Sagiv Kolkovski

• PhD
• Managing Director at Nutrakol Pty Ltd Australia

on the point-of-no-return (PNR), survival, and growth of yellowfin seabream Acanthopagrus arabicus larvae were studied under controlled condition. Growth parameters were investigated by evaluating morphometric (head depth, body depth, gut height, musculature height, eye diameter, total length, yolk, and oil globule volume) and gravimetric (dry weig...

This datasheet on Integration of agri-aqua systems - the Israeli experience covers Identity, Overview, Environmental Requirements, Growout Systems, Related Content, Further Information.

Israel is located in the Middle East between Africa, Asia and Europe. Like many semi-arid countries, it faces a water shortage due to limited rainfall and freshwater sources. However, in spite of climatic constraints and overall shortage of water, both agriculture and aquaculture are highly developed. Different methods and solutions to maximize wat...

Marine fish larvae fed microdiets have not, at this stage, matched the growth and survival performances demonstrated by larvae fed live feeds such as rotifers and Artemia. This chapter discusses the issues related to the use of microdiets as a sole or partial feed for marine fish larvae. The techniques and methods of manufacturing microdiet particl...

Aquaculture in desert and arid lands has been growing steadily over the last decade thanks to the modern technologies and alternative energy sources that have allowed water in these places of extremes to be exploited more effectively and more efficiently, using it for both crop irrigation and production of fish.This publication presents the evoluti...

Marine fish larvae fed microdiets have not, at this stage, matched the growth and survival performances demonstrated by larvae fed live feeds such as rotifers and Artemia. This chapter discusses the issues related to the use of microdiets as a sole or partial feed for marine fish larvae. The techniques and methods of manufacturing microdiet particl...

We conducted a study to investigate the effect of different levels of dietary highly unsaturated fatty acids (HUFAs) on tissue fatty acid profiles and reproductive performance in female zebrafish. In addition, the mRNA expression of desaturase and elongase genes in liver, muscle and ovarian tissues were also analysed. Three iso-nitrogenous experime...

During the past three decades, enormous efforts have been made to develop microdiets (MD) to replace live feed, both rotifers and Artemia, as complete or partial replacements for marine fish larvae. However, although, there were substantial achievements in reducing the reliance on live feeds and weaning the larvae earlier onto MD, still, in most sp...

Freshwater fish species possess higher capability to utilize plant based oils as dietary lipid source due to their ability to biosynthesize highly unsaturated fatty acids (HUFA) to meet requirements needed for growth and development. However, there is paucity in knowledge on the requirement for dietary HUFA in freshwater broodstock during active sp...

We conducted a study to determine the effect of dietary protein and lipid levels on the growth and reproductive performance of a freshwater ornamental species, the swordtail (Xiphophorus helleri). Two protein levels (20% and 30%) with four lipid levels (8%, 12%, 16%, 20%) within each protein levels were tested through formulation of practical diets...

Because of high costs and labour requirements along with the highly variable nutritional value of live feeds, we investigated the possibility of early weaning for barramundi (Lates calcarifer Bloch) larvae aimed at reducing the use of Artemia. Two commercial microdiets, Gemma Micro (Skretting, Australia) and Proton (INVE, Belgium) were compared for...

Since live feeds are costly and variable in nutrition, early weaning onto artificial microdiet is advantageous. Thus, we tested a new commercial microdiet using several rearing protocols aimed at reducing live feed inputs. Barramundi Lates calcarifer (BLOCH) larvae were reared from 2 days post hatch (dph) to 28 dph and their survival, growth and st...

Western rock lobster, Panulirus cygnus, phyllosoma were grown from hatching to stage IV. Larvae were fed with Artemia enriched with a (i) base enrichment (Base) containing 520 g kg−1 squid oil or tailor made enrichments in which oils high in polyunsaturated fatty acid (PUFA) have been added at the expense of squid oil. These treatments were (ii) ba...

The effect of dietary 22:6n-3 on larval striped trumpeter growth, morphology, feed intake and behaviour was investigated. A dose–response technique was used. Seven experimental emulsions were formulated with increasing concentrations of 20:5n-3 and 22:6n-3 and used to enrich rotifers (Brachionus plicatilis). Enriched rotifer 22:6n-3 concentrations...

Symphysodon aequifasciata liver polyunsaturated fatty acid elongase mRNA, partial cds

Live food such as Artemia is considered to be an essential part of any marine finfish hatchery. Standard methods were developed for hatching and enhancing the nutritional value of the Artemia nauplii by using different enrichment products. Although there is a variety of commercially available products in the market, further research on more specifi...

Live food such as Artemia is considered to be an essential part of any marine finfish hatchery. Standard methods were developed for hatching and enhancing the nutritional value of the Artemia nauplii by using different enrichment products. Although there is a variety of commercially available products in the market, further research on more specifi...

Biochemical and bacterial profiles of juvenile Artemia (1.5 mm, 5 days old) were examined in two experiments designed to manipulate their nutritional composition. In Experiment 1, Artemia were enriched for up to 36 h with the diatom Chaetoceros muelleri, the chromist Schizochytrium (Algamac 3050®) or a squid oil emulsion. In Experiment 2, Artemia w...

We determined the effect of dietary long-chain (≥C20) PUFA (LC-PUFA), 20∶5n−3 and 22∶6n−3, on larval striped trumpeter (Latris lineata) biochemistry through early development and during live feeding with rotifers (Brachionus plicatilis). Rotifers were enriched using seven experimental emulsions formulated with increasing concentrations of n−3 LC-PU...

The efficient delivery of nutrients and hormones has special relevance to the development of rearing technologies for fish larvae and juveniles. The main aim is to find an effective and measurable way to administer them into the body of small aquatic animals. In this study, three different compounds (hormones, amino acids, and vitamins) were incorp...

Background - Striped trumpeter (Latris lineata) is a marine finfish with aquaculture potential. Striped trumpeter has an extended larval phase and survival during this time is typically low. Similar constraints occur in larval marine finfish hatcheries worldwide that are often associated with inadequate fatty acid nutrition. Determining essential f...

The leaching loss of free amino acids (FAA) from an experimental protein-walled microencapsulated diet (MC) for larval fish after immersion in water was measured and compared with leaching loss from a gelatin microbound diet (MB) containing the same dietary ingredients. The loss of FAA (as a percentage of total dietary FAA) was significantly higher...

This study aimed to evaluate the effect of enriching Artemia nauplii with vitamin C (ascorbyl-6 palmitate) or vitamin E (α-tocopherol acetate), 20% w/w, together with a mixture of concentrated eicosapentaenoic acid (EPA, 20:5 n-3) and docosahexaenoic acid (DHA, 22:6 n-3) on the growth, survival, and stress resistance of fresh water walleye Stizoste...

In the present study, the use of predigested proteins as an ingredient of microdiets offered to gilthead seabream larvae was tested. The protein source (freeze-dried squid powder) was hydrolysed with protease (trypsin and pancreatin). Different levels of raw squid protein and hydrolysate (100% protein, 50% protein/50% hydrolysate, 100% hydrolysate)...

Dietary supplementation of phospholipids seems to be extremely important to promote growth and survival in fish larvae. Several studies also suggest the importance of n-3 highly unsaturated fatty acids (HUFA) rich phospholipids to further enhance larval performance. In the present study, four different diets were formulated in order to compare the...

Age-dependent changes in digestive tract anatomy/physiology during larval–juvenile ‘metamorphosis’ of fish have been examined with respect to diet, biochemical characteristics and nutrient utilization. In fish larvae, basal capacity and rates of the intestine to hydrolyze and transport specific nutrients is qualitatively and quantitatively set in g...

The performance of microdiets (MDs) for larvae of marine fish is frequently improved when they are co-fed with Artemia. This suggests that nutritional factors in the live food are positively influencing the ingestion, digestion and assimilation of the MD. This paper reviews recent advances in MD development on the gilthead seabream with special emp...

The performance of larval walleyes Stizostedion vitreum that were produced out of season was compared with larvae produced during a regular season, using intensive culture methods. Wild-captured walleye adults were held in an earthen pond beginning in late November and then gradually transferred to higher water temperatures before ovulation was hor...

Juvenile yellow perch Perca flavescens were evaluated to assess their needs for exogenous digestive enzyme and hormone supplementation in dry diets. Evidence exists to support the hypothesis that these supplements may assist young fish in digestion. Four diets were tested: a commercially available trout starter; an experimental diet based on high q...

— We determined the effect of krill hydrolysate as a feed attractant in three freshwater fish species: yellow perch Perca flavescens. walleye Stizostedion vitreium. and lake whitefish Coregonus clupeaformis. Growth trials were conducted using a commercial trout starter diet (control) and the diet that was coated with liquid krill hydrolysate. The k...

We quantified how addition of n−3 highly unsaturated fatty acids (HUFA) to brine shrimp (Artemia sp.) nauplii influenced growth, survival, osmotic challenge and fatty acid composition of juvenile walleye. Four groups of 6-day-old walleye were fed enriched Artemia. Lipids were altered to provide four treatments: (1) 100% cod liver oil (CLO), (2) 60%...

The effects of dry food type and live/dry food ratio on survival, growth rate and size distribution of juvenile gilthead sea bream were investigated. Dietary treatments consisted of a high (73.5%) and low (53.2%) protein diet based mainly on squid meal vs. soybean and fish meal, respectively, while live food consisted of Artemia nauplii. The effect...

This study tested the effect of the level of dietary phosphatidylcholine (PC) and its constituent medium-chain fatty acids on microdiet ingestion (μg diet larva−1 h−1) and the absorption rate of the free fatty acid [14C]16:0 (pmole larva−1 h−1) in 15, 20, 21, 25, 26, 30 and 31-day-old gilthead sea bream, Sparus auratus L., larvae. Fish were fed fou...

The thermal and light conditions for 2-year-old broodstock of yellow perch Perca flavescens were shifted by 6 months in an effort to change spawning from spring to autumn and fall. The natural photothermal conditions consisted of a chill period of 10°C and 10 h of light during January–March followed by increases in temperature to 20–22°C and photop...

The aim of the present study was to investigate the mechanisms by which the presence of Artemia nauplii in the rearing medium stimulates the feeding behaviour of gilthead sea bream, Sparus auratus. Sea bream larvae were given a microdiet ad libitum in the complete absence or the presence of chemical or visual stimuli of Artemia nauplii in the follo...

In recent years, a great deal of interest has been generated in the development of a microdiet (MD) as an economic live food alternative for the larvae of commercially important species of marine fish. Despite the poor performance of microdiets (MD) when used exclusively to rear marine fish larvae, results were markedly improved when inert MDs were...

The effects of live food (Artemia nauplii) and dietary supplementation of digestive enzymes (pancreatin) on ingestion and assimilation of dry microdiet (MD) and nutrient deposition and larval growth were studied in 20–39 day old seabass (Dicentrarchus labrax) larvae. Four treatments were tested at each age: (i) MD with Artemia nauplii; (ii) MD supp...

Protein digestibility by gastrointestinal homogenates of Dicentrarchus labrax, was investigated in 5 feeds in relation to their amino acids composition and their ability to sustain growth of D. labrax post larval juveniles. Gastric proteolysis was found to contribute <25% of the total proteolytic capacity. Correlation was found between intestinal p...

The success of microdiets commonly used in the cultivation of marine fish larvae is limited to serving as partial replacements for live food. This limited success is thought to be associated with a reduced digestive ability due to an incompletely developed digestive system. The enhanced growth obtained from live food has been partially attributed t...

The present study tested the effect of dietary lecithin and exogenous lipase on the incorporation of oleic acid in the tissue lipids of gilthead seabream larvae (Sparus aurata). Two of four microdiets were prepared by the addition of [14C]oleic acid as free fatty acid (FFA) to diets containing either 5% cuttlefish liver oil (CLO) or 5% soybean leci...