Sustainable Aquafeed with Marine Periphyton to Reduce Production Costs of Grey Mullet, Mugil cephalus
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsSome information about materials and methods should be added to the abstract.
Multiple references in the text should be arranged based on the journal's guidelines.
Some information about the experiment conditions should be added to the Materials and Methods section.
insufficient description of experimental design, materials, and methods generally.
Clearly state whether your objective is novel or not.
Comments on the Quality of English LanguageLanguage
Focus on writing more concisely, critically read the manuscript as there are many sentences that are repetitive
Minor editing of English language required
Author Response
Some information about materials and methods should be added to the abstract.
Revised. Following the reviewer's comment, information on M&M was added to the abstract.
Multiple references in the text should be arranged based on the journal's guidelines.
Revised. Following the reviewer's comment, the citations were double-checked and provided according to the following Journal's guidelines: [1] for a single reference; [1,2] for two references; or [1-3] for more than two references.
Some information about the experiment conditions should be added to the Materials and Methods section.
insufficient description of experimental design, materials, and methods generally.
Revised. Following the reviewer's comment, we added information on the experiment's conditions to the relevant sections (2.2.2 and 2.2.3) and improved the description of the experimental design and M&Ms.
Clearly state whether your objective is novel or not.
Revised. Information on the novelty of the research aim was added.
Focus on writing more concisely, critically read the manuscript as there are many sentences that are repetitive.
Revised. Following the reviewer's comment we revised the text to remove redundancy.
Minor editing of English language required
Revised. English editing was performed by a professional editor who is a native English speaker.
Reviewer 2 Report
Comments and Suggestions for AuthorsHigh cost and low efficiency are always the key limitation on the development of industries, so that lower cost and higher efficiency would be the permanent pursuit, particularly for mariculture. This manuscript attempt to substitute the ingredients of aquafeed with marine periphyton to reduce the production costs. Despite the experiment design is overall rational, some relevant contents were overlooked in this version, but very critical for this studies, which I think authors must added in disscussion. My concerns were listed as follows.
1. Despite lower the cost are very important for mariculture, the production rate should be also critical. As authors mentioned, reduce fishmeal in aquafeed would retard fish growth and decrease the survival rate of fish, so that more time feed and fingerlings input should be also produced more cost, which must be also considered into cost accounting, instead of only considering the aquafeed costing in a fixed period.
2. The final fish weight and length that after the entire experiment must list out, which helps to the understanding of the fish growth for readers.
3. The normal breeding period of Mugil Cephalus can not be found in the context. In the feeding trial, 104 days was performed, is this breeding period commonly for mariculture?
4. Line 336, the misspell of growth2 should be corrected.
Author Response
- Despite lower the cost are very important for mariculture, the production rate should be also critical. As authors mentioned, reduce fishmeal in aquafeed would retard fish growth and decrease the survival rate of fish, so that more time feed and fingerlings input should be also produced more cost, which must be also considered into cost accounting, instead of only considering the aquafeed costing in a fixed period. Response: Our economic analyses also provide the calculation of fish production cost in $ USD per 1kg of produced fish. While costs of feed is not enough (as also suggested by the reviewer), the calculation of fish production cost is derived from the following: a. fish growth rate; b. feed conversion ratio (the amount of feed that was required by fish to gain 1kg of body weight); and c. the cost of the feed. Therefore, such value provides a clear index for the farmer to understand whether the cost of production is still being reduced when growth is slower. We hope the reviewer can accept this analysis is valid and addresses the raised concerns.
2. The final fish weight and length that after the entire experiment must list out, which helps to the understanding of the fish growth for readers. Response: Revised. the ambient final weight under each diet was added to the text (in the relevant results section)
3. The normal breeding period of Mugil Cephalus can not be found in the context. In the feeding trial, 104 days was performed, is this breeding period commonly for mariculture?
Response: Breeding in mullets starts around the age of 24m. The current study was performed on fingerlings at the age of 2-3M.
4. Line 336, the misspell of growth2 should be corrected.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors address a current and quite interesting topic such as generating food alternatives for the livestock sector. It is considered that the information provided in the manuscript is of quality and that it provides valuable information of interest to the readers of the journal. The observation made in this manuscript is that the addition of nutritional and/or nutritional information by periphyton is considered necessary, in order to know in a more focused way the contribution of this additive to the diet and how it influences the macronutrient composition already in the fish. Such information would provide greater support for the conclusions expressed in the manuscript. Regarding the format, there are some formulas where it is necessary to use superscripts or subscripts depending on each one, as well as the unification of the use of italics in some scientific names.
The manuscript addresses a topic of current interest in addition to being innovative since it proposes the incorporation of non-conventional materials (Periphyton) in the generation of fish diets.2.-In this context, it is considered a relevant issue given the importance of the livestock sector and the growing need to generate more economical alternatives for the production of fish with optimal, viable and economical inputs.3.-Although in the study of viable alternatives to economize in the generation of diets for fish there are several related articles, to date I am unaware of any article where Periphyton is included as an additive to the diet and specifically that would be the relevant contribution in The manuscript.4.- The improvements that I consider should include is the characterization of Periphyton given that it can come from various sources and the nutritional and nutraceutical contribution of this additive in diets can be from greater to lesser relevance or impact in various ways.5.- As mentioned in the previous report, the conclusions indicated by the authors are good, however the addition of the information or characterization of Periphyton will provide additional information that can contribute to reinforce the conclusions already expressed in the manuscript.6.- In relation to the references, I consider them to be adequate, the vast majority of them are in accordance with the discussion of the results, they support the methodology part, in addition to being current and related to the topic developed in the manuscript.7.-In relation to the tables, I would like them to be within the manuscript to facilitate their understanding, however I understand that it is an editing issue specific to the journal. The information presented in the tables is adequate and provides a good understanding of them.
Author Response
Response: The current study aimed to evaluate: a. whether periphyton is feasible in replacing fishmeal in aquafeed for mullet fingerlings; and b. to what extent such substitute is efficient in the aquafeed. Fishmeal contains about 70% protein in the dry biomass and is used as the primary protein source in aquafeeds for mullets. It is also a source of lipids but such contribution is considered minor. That said, the current research focused on examining the potential of periphyton's protein (and perhaps also lipids) in substituting fishmeal's protein (and perhaps also lipids). Our results propose that periphyton with 32% of protein can be used to reduce fishmeal (with 70% protein) by 25-50%. We agree with the reviewer that, like other ingredients in aquafeeds (from plants and animals), Periphyton's content of protein (and other macro- and micro-nutrients) can vary due to many factors (seasonal changes, nutrient source, etc.). Therefore, when used as a substitute for fishmeal, analysis of the biochemical content of periphyton is needed to calculate its required portion in the aquafeeds. It should also be noted that there is not much information in the literature about the biochemical content of periphyton in general, nor on the content of nutritional ingredients in this biomass, and how changes are due to environmental factors. That said, we revised the text and added some recommendations, from our experience (from previous studies on periphyton as a biofilter) and from the literature, on how to improve the protein and lipids content in the biomass (e.g., using silicate to induce diatoms succession that increase lipids content).
(7) Following the reviewer's comment we transferred the tables to the main text and placed each appear after the relevant text.
Reviewer 4 Report
Comments and Suggestions for AuthorsThis manuscript present the sustainable aquafeed with economic benefits however it is in a bad written and bad format. So it would be great if the author could re-arrange the manuscript. Such as a workflow chart would hope to understand the design of this manuscript. Some table could convert to figure to present the results. Insert table to the corresponding text page so the reader can track down the results immediately and clearly.
Expand a bit about the results and short the discussion part.
The description of the methods is a bit confused. How to you set 335 fingerlings to 20 tanks (22±1 fish in each) (22*20=440 fishes in total)? And Fish tanks were randomly as-126 signed to the 4 experimental diets, with 5 replicate tanks for each diet. so where is the control?
Were there any fish died during the experiment? Where is this data?
I would suggest the author do a careful adjustment for the structure of the manuscript otherwise it is hard to catch reader's interests.
Comments on the Quality of English Language
Minor editing of English language required
Author Response
This manuscript present the sustainable aquafeed with economic benefits however it is in a bad written and bad format. So it would be great if the author could re-arrange the manuscript. Such as a workflow chart would hope to understand the design of this manuscript. Some table could convert to figure to present the results. Insert table to the corresponding text page so the reader can track down the results immediately and clearly.
Response: The sections in the manuscript were arranged according to the journal's guidelines and template. The sub-sections were arranged in logical chronological order. For example, in the methods section, the order is: section 2.2.1- the experimental diets which are the 'treatments'; section 2.2.2. - the feeding trial, where we provide data on the first experiment, its design and duration, the number of examined fish, the number of replicates, and the measured parameters; section 2.2.3. diet and nutrient digestibility - in this section we describe the second trial that was performed right after the feeding trial. As in the previous section, we provide data on the experiment (duration, replicates, measurements); sections 2.2.4-2.27 are dedicated to the description of the different analyses that were performed. Starting from (2.2.4) fish performances; (2.2.5) biochemical analyses; (2.2.6) digestibility analysis (this requires understanding the biochemical analyses from previous section; and (2.2.7) economic analyses - calculations that integrate results and data on costs of the feed ingredients. Finally (2.2.8), we provide a section on statistical analyses i.e., the statistical tests that were performed on the different datasets.
The tables were placed at the end of ms following the journal's guidelines and the template for manuscripts (downloaded from the journal's website).
Concerning the recommendation to convert tables to graphs, such conversion is problematic/undoable. In the current tables, the number of measured factors is relatively high. A graph for these results will be insufficient in terms of outlining the results since it will either require: a. more than two Y columns (e.g due to different measuring units for SGR, FCR, weight gain, survival) or b. high number of stakes (e.g. due to the great number of measured fatty acids). It should also be noted that the use of tables is common in manuscripts that present results on similar parameters.
Expand a bit about the results and short the discussion part.
Response While the results section provides a plain description of the results, the discussion section is the main course in this manuscript as it expands on the results by discussing their meaning, whether comparable or not to results from other studies, and some points for consideration with respect to the meaning of current results. We do not see which part or discussed studies the reviewer recommends to eliminate from the discussion.
The description of the methods is a bit confused. How to you set 335 fingerlings to 20 tanks (22±1 fish in each) (22*20=440 fishes in total)? And Fish tanks were randomly as-126 signed to the 4 experimental diets, with 5 replicate tanks for each diet. so where is the control?
Revised. Thank you for noticing these mistakes. Following the reviewer's comment we revised the relevant text. The number of fingerlings was revised to 445. The '4 experimental diets' was revised to 'the 4 types of diet (including the control)'.
Were there any fish died during the experiment? Where is this data?
Revised. Data on fish survival rate (in %) is provided in Table 4. This information was available also in the original draft.
I would suggest the author do a careful adjustment for the structure of the manuscript otherwise it is hard to catch reader's interests.
Please see the above explanations concerning the use of the journal's recommended template, following the author's guidelines regarding formats and section order, and the explanation of the chronology that we used in the different sections.
