“Whoa! It’s like Spotify but for academic articles.”

Instant Access to Thousands of Journals for just $40/month

Try 2 weeks free now

Amino acid requirements of fish larvae and post-larvae: new tools and recent findings

This paper reviews methodologies and recent findings in the study of the amino acid (AA) metabolism of fish larvae and post-larvae, in order to better understand the AA requirements. The larval indispensable AA (IAA) profile can be used as index of the IAA requirements. When turbot larvae and live food IAA profiles are compared, the profile of the latter seems to be deficient in some IAA. However, the larval IAA profile is only a rough indicator of AA requirements. A more precise estimate of the ideal dietary IAA profile implies the knowledge of the relative bioavailabilities of the individual AA, in particular, eventual differential rates of absorption and catabolism. Metabolic budgets (including unabsorbed AA, AA oxidation and AA retention) can be estimated using an in vivo method based on controlled tube-feeding of AA mixes containing a 14 C-labelled AA. Results with fasted post-larval Senegal sole ( Solea senegalensis ) and fasted herring ( Clupea harengus ) larvae show a high retention of labelled doses of IAA (>60%) in the body, compared to catabolism as measured by liberated 14 CO 2 (<25%). In contrast, dispensable AA (DAA) show a higher catabolism (>40%) and a lower retention (<57%). So, from the onset of exogenous feeding, fish larvae have high catabolic losses of AA, but use DAA preferentially to IAA as energy substrates. A new method combining the use of 13 C-labelled live food and 13 C-NMR spectroscopy can be used to study simultaneously the relative bioavailability of several individual AA in fish larvae. In larval gilthead seabream ( Sparus aurata ) fed on rotifers, relative bioavailabilities (a combined measure of absorption efficiency and rate of catabolism) vary between AA being high for aspartate, glutamate and lysine and low for threonine. These estimates of relative biovailability of individual AA together with the IAA profiles of the larval seabream indicate that rotifers are deficient in threonine and leucine for larval seabream, threonine being the first limiting AA for protein synthesis. In order to define ideal IAA profiles for larval fish, further studies are needed on the factors affecting the relative bioavailability of IAA, such as species, age, developmental stage, temperature and the dietary nitrogen molecular form(s). Estimates of relative bioavailability of individual AA together with the IAA profile of the larval protein allow to determine the ideal dietary IAA profile for a given species. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Aquaculture Elsevier
Loading next page...

You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy unlimited access and
personalized recommendations from
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $40/month

Try 2 weeks free now

Explore the DeepDyve Library

How DeepDyve Works

Spend time researching, not time worrying you’re buying articles that might not be useful.

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from Springer, Elsevier, Nature, IEEE, Wiley-Blackwell and more.

All the latest content is available, no embargo periods.

See the journals in your area

Simple and Affordable Pricing

14-day free trial. Cancel anytime, with a 30-day money-back guarantee.

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Best Deal — 25% off

Annual Plan

  • All the features of the Professional Plan, but for 25% off!
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

billed annually