Feed For Fish Larvae Research Articles

Transcriptome analysis reveals the importance of phototransduction during the first-feeding in mandarin fish (Siniperca chuatsi).

The mandarin fish (Siniperca chuatsi), as a typical freshwater carnivorous fish, has high economic value. Mandarin fish have a peculiar feeding habit of feeding on other live fry during the first-feeding period, while rejecting zooplankton or particulate feed, which may be attributed to the low expression of zooplankton-associated gene sws1 in mandarin fish. The domesticated strain of mandarin fish could feed on Artemia at 3 days post hatching (dph). However, the mechanism of mandarin fish larvae recognize and forage Artemia as food is still unclear. In this study, we employed transcriptional analysis to identify the representative differential pathways between mandarin fish larvae unfed and fed with Artemia at 3 dph. The comparative transcriptome analysis has unveiled a tapestry of genetic expression, highlighting 403 genes that have been up-regulated and 259 that have been down-regulated, all of which constitute the differentially expressed genes (DEGs). KEGG pathway analysis revealed that the number of differentially expressed genes in the photoconductive signaling pathway was the largest. Next, the Vorinostat (suberoylanilide hydroxamic acid, SAHA) was used to assess whether sws1 induced ingestion of Artemia in mandarin fish larvae. We discovered that SAHA-treated larvae had more food intake of Artemia and up-regulated the transcription level of npy, which might have been associated with the up-regulated of sws1 opsin. Additionally, exposure to 0.5 µM SAHA increased the expression of genes involved in phototransduction pathway. These findings would provide insights on the molecular processes involved in mandarin fish larvae feeding on Artemia at the first-feeding stage.

A probabilistic foundation for the study of larval fish feeding, growth, and mortality rates

Survival through the larval phase is predicated on the probabilities of successful feeding, which dictates growth rates, and the probabilities of encountering predators. Here I perform a synthesis of feeding, growth, and mortality rates estimated during several studies from coastal Newfoundland, Canada, to provide a description of the probability distribution that can serve as a foundation of the expected distribution of vital rates. The standardized observations clearly follow that of skewed distributions, appropriately fit to a probability gamma distribution, with feeding demonstrating a stronger degree of skewness than either mortality or growth, possibly because each vital rate integrates prey–predator interactions over different time scales. Commonality in the underlying form of the distribution of vital rates in larval fish, along with clear functional relationships between gamma parameters, represents a probabilistic basis of expectations against which observations from prior or new studies can be contrasted. An example of the use of such expectations demonstrates that they can provide useful contextual information about the contrast among observations and our ability to identify their relationship with environmental drivers.

VARIASI TANAMAN AIR SEBAGAI MEDIA UNTUK PERTUMBUHAN CACING SUTRA (Tubifex sp.) DENGAN SISTEM RESIRKULASI AIR

Silk worms is very popular and effective feed for fish larvae or fish seeds because of their high nutritional value such as protein, fat, minerals, vitamin B12, amino acids and unsaturated fats to fulfill the nutritional needs for the growth of fish seeds. This study aims to analyze the differences in water plants as a media cultivation silk worm to the growth of silk worms and to analyze water plants suitable as a media for silk worm that is able to provide high growth. This study used a completely randomized design (CRD) using 5 treatments and 3 repetitions, that is treatment A 100% mud, treatment B 50% mud + 50% apu wood, treatment C 50% mud + 50% kiambang, treatment D 50% mud + 50% water hyacinth and treatment E 50% mud + 50% genjer. The results of the study, treatment C 50% mud + 50% kiambang is the best for growth in long and weight of biomass. The results of the analysis of water quality are still in the optimal range for silk worm cultivation: 26,5oC-26,5oC, DO 2,50-4,32 mg/L, pH 6,19-6,11 dan ammonia 0,01mg/L.

Evaluation of the Viral Diversity of Artemia Cysts from Saline Lakes in Kazakhstan Using Viral Metagenomics Analysis

Artemia (brine shrimp) holds significant value as a live feed for larval fish and crustaceans, owing to their distinctive dietary requirements. However, it is vital to acknowledge that Artemia also carries potential risk as a vector of infection. We conducted a metagenomic analysis to explore the virome present in Artemia cysts collected from inland salt lakes across four distinct regions in Kazakhstan. This study identified the presence of dsDNA phages and RNA virus sequences, with a predominant representation from the Reoviridae, Nodaviridae, Dicistroviridae, Picornaviridae, Astroviridae, Tombusviridae, and Solemoviridae families. In general, this study has significantly enhanced our understanding of the virome of Artemia cysts in the saline lakes of Kazakhstan; however, the interactions between these putative viruses and brine shrimp and other aquatic animals need further research.

Importance of Infusoria as Live Feed for Fish Larvae and its Cultivation Techniques

Importance of Infusoria as Live Feed for Fish Larvae and its Cultivation Techniques

Assessing the determinants of larval fish strike rates using computer vision

Measuring behaviors that affect fitness is a critical task in the study of ecology and evolution. Behaviors such as feeding, fleeing predators, fighting conspecifics and mating are critical to an individuals’ fitness but are often unpredictable in space and time and can be rare in natural and experimental systems. Sparsely occuring behaviors are therefore difficult to quantify, and extracting them from video streams is extremely time consuming. In this study, we use a case study of larval fish feeding, a sparse behavior that is critical to larval survival, to demonstrate how an AI-assisted system can be applied to overcome the problem of quantifying sparsely occuring events. We deployed our system in aquaculture rearing ponds to directly estimate the strike rate of larval fish outside the laboratory for the first time, and assess the effects of environmental factors on these rates. Our analysis pipeline far surpassed the performance of manual annotation, both in terms of time efficiency and its ability to retrieve feeding strikes. We found that strike rates were similar and low across age groups, irrespective of pH and oxygen levels. However, strike rates increased significantly with increasing temperature. Our system allowed probing into the biology of a sparsely occuring behavior with unprecedented efficiency. However, it revealed that analyzing rare behaviors requires further development of research methodologies suited for low sample sizes and highly imbalanced data.

Effects of mono and mix diets on growth of Artemia and its application as dietary sources of Pterophyllum scalare (Angelfish)

Artemia is a type of brine shrimp that can provide good nutrients and a well digested fish larva with high potential live feed. Therefore, Artemia is readily contained in capsulated cysts that have been preserved for a long period of time. In the industrial, however, there is a lack of knowledge and technique regarding the handling of suitable life feed as first feed for fish larvae. The study is to observe the growth and survival rate of Angelfish larvae (Pterophyllum scalare) with various types of enriched Artemia. Three types enrichment are used (Tetraselmis sp., Chlorella sp., and mixed diet; Tetraselmis sp. + Chlorella sp.). This experiment was performed for 35 days, and the growth (SGR), survival and nutritional analysis were reported to assess the effect of the larvae of Angelfish. Specific growth rate (SGR) of Angelfish larvae (11.49 ± 0.63%), and survival rate (81.0 ± 1.92%). Angelfish larvae had the highest growth and survival rate on mixed diet fed (Tetraselmis sp. + Chlorella sp.) compared to other enrichments, Tetraselmis sp. (9.56 ± 0.08%, 70.00 ± 0.00%) and sp. (10.03 ± 0.13%, 74.0 ± 2.03%), this was related while examining the protein and lipids. The mean value of the mixed diet protein and lipid analysis (57.91 ± 0.27%, 7.31 ± 1.35%) is the highest as compared to other enrichments, Tetraselmis sp. (44.73 ± 0.73%, 4.85 ± 0.60%), and Chlorella sp. (49.76 ± 1.19%, 7.31± 5.05%). As the conclusion, mixed diet is more successful diet for growth performances and survival rate to fish larvae. This study applies if the Artemia can be culture in the future without the technique of decapsulation cysts to reduce cost in using Artemia.

The composition of monounsaturated fatty acids of artemia enriched with biologically active substances

The work is devoted to the study of monounsaturated fatty acids (MUFA) content in artemia enriched with biologically active substances at different stages of ontogenesis. Artemia cysts are used in the preparation of dietary supplements, highly effective feed additives for farm animals, fertilizers for crop production, chitosan for pharmaceutical industry and cosmetology, as raw materials in many other fields. When growing fish, crustaceans, shellfish in aquaculture, artemia nauplii are used as live starter feeds, which are obtained in situ when cultivating artemia cysts. Recently, the direction of enrichment of artemia nauplia used for feeding fish larvae and fry with biologically active substances has begun to develop: vitamins, essential amino acids, essential fatty acids, probiotics. In our work, we used a feed additive for the enrichment of artemia nauplia, including: vitamin-amino acid complex – «Chiktonic», probiotic – «Vetom-1», adaptogen – «Trekrezan», hemp oil. Enrichment was carried out through the skin at the stage of early nauplia. The aim of the work was to study the composition of MUFA at different stages of ontogenesis in intact artemia and artemia enriched with biologically active substances. The main function of MUFA is to activate metabolic processes and maintain homeostasis. When identifying monounsaturated fatty acids of artemia, the race we studied, the following were identified: oleic, palmitoleic, eicosenic, elaidic, erucic, nervonic, myristoleic acids. Oleic, palmitoleic and eicosenic fatty acids played a dominant role in the structure of MUFA. Two fatty acids, erucic and elaidic, can be distinguished in the composition of MUFA, the content of which was minimal.

Role of Rotifers in Betanodavirus Transmission to European Sea Bass Larvae.

Marine invertebrates such as rotifers or Artemia, frequently used for fish larvae feeding, can be a potential source of pathogens. It has been demonstrated that Artemia can act as a nervous necrosis virus (NNV)-vector to Senegalese sole larvae. Therefore, in this study, we aimed to clarify the role of rotifers in NNV transmission to sea bass larvae following an oral challenge. Our results showed that sea bass larvae fed on a single dose of rotifers retaining NNV displayed clinical signs, mortality, and viral replication similar to the immersion challenge, although the course of the infection was slightly different between the two infection routes. Furthermore, we also demonstrated that rotifers can internalize NNV particles due to their filtering nature and maintain virus viability since viral particles were detected by immunohistochemistry, immunofluorescence, and cell culture within the rotifer body. However, viral quantification data suggested that rotifers are not permissive to NNV replication. In conclusion, this research demonstrated NNV horizontal transmission through rotifers to sea bass larvae, highlighting the importance of establishing strict routine controls on live food to prevent the introduction of potential pathogens to hatcheries.

Optimal photoperiod for the reproduction of Eurytemora pacifica: potential live feed for fish larvae

Optimal photoperiod for the reproduction of Eurytemora pacifica: potential live feed for fish larvae

Declining Pre-bloom Calanus finmarchicus Egg Production Adjacent to Two Major Overwintering Regions in the Northeastern Atlantic

Calanus finmarchicus is a key secondary producer in the North Atlantic. Shortly prior to the spring bloom the animals ascend from diapause at depth to surface waters, where the females spawn partly, based on winter lipid reserves. C. finmarchicus eggs are an important prey of first feeding fish larvae inhabiting North Atlantic shelves during early spring and are thus essential for larval survival. Comprehensive late April surveys have been carried out on and around the Faroe shelf, which is located between the Northeast Atlantic and the Nordic Seas, for more than two decades. One aim is to investigate the critical match-mismatch between the spring bloom development, zooplankton reproduction and occurrence of first feeding fish larvae. In this study, we examine spatial and temporal changes in pre-bloom reproductive activity of C. finmarchicus on and around the shelf using a unique dataset of more than 8,000 examined females sampled during the period 1997–2020. Enhanced productivity was observed on the north-western side of the shelf, where the main flow of oceanic water to the inner permanently well mixed shelf takes place. We attribute this increased productivity to enhanced food (phytoplankton) availability in the seasonally stratified outer shelf, slightly upstream of the main egg production area. Both individual egg production rates and the fraction of spawning females declined throughout the Faroe shelf during the examined period. This decline could not be explained by the employed environmental parameters. The declining pre-bloom egg production may have consequences for first feeding fish larvae.

Does structural change in the zooplankton community affect larval fish feeding in anthropogenically disturbed tropical waters?

Does structural change in the zooplankton community affect larval fish feeding in anthropogenically disturbed tropical waters?

First feeding of grass carp (Ctenopharyngodon idellus) with a high-carbohydrate diet:the effect on glucose metabolism in juveniles

The effective utilization of carbohydrate feed sources is important to save protein feed resources and reduce formula feed costs in fish aquaculture. The present study investigated whether high-carbohydrate diet stimulus in the early larval stage of the grass carp (Ctenopharyngodon idellus) could affect glucose metabolism in subsequent life stages (i.e., the juvenile). A 73-day feeding trial was divided to five groups (four treatments and a control). The trial was conducted from the first feeding of larval fish. During the first 66 days, the control was continuously fed a commercial grass carp diet (CD), the FF-3 group was initially fed with 60% malty dextrin diet (MD) for 3 days and then with the CD for 63 days, the YE-7 group was initially fed with 60% MD after yolk-sac exhaustion for 7 days and with the CD for 56 days, the FF-10 group was initially fed with 60% MD for 10 days and then with CD for 56 days, and the FF-66 group was continuously fed to 60% MD. During the next 7 days, all the treatment groups and the control were fed with 35% MD as challenge test. The results showed that short-term stimulation with high-carbohydrate resulted in significantly increased body weights. After 73 days of feeding, the final body weights of the FF-3 and YE-7 groups were significantly higher than that of the control. Early high-carbohydrate manipulation changed the normal structure of the gut tissues of juvenile fish. After a short challenge test (7 days) performed with a 35% carbohydrate diet in juvenile grass carp, the results showed that high-carbohydrate dietary histories affected plasma metabolites and liver (muscle) glycogen storage in the juvenile fish. The mRNA levels of glucokinase and fatty acid synthetase genes increased significantly at the juvenile stage in the first-feeding groups. The phosphoenolpyruvate carboxykinase gene expression in the FF-3 and FF-10 groups decreased by varying degrees. The glycogen synthase gene expression levels in all groups were not affected. Long-term intake of high-carbohydrate feed (FF-66 group) led to the nutritional deficiency and disorder of the glucose metabolism system. In conclusion, our results demonstrated that a high-carbohydrate diet stimulus at first-feeding stage can affect the growth performance, gut morphology, and the homeostasis of glucose metabolism in juvenile of grass carp.

Enrichment of Larval Fish Feed with Free Amino Acids and Proteins by Coating with Lactobacillus paracasei subsp. paracasei BGHN14 Homogenate

This research aimed to test whether coating with Lactobacillus paracasei subsp. paracasei BGHN14 homogenate may increase soluble protein and amino acid amount on larval fish feed surface. Total amino acid and protein, as well as taste stimulating and growth promoting amino acid amounts were analyzed in coated feed samples. Results indicated that coating with BGHN14 homogenate increased the amount of soluble proteins and free Glycine on feed surface, as well as the availability of protein-bound (hydroxy-)Proline. This lab-scale research provides the basis for use of lactobacilli as resource efficient source of soluble nutrients for animal feedstuffs.

Cultivation success and fatty acid composition of the tropical copepods Apocyclops royi and Pseudodiaptomus annandalei fed on monospecific diets with varying PUFA profiles

Large-scale copepod production is limited by high-complexity production of microalgae with high contents of polyunsaturated fatty acids (PUFA). However, the tropical A. royi and P. annandalei show great promise of being cultivable on diets with less PUFA content while maintaining both population density and adequate fatty acid (FA) profiles. This ability was investigated through analysis of population density, development stage composition and FA compositions when fed diets of varying FA profiles: the microalgae Dunaliella tertiolecta and Rhodomonas salina, and baker's yeast, Saccharomyces cerevisiae. For A. royi, the population density (>1,600 L−1) did not differ significantly when fed these food items, nor did the relative content of the essential FA, docosahexaenoic acid (C22:6n-3, DHA), >28% of total FA (p < .05). P. annandalei did not reproduce when fed S. cerevisiae, but population density (>300 L−1) and DHA content (30%–60% DHA of total FA) did not differ significantly when fed D. tertiolecta and R. salina (p < .05). Eicosapentaenoic acid (C20:5n-3, EPA) content of both copepods differed dependent on the diet, but the resulting DHA:EPA ratio were >2, the optimal for live feed for fish larvae. These findings demonstrate possibilities of utilizing A. royi and P. annandalei in intensive aquaculture, exploiting cheaper diet alternatives, and possibly reducing total production cost and complexity.

Oyster larvae as a potential first feed for small-mouthed ornamental larval fish

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 11:657-669 (2019) - DOI: https://doi.org/10.3354/aei00338 Oyster larvae as a potential first feed for small-mouthed ornamental larval fish Alexander J. Basford*, Benjamin Mos, Tomoki Mishina, Symon A. Dworjanyn National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW 2450, Australia *Corresponding author: alex.basford@scu.edu.au ABSTRACT: Aquaculture of ornamental marine fish for the aquarium trade is a possible solution to the negative environmental impacts of wild collection. An impasse to the culture of many marine fish species is high larval mortality due to unsuitable live feeds. Common live feeds can be too large for ornamental species, which often have larvae with small mouths. We tested wild oyster larvae as an alternative live feed for first-feeding blue tang Paracanthurus hepatus. P. hepatus readily consumed oyster larvae but did not consume rotifers. Survival and growth of P. hepatus fed oyster larvae was similar to unfed controls, likely due to the oyster trochophores developing into indigestible veligers. Restricting the diet of P. hepatus to only oyster trochophores improved survival and eye development, but survival rates remained low. Oyster trochophores were conditioned in pH 4.8 seawater to compromise their aragonite shells, and P. hepatus fed these had higher survival at 5 d post-hatch (dph) compared to those fed untreated trochophores and were the only fish surviving to 10 dph. The high consumption rates of oyster larvae by P. hepatus highlight the potential for bivalve larvae to be used as live feeds for first-feeding larval fish. Further research into improving the nutritional value of oyster larvae for larval fish may improve their viability as first feeds. KEY WORDS: Acidification · Blue tang · Paracanthurus hepatus · Fatty acids · Live feeds · Larval rearing Full text in pdf format Supplementary material Corrections to supplement PreviousNextCite this article as: Basford AJ, Mos B, Mishina T, Dworjanyn SA (2019) Oyster larvae as a potential first feed for small-mouthed ornamental larval fish. Aquacult Environ Interact 11:657-669. https://doi.org/10.3354/aei00338 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 11. Online publication date: December 05, 2019 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2019 Inter-Research.

Improvement of nutritional quality of live feed for aquaculture: An overview

In hatcheries, the adequate supply of live feed has a vital role in feeding fish larvae, fry and fingerlings. Furthermore, the enhancement of the nutritional quality of live feeds is well-developed techniques in aquaculture. Essential fatty acids (EFA) such as docosahexaenoic acid (DHA; C22:6 n−3), eicosapentaenoic acid (EPA; 20:5(n−3) and arachidonic acid (ARA; 20:4(n−6) and amino acids are an essential source of proteins for larval rearing of fish. However, the common practised live feeds used for the primary feeding such as rotifers and Artemia are naturally deficient in essential nutrient components. Hence, the improvement of the nutritional quality of live feeds with different oil emulsions and commercial diets, and manipulation of the feed are necessary for fish production. The production protocols of copepods, Moina and fairy shrimps as live feed are still underdeveloped in hatcheries. The different lipid sources using for the enrichment of Artemia and rotifers are not effective on other live feeds, especially copepods and cladocerans (Moina, Daphnia) and fairy shrimps. This review focuses on the importance of live feeds by the techniques of feed enhancement or enrichment of zooplankton by direct incorporation of nutrients for feeding of early stages of fish.

ЭКОЛОГИЧЕСКИЕ АСПЕКТЫ ОРГАНИЗАЦИИ МНОГОВИДОВЫХ ГРУППИРОВОК ЛИЧИНОК РЫБ В ЛИТОРАЛИ РЫБИНСКОГО ВОДОХРАНИЛИЩА

The paper presents the results on the study of specific, spatial-temporal, age and trophic structures of groups of fish larvae feeding in the littoral zone of the Rybinsk Reservoir. The species composition and distribution of fish larvae were determined in biotopes of the protected vegetated coastal area in years of different water content. It has been pointed out that the dynamics of zooplankton in the spring period corresponds to the age-related changes in consumption of different groups of hydrobionts by fish larvae. There have been investigated the environmental factors ensuring the dissociation in time and space of potential competitors of the same trophic level accompanied by the divergence of food spectra and the division of food resources. Using as the example one of the structural and functional elements of the littoral biocenosis (multi-species groups of fish larvae), the role of the trophic factor which provides the organization and functioning of this biological system and gives it a balanced and integral character has been demonstrated. At the same time, the balance of food relationships was provided by such mechanisms as differentiation of individuals of different species of fish larvae according to the age principle, change of food objects during ontogenesis, and spatial separation.

Ихтиопланктон и трофические взаимоотношения в планктонных сообществах прибрежной акватории Юго-Западного Крыма (Чёрное море) в летний сезон 2013 г.

В прибрежной акватории Юго-Западного Крыма летом 2013 г. изучены видовой состав и количественные показатели мезо-, макро- и ихтиопланктона, а также питание личинок рыб. В ихтиопланктоне обнаружены икра и личинки 33 видов рыб из 24 семейств, что вдвое превысило показатели 1990-х гг. В мае 2013 г. в прибрежной акватории Севастополя наблюдался результативный нерест хамсы, которому способствовали благоприятная температура воды в море (+21 °C) и хорошие кормовые условия. Наибольшее количество летненерестующих видов зарегистрировано в июне при температуре поверхностной воды +22,7 °C. Численность икры рыб в 2013 г. увеличилась по сравнению с таковой в 2000 г. в 3,4 раза, личинок ― в 2,3 раза, что связано с их большей выживаемостью при улучшившихся условиях питания в результате относительно высокой численности зоопланктона с преобладанием мелкоразмерной фракции и доминированием в ней ювенильных стадий копепод. Другими факторами, улучшившими состояние кормовой базы личинок, были низкая численность гребневика Mnemiopsis leidyi A. Agassiz, 1865 и его слабое воздействие

The influence of macrophytes on the feeding of fish larvae in a shallow brackish sea

Abstract We studied the impact of the macrophyte stands on the feeding of fish larvae, paying special attention to feeding on ciliates. Generally, the importance of ciliates as larval food has been overlooked or underestimated. Based on our earlier observations we hypothesized that the consumption of ciliates by fish larvae is higher in vegetated areas. Studies were carried out in a shallow Vainameri Sea (semi-enclosed Baltic Sea basin). Fish were sampled over 3 years (2011−2013). We examined larval diet by gut segmentation and epifluorescence microscopy. The study revealed that: (1) larval food intake and condition factors were generally higher in vegetated areas; (2) ciliates represented a very important food source for larval fish; (3) in vegetated areas larval fish consumed more ciliates than in open water areas; (4) larvae of piscivorous fish species tended to catch larger prey items. In general our study suggests that larval growth may be better secured in vegetated areas.