Dietary Euterpe oleracea Essential Oil, the Amazon Açaí, as Feed Additive to Amazonian Ornamental Fish, during Post-Larvae Growing Stage: A Preliminary Study
, Jaqueline Gomes Cavalcante 2, Edileno Tiago de Sousa Nascimento 1, Isamaira Costa e Silva 1, Ana Lúcia Salaro 3, LuÃs André Luz Barbas 4, Galileu Crovatto Veras 5 and Daniel Abreu Vasconcelos Campelo 1,*Round 1
Reviewer 1 Report
This manuscript investigated the impact of dietary Euterpe oleracea EO as a feed additive on the post-larvae growth, survival rate, and batch uniformity of the Amazonian ornamental fish. The manuscript deals with an important topic in livestock production. However, the manuscript needs extensive revisions, and several concerns need to be addressed as follows:
Major concerns:
1) The plant collections, identification, and extraction method used for AEO production have not been given.
2) Which part of the plant was used (leaves, seeds, … etc) for AEO production?
3) The authors had to justify on what basis they selected the level of the tested AEO. The concentrations used (up to 2%) of tested essential oil are extremely high and uncommon in fish diets, especially for practical and economic applications. Most recent studies indicated that essential oil and plant extracts are usually added to fish diets as a feed additive was added within the range of 100 to 1000 mg/kg feed. This represents one of the major weaknesses.
4) The chemical composition and main active continents of plant essential oils vary according to several factors such as soil, climate, agricultural treatments ... etc. Also, the potential effect of essential oils is affected by their bioactive chemical composition, so I strongly suggest that the authors present the chromatographic profile (active components) in the AEO to support the obtained results.
Additional comments:
1) "açai" is a Portuguese term. It is highly recommended to be replaced with an English term throughout the manuscript.
2) The hypothesis of the study should be clarified before the aim at the end of the Introduction section.
3) The duration of the experimental period should be clearly mentioned.
4) Add more descriptions about experimental aquariums.
5) Table 1, it is impossible to get the same values of chemical composition for all the experimental diets. This is not true, and authors should be clearer when they mention any information in the manuscript because all the stated values of the composition of table 1, are IMPOSSIBLE to get them due to a difference in the formulations of the experimental diets.
6) In the statistical analysis section, what is the post hoc test you used?
7) Tables 2-3.: The letters of significance (a, b, c) should be added in case significant effects exist. Also, replace “P-valor” with “P-value”.
8) The introduction and discussion sections need to be updated with recent references.
9) The conclusion section is missing.
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The work of optimizing lipids in two may be of particular interest for ornamental fish production. However, substituting soybean oil with Acai oil seems not only to alter the fatty acid composition, but also the content of total antioxidants in the feed. An actual analysis of feed composition with regards to antioxidants and fatty acids are therefore missing, since only Total lipids and Crude Proteins, Fiber, and Energy were analyzed. Possible effects of antioxidants on the fish performance are discussed, but levels of antioxidants in the different feed treatments was not documented, making this part of the discussion a bit speculative.
Another important issue is that the formula used for specific growth rates (SGR) is erroneous, and unfortunately widely used in the scientific community. The correct formula for SGR is given by Ricker (1958), which I have included in my comments directly in the manuscript. This must be corrected in both the presentation of the results and statistical analyses.
Besides these issues, I have some minor linguistic and structural comments which is given directly in the manuscript.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
No further comments are to be addressed.
