap live foods to improve aquaculture, especially in the developing countries, which lack sophisticated technology for production of high‐density microalgae.

Application of genetic disruption of a Nannochloropsis oceanica cell wall synthesizing gene to n-3 HUFA enrichment of Brachionus plicatilis

It is believed that microalgae of the genus Nannochloropsis can replace fish oil as an n-3 highly unsaturated fatty acid (n-3 HUFA) source in live feed for sustainable marine fish larviculture. This is due to the fact that these microalgae are rich in eicosapentaenoic acid (EPA). On the other hand, the cell wall of microalgae is an obstacle to enriching live feed with n-3 HUFA. Manipulation of the cellulose synthase gene has the potential to facilitate degradation of the cell wall structure, although little is known how effective the genetically modified microalga would be in n-3 HUFA enrichment of live feed. This study aimed to evaluate the significance of the cellulose synthase gene-knockout strain (ΔCESA) of N. oceanica as an EPA enrichment diet for Brachionus plicatilis. The transgenic microalga was established via homologous recombination, and cultured under the same conditions as the wild-type strain (WT). According to the cellular ultrastructure, ΔCESA had a thinner cell wall than WT and its outer layer was unnaturally peeled back. Biochemical analysis revealed that with the exception of carbohydrates, WT and ΔCESA had comparable levels of proteins, lipids, and EPA. Carbohydrates were lower in ΔCESA than WT, which can cause changes in the cell wall structure. Digestive enzymatic and mechanical treatments of microalga showed ΔCESA to have higher accessibility of intracellular fatty acids. When microalga was used as the diet in the long-term cultivation of rotifers (1 week), rotifers fed ΔCESA presented higher growth rates than those fed WT. In short-term cultivation for rotifer EPA enrichment (≤24 h), the percentage of EPA in neutral lipids and phospholipids increased more rapidly in rotifers fed ΔCESA than those fed WT. As a result, rotifers fed ΔCESA for only 12 h exhibited comparable EPA levels to those fed WT for 24 h. The results of this study suggest that the efficiency of n-3 HUFA enrichment of rotifers is enhanced by feeding cellulose synthase gene-disrupted N. oceanica, due to the high vulnerability of its cell wall and unchanged nutritional value. Our findings provide evidence that gene modification technology can be applied to improve the targeted biological characteristics of microalgae used as the source of n-3 HUFA in marine larviculture.

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

Simple SummaryThe success of marine fish farming is primarily determined by diet in early life. While both artemia and rotifers are commonly used as live feed in aquaculture laboratories in Peru, there has been little work studying the use of native food species. Here, we report our research on the use of a native copepod (Oithona nana) for its potential use in Peruvian marine aquaculture. We collected specimens of the native copepod O. nana and performed culturing experiments with two microalgae that have been widely used in aquaculture. Results show that this species adapted positively to our culture conditions, achieving high densities. We also report on the copepod’s reproduction and growth characteristics. Because of these promising results, we recommend that O. nana be studied further and propose it as a species with potential use as a live feed.Several species of the planktonic free-living genus Oithona have been successfully used in the larviculture of marine fish and shrimp. However, few studies have been published that allow us to estimate the potential of Oithona nana culture under controlled conditions. This work evaluated the effect of the microalgae Isochrysis galbana and Chaetoceros calcitrans as single (200,000 cells/mL) and mixed diets (100,000 + 100,000 cells/mL) on population and individual growth, ingestion rate, number of spawnings, fertility, development time by stage, and sex ratio of O. nana. We cultured this copepod at 28 ± 0.5 °C, 35 PSU salinity, 125 lux, and 12:12 photoperiod. Results showed that diet had no effect on the final population level (6273–7966 ind/L) or on individual growth, nor on sex ratio, with less males than females. With C. calcitrans, O. nana had a higher filtration rate (57 ng C/ind/day). On the other hand, a mixed diet induced a higher number of spawns (0.4 events/day) and nauplii per spawn (23 ind). Similarly, a single or mixed diet, containing I. galbana, accelerated the development rate by 6.33–7.00 days. We concluded that O. nana can be cultured with both microalgae, indicating its potential use in an intensive system for production. However, more research is required to improve the productivity of O. nana rearing.

Effects of live feed manipulation with algal‐derived antimicrobial metabolites on fish larvae microbiome assembly: A molecular‐based assessment

Opportunistic microorganisms acquired through rearing water or live feed ingestion are believed to underpin high mortality rates of fish larvae, constituting a production bottleneck for the aquaculture industry. We employed 16S rRNA gene sequencing to determine whether treatment of live feed (rotifers and Artemia) with algal-derived, antibacterial metabolites could alter bacterial community structure of gilthead seabream (Sparus aurata) larvae in a larviculture facility. Owing to a large degree of sample-to-sample variation, pronounced ‘legacy effects’ of live feed manipulation on the total fish larvae bacterial community could not be verified. Notwithstanding, the approach induced shifts in relative abundance of specific bacterial phylotypes in both the live feed and fish larvae. Some phylotypes representing opportunistic taxa such as Stenotrophomonas, Pseudomonas and Klebsiella displayed reduced abundances in the bacterial community of fish larvae fed metabolite-treated vs. control live feed. Conversely, potentially beneficial phylotypes in the Alphaproteobacteria clade were consistently—although not significantly—promoted in the treated larval samples. These outcomes encourage future microbiome manipulation attempts to improve fish larviculture. However, successful host colonization and competition with resident symbionts are primary barriers that need to be overcome if live feeds are to be used as effective delivery systems of beneficial bacteria to fish larvae.

Induced quiescence in eggs of the tropical calanoid copepod Acartia tropica : Effect of different storage conditions

Copepods of genus Acartia are considered as efficient live feeds for marine fish larviculture. A few reports are already there on production and storage for eggs of few temperate species of Acartia. Present study evaluated the storage potential of eggs of a tropical calanoid copepod, A. tropica. Different conditions examined were higher salinity storage (40–200 ppt) at room temperature, cold storage (4ºC) at different salinities (15–200 ppt), cryoprotectant solutions (methanol, glycerol) and antibiotic solutions (kanamycin, oxytetracycline). Results showed that higher salinity storage (50–200 ppt) could not retain egg viability under cold storage, as well as normal temperature conditions. The eggs exposed to cold storage and lower salinities (15–40 ppt) for 24 h survived with highest egg-hatching success (EHS, %) recorded at 15 ppt (69.44 ± 8.12). The condition was not efficient to retain egg viability beyond 24 h. The addition of certain cryoprotectants and antibiotics to the storage media significantly improved the survival of A. tropica eggs after 48 h storage. In the cryoprotectant treatments highest EHS after 48 h storage was recorded at 1M Glycerol (41.27 ± 6.34). Amongst the antibiotic treatments highest EHS after 48 and 72 h of storage were recorded at 100 ppm Kanamycin (46.79 ± 10.33, 2.67 ± 0.35) and 50ppm Kanamycin (43.86 ± 12.81, 1.73 ± 0.27), respectively. A drastic reduction in egg viability was recorded after 48 h and the antibiotics and cryoprotectants examined were not efficient to retain egg viability beyond 72 h. Hence the conditions examined in the present study could retain the viability of A. tropica eggs maximum up to 72 h and were not sufficient to induce long term quiescence in A. tropica eggs.

Transition to Artemia feeding phase for orchid dottyback Pseudochromis fridmani larvae: Establishing suitable prey shift time and strategy

Marine finfish hatcheries often replace small live prey with the larger traditional prey, brine shrimp Artemia, to feed the growing fish larvae. However, research on fish larviculture, including marine ornamental fish, often overlooks the importance of fine-tuning such prey transition. This study investigated the suitable time and approach for the larvae of an ornamental species, orchid dottyback Pseudochromis fridmani, to transit to the Artemia feeding phase. In experiment I, the suitable prey shift time window was estimated by abruptly feeding P. fridmani larvae with newly hatched Artemia nauplii (AN) from 5, 8, 11 or 14 days post-hatching (DPH) until 19 DPH. Although P. fridmani could ingest AN from 5 DPH, the final larval survival of 11-DPH and 14-DPH treatments were significantly higher, and it might relate to the enhanced digestive capability of older larvae. In experiment II, when prey shift began on 9, 11, or 13 DPH, the larvae were either abruptly shifted (AS) to AN feeding, or given a three-day gradual transition (GT) period of co-feeding original prey (rotifers and copepods) with AN before completing the prey switch. By 22 DPH, the prey shift strategy of GT significantly improved larval survival compared to the AS treatments; prey shift time treatments of 11-DPH and 13-DPH also reached significantly higher survival than 9-DPH treatments. However, survival of all individual treatments continued to decrease in the final stage of experiment. To further improve the prey transition success, experiment III investigated the effects of Artemia enrichment and prey shift time, by abruptly feeding larvae with either AN or enriched Artemia metanauplii (EA) from 9, 11, or 13 DPH onwards. Although the larvae fed AN were significantly larger than those fed EA, the absolute differences were small. There was a significant interaction between Artemia type and prey shift time on larval survival. The EA-11-DPH and EA-13-DPH treatments maintained steady survival post prey transition, and reached the highest mean survival of 58 ± 10%, and 55 ± 12% by 20 DPH, respectively. Moreover, while the larvae fed AN abnormally reduced prey intake over time, most larvae in EA-11-DPH and EA-13-DPH treatments still maintained high Artemia ingestion. These results suggest that dietary highly unsaturated fatty acids in enriched Artemia were crucial for larval survival of P. fridmani. Overall, this study shows that P. fridmani larvae could skip AN and directly feed on EA from 11 DPH without compromising survival or feeding performance.