An Endeavor to Find Starter Feed Alternatives and Techniques for Zebrafish First-Feeding Larvae: The Effects on Viability, Morphometric Traits, Digestive Enzymes, and Expression of Growth-Related Genes.
{"title":"An Endeavor to Find Starter Feed Alternatives and Techniques for Zebrafish First-Feeding Larvae: The Effects on Viability, Morphometric Traits, Digestive Enzymes, and Expression of Growth-Related Genes.","authors":"Seyed-Mohammadreza Samaee, Behrooz Atashbar Kangarloei, Farzaneh Noori, Alicia Estévez","doi":"10.1089/zeb.2020.1928","DOIUrl":null,"url":null,"abstract":"<p><p>Low and variable growth and survival rates (SR) of 6-10 days postfertilization zebrafish larvae are a problem. This problem seems to be linked to starter feed characteristics. This study is an attempt to find alternatives to address these requests. For this, larvae were fed fresh and lyophilized microalgae (<i>Chlorella</i>, <i>Scenedesmus</i>, and <i>Haematococcus</i>), egg yolk (YOLK), lyophilized <i>Artemia</i> nauplii (LAN), and a combination of them. The lowest SR was observed in algae-fed larvae. All died on day 11 showing an emaciated appearance, similar to starved larvae. The highest SR was observed in YOLK- and LAN-fed larvae, which also showed an elongated anterior part of the body. Negative correlations of SR with <i>vegfaa</i> (vascular endothelial growth factor) and morphometric traits with <i>igf2a</i> (insulin-like growth factor) were also found and supported by changes at the molecular level. The presence of algae in the digestive tract of the larvae and the observation of fecal droppings indicate that the algae have an appropriate size and are palatable. The increase in the digestive enzyme activity shows the larval effort to digest the algae. The fact that the algae-fed larvae died even before the larvae were kept in starvation indicates the dramatic amount of energy that the larvae spent in microalgae digestion. Although both YOLK- and LAN-fed larvae had the highest SR, LAN group started to feed on <i>Artemia</i> nauplii sooner. This can be linked to the delayed growth in YOLK-fed larvae and an accelerated growth in the case of LAN-fed group. LAN is an expensive feed with negative effects on water quality, whereas YOLK is a cheap and nutritionally balanced feed with fine granular texture that contributes to a larval SR similar to LAN without affecting water quality. In conclusion, microalgae cannot be considered a suitable starter food for zebrafish, whereas LAN and YOLK can be considered good starter feeds.</p>","PeriodicalId":23872,"journal":{"name":"Zebrafish","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Zebrafish","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1089/zeb.2020.1928","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/2/4 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"DEVELOPMENTAL BIOLOGY","Score":null,"Total":0}
引用次数: 5
Abstract
Low and variable growth and survival rates (SR) of 6-10 days postfertilization zebrafish larvae are a problem. This problem seems to be linked to starter feed characteristics. This study is an attempt to find alternatives to address these requests. For this, larvae were fed fresh and lyophilized microalgae (Chlorella, Scenedesmus, and Haematococcus), egg yolk (YOLK), lyophilized Artemia nauplii (LAN), and a combination of them. The lowest SR was observed in algae-fed larvae. All died on day 11 showing an emaciated appearance, similar to starved larvae. The highest SR was observed in YOLK- and LAN-fed larvae, which also showed an elongated anterior part of the body. Negative correlations of SR with vegfaa (vascular endothelial growth factor) and morphometric traits with igf2a (insulin-like growth factor) were also found and supported by changes at the molecular level. The presence of algae in the digestive tract of the larvae and the observation of fecal droppings indicate that the algae have an appropriate size and are palatable. The increase in the digestive enzyme activity shows the larval effort to digest the algae. The fact that the algae-fed larvae died even before the larvae were kept in starvation indicates the dramatic amount of energy that the larvae spent in microalgae digestion. Although both YOLK- and LAN-fed larvae had the highest SR, LAN group started to feed on Artemia nauplii sooner. This can be linked to the delayed growth in YOLK-fed larvae and an accelerated growth in the case of LAN-fed group. LAN is an expensive feed with negative effects on water quality, whereas YOLK is a cheap and nutritionally balanced feed with fine granular texture that contributes to a larval SR similar to LAN without affecting water quality. In conclusion, microalgae cannot be considered a suitable starter food for zebrafish, whereas LAN and YOLK can be considered good starter feeds.
期刊介绍：
Zebrafish is the only peer-reviewed journal dedicated to the central role of zebrafish and other aquarium species as models for the study of vertebrate development, evolution, toxicology, and human disease.
Due to its prolific reproduction and the external development of the transparent embryo, the zebrafish is a prime model for genetic and developmental studies. While genetically more distant from humans, the vertebrate zebrafish nevertheless has comparable organs and tissues, such as heart, kidney, pancreas, bones, and cartilage.
Zebrafish introduced the new section TechnoFish, which highlights these innovations for the general zebrafish community.
TechnoFish features two types of articles:
TechnoFish Previews: Important, generally useful technical advances or valuable transgenic lines
TechnoFish Methods: Brief descriptions of new methods, reagents, or transgenic lines that will be of widespread use in the zebrafish community
Zebrafish coverage includes:
Comparative genomics and evolution
Molecular/cellular mechanisms of cell growth
Genetic analysis of embryogenesis and disease
Toxicological and infectious disease models
Models for neurological disorders and aging
New methods, tools, and experimental approaches
Zebrafish also includes research with other aquarium species such as medaka, Fugu, and Xiphophorus.
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