PONE-D-23-43259

An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758)

PLOS ONE

Dear Dr. Naeem,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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We look forward to receiving your revised manuscript.

Kind regards,

Amit Ranjan, Ph.D.

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Partly

Reviewer #3: Yes

Reviewer #4: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: I Don't Know

Reviewer #3: Yes

Reviewer #4: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: No

Reviewer #3: Yes

Reviewer #4: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: No

Reviewer #3: No

Reviewer #4: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript entitled “An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758)” explores the best or most effective levels of dietary protein to enhance the growth and influence the body composition of walking catfish. This manuscript lacking the necessary details like dietary ingredients used for diet preparation, protein source etc. I feel this paper is not suitable to be published on the PLOS ONE in the current state. I have noted some major comments as follows:

1. I would like to emphasize the importance of explicitly disclosing the dietary ingredients employed in the diet preparations outlined in this study. Additionally, it is crucial for the authors to clearly specify the protein source utilized in the study. This information is essential for ensuring transparency, reproducibility, and a comprehensive understanding of the experimental conditions. Please provide a detailed account of the dietary components and protein source to strengthen the integrity of the research

2. I suggest that the authors also include the proximate compositions of the experimental diets. Providing this information would add valuable detail to the study, aiding in the understanding of nutritional aspects and ensuring transparency for readers.

3. It would be beneficial to provide the instrument names, manufacturers, and any relevant specifications in the Materials and Methods section.

4. In line 113-114, the authors mention drying temp at 80ºC for water content analysis. However, it is essential to clarify the duration of this drying process.

5. I suggest the authors reconsider the use of the difference method for calculating protein content in the manuscript. While this method provides an approximate estimate, for more accurate and reliable results, it is advisable to employ established laboratory analysis method such as the Kjeldahl method. These methods are widely accepted for protein determination and would enhance the precision and credibility of the protein content reported in the study.

6. I suggest that the authors consider investigating protein digestibility as part of this study. Including an analysis of protein digestibility would provide valuable insights into the bioavailability of dietary proteins and contribute to a more comprehensive understanding of the nutritional aspects under investigation.

7. On page 9, line 287, there appears to be a typo in the scientific name. It should be 'Ctenopharyngodon idella' instead of 'Ctenophyrngodon Idella.' Please correct this to ensure accuracy in the scientific nomenclature throughout the manuscript.

8. There few typesetting errors throughout the manuscript that should be corrected accordingly

Reviewer #2: The main purpose of the article appears to be to investigate the effects of varying levels of dietary protein on the survival, growth parameters, and proximate composition of Clarias batrachus, a commercially important food fish in Pakistan. While the study offers some insights, there are notable shortcomings that raise questions about its suitability for publication in its current form. My reasons are as follows:

1. Insufficient novelty and significance. The researchers evaluate different crude protein percentages in the diets and assess their impact on factors such as weight gain, daily growth rate, protein efficiency ratio, and body composition, which are merely the most fundamental parameters used to evaluate feed formulations or to confirm the appropriate proportions of certain ingredients, and the work has already been done in closely related species. Since the experimental limitations and the lack of further investigation, a thorough and deep discussion could not be provided in the manuscript. Even the current data were not properly analyzed and discussed. It only indicated whether the results aligned or diverged from previous studies, without providing an explanation for the observed outcomes. To foster a more comprehensive discussion on this topic, additional research should be undertaken to explore factors such as enzyme activity, oxidative stress, gut microbiota, and blood physiological indicators, even immune response level.

2. The introduction was not well written. No former studies about the function of crude proteins (or other nutritional ingredients) in upgrading biological traits in cultivated fish were introduced, which had already been widely studied and was supposed to be the most important information in this part.

3. The authors should also provide more detailed information on the statistical methods used, as well as any potential limitations and sources of bias in their study.

4. Need thorough language editing.

Reviewer #3: The present manuscript reported a well-defined experimental design that documented using simple and solid data (statistically confirmed), which is the best quantity of dietary protein in walking catfish farming.

The work is generally written in an understandable way, however there are several parts that are more confusing and deserve a grammatical and syntactic revision. I report here a list of lines that should be reformulated to better clarify the concepts expressed:

Lines 40-42; 60-61; 71-73; 200-206; 258-264.

Important materials that must be provided in this manuscript concern: a complete table regarding the composition of the diets, with important emphasis on the origin (animal/vegetable) of the protein source used, and its amino acid composition.

Along the text I also encountered several errors and inaccuracies. I reported them below:

Line 14: "Clarias batrachus is commercialy..." should be corrected as "Clarias batrachus is a commercially..."

Line 17: the symbol @ should be corrected with the symbol ≈ or ±.

Line 31: "insignificant correlation" should be changed to "non-significant correlation".

Line 47: the term "realized" is not appropriate, I suggest to use "considered" or "represent".

Line 53: "A vital issue" is not properly appropriate in this context, I suggest to change it.

Line 68: "Henceforth" should be changed to "Therefore".

Lines 75-78: I suggest to reformualte the sentence in this way: "Fish proximate body composition constituents (fat, protein, water, organic content and ash) are influenced by diet, feed rate, sex, genetic strain, age, species and also by changing body size and condition factor [26-28].

Line 93: the same correction reported for line 17.

In material and methods should be also provided information regarding the illumination (light/dark cycle) during the trial.

Line 129: the same correction reported for line 31.

Line 133: "Significant highest" should be changed to "Significantly highest".

Lines 150-152: I suggest to reformualte the sentence in this way: "Mean value of water, ash, fat and protein contents (% wet mass) were ranged from 74.10±0.31% to 79.23±0.52%, 3.12±0.07% - 4.68±0.05%, 3.90±0.06% - 4.43±0.05% and 13.09±0.58% - 16.79±0.27% in the studied treatments..." to avoid repetitions.

Line 155: "and T6 than T4" should be changed to "and T6 than for T4".

Lines 201-202: I suggest to reformualte the sentence in this way: "the present experiment was found similar to that previously described by Tadesse [30]" to avoid repetitions.

Line 207: "is a vital gauge".

Line 210: Although FCR value between 1.2 and 1.5 represent a good indicators, it could not be used as absolute standard in all fish species, as it can change according to several culturing factors. In addition the reference [33] reported this range in tilapia. I suggest to reformulate this sentence.

Line 216: "animal ingredients" it should be clarified in M&M, providing further information about this source.

Line 281: there is a repetition of "in".

REFERENCES should be revised and checked accordingly to the journal requirements as I encountered some errors, such as Line 392, 400 and 416.

Table 1 and 2: It is not an error, however I suggest to substitute the title of the last column from "Sig." to "p-value", and the ".000" with "< .001".

In Table 2 the caption is missing.

Reviewer #4: An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758)

This study (PONE-D-23-43259) examines the repercussions of varying protein levels in the diet of Clarias batrachus, a commercially significant food fish in Pakistan. The research assesses the influence of different protein levels on the survival, growth parameters, and proximate composition of C. batrachus throughout a 90-day period. While acknowledging the quality of your paper, I have some suggestions to enhance your work.

- I recommend delving into further research to explore the lasting effects of employing the optimal 40% crude protein diet on C. batrachus, considering aspects related to reproduction and overall health.

- Additionally, it is advisable to investigate whether environmental factors, such as water quality or temperature, played a contributory role in the observed outcomes, and to evaluate the necessity of incorporating these factors into future studies.

- Furthermore, I propose that the author undertake a comparative analysis of the findings from this study with analogous research on other fish species to enrich the discussion section.

- Moreover, conducting a comprehensive economic analysis would contribute to evaluating the cost-effectiveness of implementing the 40% crude protein diet in aquaculture in comparison to alternative protein levels.

- Finally, I suggest reflecting on strategies to effectively disseminate the discoveries of this study to aquaculture practitioners, farmers, and stakeholders. Exploring avenues for promoting optimal dietary practices within these target audiences could be beneficial.

I ask the authors to edit and respond to these points:

1. Some sentences were not clear, you must formulate them correctly. Yet, English should be improved and reviewed by a native speaker.

2. You should be precise about what factors might contribute to the 100% survival rate across all treatments.

3. Could the study provide insights into why treatment with 40% crude protein (T4) resulted in the highest growth parameters for the studied specie?

4. What implications do the variations in water, ash, fat, and protein content have for the nutritional value of C. batrachus in different treatments?

5. How might the observed differences in body composition across treatments impact the quality of the fish as a food source?

6. Why did the treatment with 40% crude protein (T4) exhibit the best Feed Conversion Ratio (FCR)? Are there specific physiological or metabolic reasons for this result?

7. How does body size affect the body composition of C. batrachus?

8. In what ways does the condition factor correlate with body size, and why were these correlations mostly insignificant?

9. How can the findings of this study be practically applied in aquaculture operations, especially in formulating optimal diets for C. batrachus?

10. Are there any limitations or challenges in implementing the recommended 40% crude protein diet on a commercial scale?

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Reviewer #1: Yes: Nitesh Kumar Yadav

Reviewer #2: No

Reviewer #3: Yes: Federico Moroni

Reviewer #4: Yes: Sami MILI

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PONE-D-23-43259R1An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758)PLOS ONE

Dear Dr. Naeem,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Apr 25 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Amit Ranjan, Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #3: (No Response)

Reviewer #4: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #3: Yes

Reviewer #4: Yes

********** 

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #3: Yes

Reviewer #4: Yes

********** 

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #3: Yes

Reviewer #4: Yes

********** 

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #3: Yes

Reviewer #4: Yes

********** 

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #3: The authors resolved several errors and missing information during the firast round of review. However, there are few things that should be adressed.

Line 64-65: The correction made did not include "may BE higher". In addition, this part seems a bit confusiong, the author should clarify the concept better. FCR is a commonly used measure of conversion which is commonly used over the entire production life of a fish, and obviously, the amount of feed changes during this period, but this does not invalidate its importance.

Line 107: The two new references 29 and 30 have incorrect numbers referring with the list of references, please check them. In addition, although accurate, the reference Preston et al.,2016, used for the calculation of proximate composition, does not include all the information for the correct evaluation of the ingredients listed in Table 1. Please provide further details or change the reference.

Line 218: "feeding fish WITH 30%..."

Table 1. There is no indication about the unity of measurement of the ingredients. It must be indicated, together with the acronym CMC, in the caption.

Furthermore, regarding the reported CP values, there are inconsistencies between the values and the name of the experimental diets for CP-35; CP-40; CP-45 and CP-50 (for these diets the effective amount of crude protein is lower). Since this part represents the core of the article and the author in the discussion and conclusion sections refers to the diet as the effective amount of crude protein, this information needs to be clarified and corrected.

Reviewer #4: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #3: Yes: Federico Moroni

Reviewer #4: Yes: Sami MILI

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[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

An approach to optimizing dietary protein to growth and body composition in walking catfish, Clarias batrachus (Linneaeus, 1758)

PONE-D-23-43259R2

Dear Dr. Naeem,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Amit Ranjan, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: