The Effect of Water Spinach on the Water Quality, Antioxidant System, Non-Specific Immune Response, Growth Performance, and Carbon Balance in Red Tilapia Production
, Zhi-Qiang Lu 1, Liang-Sen Jiang 1, Yi-Fu Li 1 and Wen-Sheng Liu 1,3,4,*
Round 1
Reviewer 1 Report
The study investigated the compound cultivation model of red tilapia and water spinach and its influence on water quality, fish growth performance, fish immunity, and carbon sink. The study contributes to knowledge on the influence of aquatic plants on water quality and the health status of fish. However, I have quite a number of comments that I feel are necessary to improve the quality of this manuscript to fit the standards of MDPI Fishes.
Major comments
· The authors should revise the entire manuscript to correct all the grammatical errors and improve the sentence structure. The authors must take critical note of the tense used in the manuscript.
· The authors must use proper scientific language throughout the manuscript for clarity and cite more information in the discussion.
· The authors should re-analyze their data using the correct statistical test. I recommend using the independent sample t-test to compare the means of AP and AM instead of ANOVA
Minor comments
Introduction
· L60: Abbreviations must be written in full on their first mention in the manuscript
· L83 – L84: All scientific names must be in italics. Please revise the entire manuscript and write all scientific names in italics. Likewise, the authors should clearly write the scientific classification of red tilapia. For instance, order: Perciformes; family: Cichlidae...
· L88: salt tolerant
· L93: Change recipe to diet
· L128 – 133: The authors should delete this sentence from the introduction. This is part of the results from their study and not part of the main objectives of the research trial.
Methodology
· L139: I suppose the study was conducted in a protected structure like a greenhouse. Do the authors have any data on the temperature, relative humidity, or light intensity within the experimental area? It would be nice to report it if any.
· L171 – 172: I understand that water samples were collected once a week. Was this before or after feeding? Please clarify.
· L173 – 178: Were water temperature, pH, and dissolved oxygen measured on-site or after storage? Please write the correct names of the nitrogenous elements to represent the chemical formula. For example, NO2- –N is nitrite nitrogen not simply nitrite.
· L184 – 186: Ten randomly selected fish samples out of 200 fish per pond are not representative samples for measuring fish growth performance.
· L180 – 186: How was the final body weight, average daily gain, and specific growth rate calculated? The authors need to show equations for these
· L189: A blood sample was collected from the caudal vein ….
· L202: Red tilapia was collected before stocking and harvesting and dried at 110℃ to constant weight to determine its moisture content. The oven-dried samples were ground and screened and the powder was used to determine the carbon content.
· L216 – 218 In statistics, ANOVA is used to compare differences of means among more than two groups. In this study, the authors compared means of only two groups (i.e. AP and AM) hence ANOVA was not the correct statistical test. They should instead have used an independent sample t-test
Results
· L228: The authors must give the full name of the nitrogenous compound tested in the first mention and then their chemical symbols. Then they can proceed with the symbols.
· L243 – 247: The chemical symbols and abbreviations tell two different things. For example, the authors abbreviate NH4+ –N as ammonia nitrogen, NO2- –N as nitrite which is wrong. This should be corrected throughout the manuscript.
Discussion
· L296 – 298: Please provide a citation for this sentence. Also, rephrase with the correct scientific language of reporting previously published data.
· L312 – 314: Provide more references to support your statement.
· L359: Provide more references to support your statement
References
· Scientific names must all be written in italics
The authors should revise the entire manuscript to correct all the grammatical errors and improve the sentence structure. The authors must take critical note of the tense used in the manuscript.
Author Response
Dear reviewer:
Thank you for your letter and for the comments concerning our manuscript entitled “The compound cultivation model of red tilapia and water spinach is investigated into water quality, antioxidant, non-specific immune responses and carbon sink” (Manuscript ID: fishes-2616477). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have revised our manuscript. Point by point responses to your comments are listed below this letter. Attached please find the revised version and relevant document, which we would like to submit for your kind consideration.
Once again, thank you very much for your comments and suggestions. And we hope that the corrections will meet with approval. If you have any questions, please don’t hesitate to contact me.
Thank you and best regards.
Yours sincerely,
Wen-sheng Liu
College of Marine Sciences,
South China Agricultural University,
483 Wushan Street, Tianhe District,
Guangzhou 510642, PR China.
- mail: [email protected]
Response to the reviewer 1’ Comments:
- Summary
All comments have been revised in this manuscript using the “Track Changes” function. Thank you very much for taking the time to review this manuscript.
- Questions for General Evaluation
- Point-by-point response to Comments and Suggestions for Authors
Point 1: - L60: Abbreviations must be written in full on their first mention in the manuscript.
Response 1: It has been changed CO2(carbon dioxide). Thanks for your suggestions
Point 2: - L83–L84: All scientific names must be in italics. Please revise the entire manuscript and write all scientific names in italics. Likewise, the authors should clearly write the scientific classification of red tilapia. For instance, order: Perciformes; family: Cichlidae...
Response 2: We have revised it in the manuscript. Thank you.
Point 3: - L88: salt tolerant
Response 3: We have revised it in the manuscript. You can see it at line 101.
Point 4: - L93: Change recipe to diet
Response 4: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 106.
Point 5: -L128–133: The authors should delete this sentence from the introduction. This is part of the results from their study and not part of the main objectives of the research trial.
Response 5: We are very sorry for our negligence. We have delete this sentence from the introduction.
Point 6: - L139: I suppose the study was conducted in a protected structure like a greenhouse. Do the authors have any data on the temperature, relative humidity, or light intensity within the experimental area? It would be nice to report it if any
Response 6: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 144-149.
Point 7: - L171–172: I understand that water samples were collected once a week. Was this before or after feeding? Please clarify.
Response 7: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 183.
Point 8: -L173–178: Were water temperature, pH, and dissolved oxygen measured on-site or after storage? Please write the correct names of the nitrogenous elements to represent the chemical formula. For example, NO2-N is nitrite nitrogen not simply nitrite.
Response 8: We are very sorry for our negligence. we have revised it in the manuscript. You can see it at line 185.
Point 9: -L184–186: Ten randomly selected fish samples out of 200 fish per pond are not representative samples for measuring fish growth performance.
Response 9: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 206.
Point 10: - L180-186: How was the final body weight, average daily gain, and specific growth rate calculated? The authors need to show equations for these
Response 10: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 190-203.
Point 11: - L189: A blood sample was collected from the caudal vein …
Response 11: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 207.
Point 12: -L202: Red tilapia was collected before stocking and harvesting and dried at 110℃ to constant weight to determine its moisture content. The oven-dried samples were ground and screened and the powder was used to determine the carbon content.
Response 12: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 225-227.
Point 13: - L216–218 In statistics, ANOVA is used to compare differences of means among more than two groups. In this study, the authors compared means of only two groups (i.e. AP and AM) hence ANOVA was not the correct statistical test. They should instead have used an independent sample t-test
Response 13: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 239-249.
Point 14: L228: The authors must give the full name of the nitrogenous compound tested in the first mention and then their chemical symbols. Then they can proceed with the symbols.
Response 14: Thanks for your suggestions, we have revised it in the manuscript.
Point 15: L243–247: The chemical symbols and abbreviations tell two different things. For example, the authors abbreviate NH4+–N as ammonia nitrogen, NO2-–N as nitrite which is wrong. This should be corrected throughout the manuscript.
Response 15: Thanks for your suggestions, we have revised it in the manuscript.
Point 16: L296 - 298: Please provide a citation for this sentence. Also, rephrase with the correct scientific language of reporting previously published data.
Response 16: Thanks for your suggestions, we have revised it in the manuscript.
Point 17: L312–314: Provide more references to support your statement.
Response 17: Thanks for your suggestions, we have revised it in the manuscript.
Point 18: L359: Provide more references to support your statement
Response 18: Thanks for your suggestions, we have revised it in the manuscript.
- Response to Comments on the Quality of English Language
Point : The authors should revise the entire manuscript to correct all the grammatical errors and improve the sentence structure. The authors must take critical note of the tense used in the manuscript.
Response: Thanks for your comments, we have asked the polish service to revise the language of the manuscript, which you can see in the latest edition of the manuscript.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
the introduction should be written in a more harmonious way to allow the reader a clearer reading, the various concepts exposed must be presented in a clearer and more linear way.
Line 147= six 147 ponds; 3 for control and 3 for the experimental trial? not clear
Line 148= which commercial feed?
Line 189 = why were just the 5 % of the fish weight?
Line 192= Are 3 fish x pound representative for you?
Line 205= chapter unclear, revise
Line 207= repetitions
Line 246= figure 2, to small, quite difficult to read the showed results
Line 265= aquaponics system seems to be better than the aquatic monoculture system. Or is better or not, statistical data?
Line 266= figure 2, to small, quite difficult to read the showed results
Line 300= rephrase, the verb is missing
Line 313-322= unclear discussion of pH results
Line 348-352= Why wasn't this theory tested already in this experiment?
The discussion must be improved.
the English of the entire article needs to be revised as there are several errors (some reported) and many unclear sentences
Author Response
Dear reviewer:
Thank you for your letter and for the comments concerning our manuscript entitled “The compound cultivation model of red tilapia and water spinach is investigated into water quality, antioxidant, non-specific immune responses and carbon sink” (Manuscript ID: fishes-2616477). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have revised our manuscript. Point by point responses to your comments are listed below this letter. Attached please find the revised version and relevant document, which we would like to submit for your kind consideration.
Once again, thank you very much for your comments and suggestions. And we hope that the corrections will meet with approval. If you have any questions, please don’t hesitate to contact me.
Thank you and best regards
Yours sincerely,
Wen-sheng Liu
College of Marine Sciences,
South China Agricultural University,
483 Wushan Street, Tianhe District,
Guangzhou 510642, PR China.
- mail: [email protected]
Response to the reviewer 2’ Comments:
- Summary
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.
- Questions for General Evaluation
- Point-by-point response to Comments and Suggestions for Authors
Point 1: - Line 147= six 147 ponds; 3 for control and 3 for the experimental trial? not clear
Response 1: Thanks for your suggestions. We have revised it in the manuscript. You can see it at line 153.
Point 2: -Line 148= which commercial feed?
Response 2: Thanks for your suggestions. We have revised it in the manuscript. You can see it at line 155.
Point 3: -Line 189 = why were just the 5 % of the fish weight?
Response 3: Thanks for your suggestions. Our experiment is to serve the actual production. Feeding less affects the growth of fish, can not meet its growth requirements, affecting economic benefits. If we feed too often, it will affect the fish's stomach, if the fish do not finished, it will cause pollution to the water quality. Therefore, this is in line with the production practice.
Point 4: - Line 192= Are 3 fish x pound representative for you?
Response 4: Thanks for your suggestions. Here were 50 fish selected, and the specification was uniform, health and no damage, has been changed.
Point 5: Line 205= chapter unclear, revise
Response 5: Thanks for your suggestions. We have revised it in the manuscript. You can see it at line 216-222.
Point 6: - Line 207= repetitions
Response 6: We are very sorry for our negligence. we have revised it in the manuscript.
Point 7: -Line 246= figure 2, to small, quite difficult to read the showed results
Response 7: Thanks for your suggestions, we have revised it in the manuscript.
Point 8: Line 265= aquaponics system seems to be better than the aquatic monoculture system. Or is better or not, statistical data?
Response 8: Thanks for your suggestions, we have revised it in the manuscript.
Point 9: Line 266= figure 2, to small, quite difficult to read the showed results
Response 9: Thanks for your suggestions, we have revised it in the manuscript.
Point 10: - Line 300= rephrase, the verb is missing
Response 10: The + compare, the + compare, if the predicate verb is be, and the subject is not a pronoun, be is often omitted.
Point 11: - Line 313-322= unclear discussion of pH results
Response 11: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 332-334. The ranges of water variation for both systems, both within the normal growth range of tilapia
Point 12: - Line 348-352= Why wasn't this theory tested already in this experiment?
Response 12: Thanks for your suggestions. There are some deviations in the experiment and the theory, and the theory is not tested, but in the future experiments, we will pay attention to this test.
- Response to Comments on the Quality of English Language
Point : the English of the entire article needs to be revised as there are several errors (some reported) and many unclear sentences.
Response: Thanks for your comments, we have asked the polish service to revise the language of the manuscript, which you can see in the latest edition of the manuscript.
Author Response File: Author Response.pdf
Reviewer 3 Report
Brief summary
Dear Authors:
Following the COPE ethical guidelines for peer reviewers, I am pleased to submit the review report of the paper:
The compound cultivation model of red tilapia and water spinach is investigated into water quality, antioxidant, non specific immune responses and carbon sink.
I have read it carefully in its entirety, thanking the authors for their effort and dedication in its elaboration and consider the journal Fishes for its review and possible publication.
The Manuscript aims to:
investigate the effect of water spinach raft on water quality, antioxidant system, non-specific immune response, growth performance of red tilapia and the carbon balance of payments.
The work is very complete, since it involves the analysis of many study variables covering aspects of water quality, growth, antioxidant immune defenses in red tilapia under aquaponic system conditions with water spinach as a pond water remediator and agricultural production.
Water spinach is little known in many parts of the world as a nutrient-rich food, using it integrated into an aquaculture system only limited studies are reported.
Red tilapia has its market, popular in some regions of the world, but using it in conjunction with an aquaponic system could increase interest in its cultivation, for the added value of agricultural production and environmental benefits.
Specific comments:
The title with respect to the objective is suggested should be aligned.
In this case, the effect of water spinach in a Red Tilapia production system, I emphasize that there are many variables of analysis, which causes the title of the work to be very long. From the epistemological point of view, a title is recommended:
The object of study: the variables
The subject of study: who lives the problem.
The method: which in this case is ( the effect of ) but can be Relate, Evaluate, Impact of... correlation, relation etc. It depends on the type of research.
With these elements I hope it can help you to make the title a little shorter and more attractive. Maybe some variables are omitted in the title, but described in the methodology section,
What is the most important thing to contribute to the knowledge in this study?
I hope you take it as a constructive idea, the freedom of naming the paper is only of the authors.
Effect of water spinach on water quality, antioxidant system, non-specific immune response, growth performance and carbon balance in Red Tilapia Production ( 22 words)
This title is in accordance with the general objective.
The abstract
The term red tilapia I suggest to determine with accuracy if possible, which one they used (Oreochromis spp,) is very general and can have different results, the most common red tilapia are:
Red Florida: O. mossambicus albina x O. urolepis hornorum.
Red Aurea: O. aureus Roja.
Red Taiwanese: O. mossambicus Albina.
Red Singapore: O. mossambicus mutant.
Yumbo No.1: Red florida x O. niloticus.
Yumbo No.2: Red Florida USA x Red Florida Israel
The Red Florida genetic line (O. mossambicus x O. urolepis hornorum) is an excellent variety, which from the coloration of the photograph in Figure 1, would appear to be the one used. It tends to be orange in color.
Red Tilapia is characterized by its high adaptability to different production environments and food sources, being one of the most productive fish in aquaculture and well accepted in the market due to its nutritional and organoleptic characteristics. This aspect should be highlighted.
In the summary they indicate that the experiment lasted 9 weeks, 63 days, therefore at this stage we are in fry to juveniles, an aspect that should be clarified in the methodology and in the results, since the experiment was not a complete cycle.
Line 26 removal is the correct word.
Line 35 the conclusions should try to explain the effect of....
This paragraph is not supported by the results. "it improves the ecological benefits of carbon income and expenditure."
Keywords: Red tilapia; Ipomoea aquatica; The carbon balance of payments I suggest replacing them, since they are in the title.
Key Contribution:, is not appropriate, I suggest the authors to indicate precisely the removal of nutrients and each of the variables, remember that their objective is the effect of:
The original contribution of the experiment is: ……………………………………………………………
Studies already showed that water spinach is able to remove nutrients from water bodies, but their work was more to broad, that I would like them to highlight.
Introduction
In the introduction from line 44 to 55 you should include references to the documented Chinese problem that supports the wastewater problem with more empirical evidence.
After discharging the eutrophicational water into the environment, nitrogen and phosphorus enriched in water may make some plankton and algae grow wildly, and even lead to water bloom or red tide and other phenomena, resulting in insufficient dissolved oxygen in water and the death of fish (add references).
Line 54 For these problems, aquaponics system may be a potential strategy. (add references)
https://doi.org/10.1016/j.ibiod.2013.03.029
Line 56 to 76 has no reference, in an introduction it is appropriate that it should contain:
1 Is it focused on the problem?
2. Is it enjoyable and fruitful to read, does it summarize the letters and is it prolific in ideas?
3. Does it clearly state the reasons for conducting the study?
4. Does it state the premises on which the study is based?
5. Does it clearly define the objectives of the study?
6. Does it state the hypotheses that the study intends to demonstrate?
line 86 threat of NH4-N and NO2-N to fish health (add reference).
line 89... add this reference, it seems to be important.
According to Castillo (2006) Oreochromis mossambicus (red variety) as far as its origin is known, was created in Taiwan in 1968. from a hybrid of Oreochromis mossambicus with Oreochromis nilotica; four coloration patterns have been established, based on the presence and absence of red and pink as melanism in the body: pink, pink mottled with red, red and spotted with black.
https://ag.arizona.edu/azaqua/ista/reports/TILAPIAROJA2010.doc
line 87 to 98 should add references because they are talking about characteristics of red Tilapia that should be documented.
From line 99 to 118 only two references to talk about the aquatic plant, it is a theoretical framework that should be supported in the statements.
Lines 122 to 123 state that there are few data, what are these few data, do you have any reference to support this statement?
Line 124 is correct what they state, however, it is not the same species, they should focus on Red Tilapia. The darkbarbel catfish is another species. There are many studies on tilapia, I suggest adding them.
Line 124 to 130 References 17, 18, 19, and 20 are other species, probe on tilapia, it is better to have that evidence of it, for later discussion, how will you discuss your results contrasting with other species? I consider that it is not appropriate.
From 131 to 137 final paragraph of the introduction, normally it ends with an objective of the research, which is supported by the introduction, the objective is different from that of the abstract, you should unify it, you can raise working hypotheses, advance results.
The authors guide states; "briefly mention the main objective of the work and highlight the main conclusions. As far as possible, make the introduction understandable to scientists outside your field of research".
Therefore, it is not wrong to advance conclusions, but these should motivate the reader to continue reading, the most read part of an article is the abstract and the introduction. Therefore, I encourage you to improve it.
Methodological inaccuracies: Recommendations for the methodology
Did you provide all the necessary information about the populations studied and the products used (doses, origin)?
Did you include all the methods used in the study?
Did you describe them in detail?
Did you correctly cite the methods?
Are the statistical procedures rigorous?
Is the use of parametric and non-parametric methods consistent in the description of data and their statistical treatment?
These are reflection questions that support your work.
Correctly defining the species of red Tilapia used, describing by weight that they are juvenile red Tilapia (Oreochromis mossambicus x Oreochromis nilotica) is an example. Because they do not indicate which one it is in the methodology.
18.54±1.78g initial weight.
Line 148 Each pond contained 200 red tilapia fed twice daily with commercial feed.
Which commercial feed? Tilapia feed with 38% protein and fat? Pellet size?
The pellet size should be approximately ?08 to 2.5 mm, and why is the ration only 2 times a day?
Is it what your feed supplier indicates? No, for the age it should be more times a day.
How much percent of their daily biomass?
It is important to report the stocking density of juvenile tilapia.
Please detail this information.
ir compressors (HG-200; Shenshen, China) Capacity in HP, Kw or CFM ? indicate. Compressor or blower?
More characteristics are needed, remember that any methodology must be replicable.
The equipment and instruments used to perform the work must be properly described. Following the authors' guide. Example: (YSI-650 Inc., Yellow Spring Instruments, Yellow Springs, OH, USA),
Line 153 to 155 Ethical Statement (example)
The Advanced Research Board of the Department of Zoology, The University of Lahore, sub campus Sargodha Punjab, Pakistan, has approved the current study, under the trial registration number UOLS/FSH/0652 and the research investigation was accomplished according to the ethical consideration of the European Legislation (Animal rights).
Line 159 (patent number: ZL 201620287095.4) could not be found, so I suggest describing the model in the manuscript. With dimensions and characteristics, I understand that perhaps the patent is protected, but from the methodological point of view it is necessary to know the dimensions of the system through a Figure. Or failing that the web link.
Line 175 Why do you only obtain a weekly sample, if in the daily routine of a farm the physicochemical parameters are taken daily?
Do I agree with the mention that for physicochemical variables standard methods are applied, but no special instrument was used?
Line 186 Ten fish were randomly selected from each pond to measure their body weight. During the experiment
Do you consider this sample size to be appropriate, and why?
If you have 200 tilapia per tank, do you consider this a representative sample?
line 186 and 189 repeat the same thing
line 192 Antioxidant status and non-specific immune responses only 3 tilapia per tank, same questions,
Do you consider this sample size to be appropriate, why?
If you have 200 tilapia per tank, do you consider this a representative sample?
201 to 203 more detailed information on the kit.
Line 208 an element analyzer to determine the carbon content. Which one? please write the equipment.
Line 213 TOC analyzer, please describe appropriately.
Line 220 Mean SEM (what is SEM?) and Soffware (SPSS Inc., Chicago, IL, U.S.A.)
Line 223 Figure 2, you can split it to increase the quality 300 DPI, for example, when you write about the red tilapia, place the figure, when you describe the system, place the image, do not group them together, place them strategically in the manuscript.
Authors are strongly recommended that their methodology be clear and replicable, hence the importance of reviewing empirical evidence and similar works.
Results
Recommendation for conclusion and for support.
Is the parallelism between the presentation of results in the text and the presentation of data in tables and figures perfect?
Does the order of presentation of the different types of results follow a logical order?
Have you highlighted the star results?
Is it clear in all comparisons which values are compared and which test is used for comparison?
Is the use of descriptive parameters and tests consistent with the sample sizes and type of data distribution?
Do you provide the p value in the text or illustrations when the test is significant?
Can you present the data in a more concise way?
Lines 229 to 232 repeat part of the methodological section, the authors should go in order reporting the results:
Figure 2 is too small, they should enlarge the size, in a printed version it would not be understood. I suggest improving its size and resolution.
Just write half a page of the analysis of 8 water quality variables. I am sure they can better explain the behavior, not only by stating the significant differences, because the variables behave in a certain way.
Figure 3. Same comments as Figure 2.
Discussion
Recommendations for discussion of the results:
Start by presenting the answer to the main question stated in the introduction.
Does it deduce applications or implications of your answer?
Does it highlight the novelty of the work by explaining what the conclusions reached add to existing knowledge?
Do you claim priority if appropriate?
Do you explain why the answer follows from the results, why it is reasonable, and how it fits within existing knowledge?
Do you use scientific hypotheses rigorously?
Do you not reiterate the results?
Is the manuscript clear, relevant to the field, and presented in a well-structured manner?
These are questions for your reflection and support.
line 304 reference to the end of paragraph. Grow normal and
line 305 to 310 references, this because they are water chemistry concepts, which is documented.
Line 314 reference pH optimum for Red Tilapia.
Line 325 reference 31 is not appropriate, since it talks about another species, I recommend the authors to include a table with the optimal parameters for the development of red tilapia and they can better discuss the results.
Line 332 to 334 References 16 and 33 are for other species, they should look into the many articles on aquaponics with tilapia. You cannot speculate on the science, the results and evidence in aquaponic systems should suggest a possible answer.
lines 336 to 342 are references of plants, but this work talks about water spinach, and aquaponics systems, so you should add references of it, the other plants are not of interest, because the work is focused on a specific plant.
Line 381 These results suggest that water spinach raft could improve the stress resistance of co-cultured red tilapia. This statement cannot be attributed to the plant, but rather to the effect on water quality due to water spinach. If they have evidence that indicates with certainty that a plant can, prove it.
lines 384 to 400 there is no reference that would dispute their results.
Line 402 focus on Tilapia.
line 409 do not use the word speculate, in science it is written, it is affirmed with evidence, (the results indicate with support of empirical evidence that ........
Conclusions, Recommendation for conclusions:
Degree of linkage to the objectives.
Degree of integration of the theoretical and application framework.
Discussion raised with respect to the results obtained.
Derivation of normative or explanatory processes on reality.
Clarification of the limits of the study and proposals for new studies.
These are questions for reflection and support.
The conclusions that the authors propose do not contain sufficient and conclusive elements of their research objectives. These should be rethought, note that they have many study variables, it is not possible to generalize and recommend the application of water spinach and red tilapia with only 60 days, they should suggest future lines of research, where is the carbon balance of payments?
For example:
Crop densities
Productivity in Kg/m3
Value added by agricultural production
Production costs
Pond spinach coverages
Evaluation of system sustainability
Dear editors:
Unfortunately, the methodology is not clear, the study period is very short, this paper I recommend to be edited as a short communication, because of the period of the experiment. The authors should address the suggestions, the research is interesting and relevant, but I consider that its sample size and sampling periods are not appropriate for a research article with sufficient statistical evidence, since it was evaluated for 63 days. These are partial, original results, but in the juvenile stage of red Tilapia, they cannot be generalized to a commercial farm.
The references used generally refer to other species; the authors should investigate further in works with aquaponic water spinach and red Tilapia, for an adequate discussion.
Are the references cited mostly recent (within the last 5 years) and relevant publications?
Some are not appropriate; however they should focus on the ample existing evidence for aquaponics, water spinach and red tilapia, it is not necessary to analyze other species.
Does it include an excessive number of author cites?
No.
Is the manuscript scientifically sound and is the experimental design appropriate for testing the hypothesis?
Should be improved from the introduction to the conclusion, the experiment is too short.
Are the results of the manuscript reproducible according to the details provided in the methods section?
No, the experimental protocol is not clear, with the information the methodology is not replicable.
Are the figures/tables/pictures/schemes appropriate, do they show the data correctly, are they easy to interpret and understand?
The tables are fine, but the visual quality of the graphs should be improved, as putting them together in a single image makes them small and they must be enlarged to see them, and resolution is lost.
Are the data interpreted adequately and coherently throughout the manuscript?
They should be more organized, when presenting your results and discussion. Since the discussion is in another section.
Are the conclusions consistent with the evidence and arguments presented?
They should be improved, depending on your study variables.
Evaluate the ethics statements and data availability statements to ensure that they are adequate.
They are not stated in the manuscript, but they should be improved and a section should be devoted to them.
The importance and strength of the proposed hypotheses: Not presented.
The suitability and feasibility of the experimental and analytical methodology: Should be improved.
Whether sufficient detail has been provided to replicate the proposed experimental procedures and analysis; Unfortunately it was not well detailed.
Whether there is sufficient outcome-neutral hypothesis testing, including positive controls and quality controls: Not stated.
Author Response
Dear reviewer:
Thank you for your letter and for the comments concerning our manuscript entitled “The compound cultivation model of red tilapia and water spinach is investigated into water quality, antioxidant, non-specific immune responses and carbon sink” (Manuscript ID: fishes-2616477). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have revised our manuscript. Point by point responses to your comments are listed below this letter. Attached please find the revised version and relevant document, which we would like to submit for your kind consideration.
Once again, thank you very much for your comments and suggestions. And we hope that the corrections will meet with approval. If you have any questions, please don’t hesitate to contact me.
Thank you and best regards.
Yours sincerely,
Wen-sheng Liu
College of Marine Sciences,
South China Agricultural University,
483 Wushan Street, Tianhe District,
Guangzhou 510642, PR China.
- mail: [email protected]
Response to the reviewer 3’ Comments:
- Summary
Thank you very much for taking the time to review this manuscript. Please find the detailed responses below and the corresponding revisions/corrections highlighted/in track changes in the re-submitted files.
- Questions for General Evaluation
- Point-by-point response to Comments and Suggestions for Authors
Point 1: - The title with respect to the objective is suggested should be aligned.
Response 1: Thanks for your suggestions, we have revised the title.
Point 2: The term red tilapia I suggest to determine with accuracy if possible
Response 2: We have revised it in the manuscript. Thank you.The red tilapia species have been refined. You can see it at line 16.
Point 3: - The Red Florida genetic line (O. mossambicus x O. urolepis hornorum) is an excellent variety, which from the coloration of the photograph in Figure 1, would appear to be the one used. It tends to be orange in color.
Response 3: We have revised it in the manuscript. You can see it at line 19.
Point 4: - In the summary they indicate that the experiment lasted 9 weeks, 63 days, therefore at this stage we are in fry to juveniles, an aspect that should be clarified in the methodology and in the results, since the experiment was not a complete cycle.
Response 4: Although the whole experiment was only 63 days, under the premise of the closed water body, the water quality between the experimental and control groups was significantly different, and there were significant differences in tilapia growth and non-specific immune indicators. We verified the experimental results and implemented them from the aspect of economic cost.
Point 5: -Line 26 removal is the correct word.
Response 5: We have revised it in the manuscript. Thank you. You can see it at line 29.
Point 6: - Line 35 the conclusions should try to explain the effect of....
Response 6: There are some deviations in the experiment and the theory, and the theory is not tested, but in the future experiments, we will pay attention to this test.
Point 7: -Red tilapia; Ipomoea aquatica; The carbon balance of payments I suggest replacing them, since they are in the title.
Response 7: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 44.
Point 8: -Key Contribution:, is not appropriate, I suggest the authors to indicate precisely the removal of nutrients and each of the variables, remember that their objective is the effect of:
Response 8: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 47-52.
Point 9: -In the introduction from line 44 to 55 you should include references to the documented Chinese problem that supports the wastewater problem with more empirical evidence.
Response 9: Thanks for your suggestions, we have revised it in the manuscript.
Point 10: - Line 54 For these problems, aquaponics system may be a potential strategy. (add references)
https://doi.org/10.1016/j.ibiod.2013.03.029
Response 10: Thanks for your suggestions, we have revised it in the manuscript.
Point 11: - Line 56 to 76 has no reference, in an introduction it is appropriate that it should contain:
Response 11: Thanks for your suggestions, we have revised it in the manuscript.
Point 12: -line 86 threat of NH4-N and NO2-N to fish health (add reference).
Response 12: Thanks for your suggestions, we have revised it in the manuscript.
Point 13:line 89... add this reference, it seems to be important.
Response 13: Thanks for your suggestions, we have revised it in the manuscript.
Point 14: line 87 to 98 should add references because they are talking about characteristics of red Tilapia that should be documented.
Response 14: Thanks for your suggestions, we have revised it in the manuscript.
Point 15: From line 99 to 118 only two references to talk about the aquatic plant, it is a theoretical framework that should be supported in the statements.
Response 15: Thanks for your suggestions, we have revised it in the manuscript.
Point 16: Lines 122 to 123 state that there are few data, what are these few data, do you have any reference to support this statement?
Response 16: Thanks for your suggestions, we have revised it in the manuscript.
Point 17: Line 124 is correct what they state, however, it is not the same species, they should focus on Red Tilapia. The darkbarbel catfish is another species. There are many studies on tilapia, I suggest adding them.
Response 17: Thanks for your suggestions, we have revised it in the manuscript.
Point 18: Line 124 to 130 References 17, 18, 19, and 20 are other species, probe on tilapia, it is better to have that evidence of it, for later discussion, how will you discuss your results contrasting with other species? I consider that it is not appropriate.
Response 18: Thanks for your suggestions, we have revised it in the manuscript.
Point 19: -From 131 to 137 final paragraph of the introduction, normally it ends with an objective of the research, which is supported by the introduction, the objective is different from that of the abstract, you should unify it, you can raise working hypotheses, advance results.
Response 19: We have revised it in the manuscript. Thank you.
Point 20: Line 148 Each pond contained 200 red tilapia fed twice daily with commercial feed.
Response 20: Fenghua tilapia compound feed, floating water particle type. Fish size 1, about 2-3㎜in size, suitable for fish 7-12cm in length.（≥33% crude protein. We have revised it in the manuscript. Thank you. You can see it at line 155.
Point 21: - Is it what your feed supplier indicates? No, for the age it should be more times a day.
Response 21: Is directed by the feed supplier. Our experiment is to serve the actual production. Feeding less affects the growth of fish, can not meet its growth requirements, affecting economic benefits. If we feed too often, it will affect the fish's stomach, if the fish do not finished, it will cause pollution to the water quality. Therefore, this is in line with the production practice.
Point 22: - In the summary they indicate that the experiment lasted 9 weeks, 63 days, therefore at this stage we are in fry to juveniles, an aspect that should be clarified in the methodology and in the results, since the experiment was not a complete cycle.
Response 22: Daily feeding was 2% of fish weight, documented in the literature and consistent with production practice.
Point 23: -ir compressors (HG-200; Shenshen, China) Capacity in HP, Kw or CFM ? indicate. Compressor or blower?
Response 23: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 160.
Point 24: - Line 35 Line 153 to 155 Ethical Statement (example)
Response 24: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 162.
Point 25: -Line 159 (patent number: ZL 201620287095.4) could not be found.
Response 25: We are very sorry for our negligence. we have revised it in the manuscript. You can see it at line 167.
Point 26: -Line 175 Why do you only obtain a weekly sample, if in the daily routine of a farm the physicochemical parameters are taken daily?
Response 26: If monitored daily, the water quality indicators change little and can adversely affect the fish.
Point 27: -Line 186 Ten fish were randomly selected from each pond to measure their body weight. During the experiment
Response 27: Here were 50 fish selected, and the specification was uniform, health and no damage, has been changed. You can see it at line 192.
Point 28: - line 186 and 189 repeat the same thing
Response 28: We are very sorry for our negligence. we have revised it in the manuscript.
Point 29: - line 192 Antioxidant status and non-specific immune responses only 3 tilapia per tank, same questions
Response 29: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 196.
Point 30: -201 to 203 more detailed information on the kit.
Response 30: Thanks for your suggestions. we have added it in the manuscript.
Point 31: Line 208 an element analyzer to determine the carbon content. Which one? please write the equipment.
Response 31: Thanks for your suggestions. we have revised it in the manuscript. You can see it at line 232.
Point 32: Line 213 TOC analyzer, please describe appropriately.
Response 32: Thanks for your suggestions. we have revised it in the manuscript. You can see it at line 233.
Point 33: Line 220 Mean SEM (what is SEM?) and Soffware (SPSS Inc., Chicago, IL, U.S.A.)
Response 33: Thanks for your suggestions. we have revised it in the manuscript. You can see it at line 239-249.
Point 34: Line 223 Figure 2, you can split it to increase the quality 300 DPI, for example, when you write about the red tilapia, place the figure, when you describe the system, place the image, do not group them together, place them strategically in the manuscript.
Response 34: I’m sorry that I don't quite understand what you mean.
Point 35: Lines 229 to 232 repeat part of the methodological section, the authors should go in order reporting the results:
Response 35: Thanks for your suggestions, we have revised it in the manuscript.
Point 36: Figure 2 is too small, they should enlarge the size, in a printed version it would not be understood. I suggest improving its size and resolution.
Response 36: Thanks for your suggestions, we have revised it in the manuscript.
Point 37: Just write half a page of the analysis of 8 water quality variables. I am sure they can better explain the behavior, not only by stating the significant differences, because the variables behave in a certain way.
Response 37: Thanks for your suggestions, we have revised it in the manuscript.
Point 38: Figure 3. Same comments as Figure 2.
Response 38: Thanks for your suggestions, we have revised it in the manuscript.
Point 39: line 304 reference to the end of paragraph.
Response 39: Thanks for your suggestions, we have revised it in the manuscript.
Point 40: line 305 to 310 references, this because they are water chemistry concepts, which is documented.
Response 40: Thanks for your suggestions, we have revised it in the manuscript.
Point 41: Line 314 reference pH optimum for Red Tilapia.
Response 41: Thanks for your suggestions, we have revised it in the manuscript.
Point 42: Line 325 reference 31 is not appropriate, since it talks about another species, I recommend the authors to include a table with the optimal parameters for the development of red tilapia and they can better discuss the results.
Response 42: Thanks for your suggestions, we have revised it in the manuscript.
Point 43: Line 332 to 334 References 16 and 33 are for other species, they should look into the many articles on aquaponics with tilapia. You cannot speculate on the science, the results and evidence in aquaponic systems should suggest a possible answer.
Response 43: Speculate that the word is indeed not used here and has been changed. Although the references here are not for tilapia, the similar physiological and biochemical processes are the same in aquaculture production, and our team has done a lot of experiments on tilapia fish dish symbiosis.
Point 44: lines 336 to 342 are references of plants, but this work talks about water spinach, and aquaponics systems, so you should add references of it, the other plants are not of interest, because the work is focused on a specific plant.
Response 44: Thanks for your suggestions, we have revised it in the manuscript.
Point 45: Line 381 These results suggest that water spinach raft could improve the stress resistance of co-cultured red tilapia. This statement cannot be attributed to the plant, but rather to the effect on water quality due to water spinach. If they have evidence that indicates with certainty that a plant can, prove it.
Response 45: Thanks for your suggestions, we have revised it in the manuscript.
Point 46: lines 384 to 400 there is no reference that would dispute their results.
Response 46: Thanks for your suggestions, we have revised it in the manuscript.
Point 47: Line 402 focus on Tilapia
Response 47: Thanks for your suggestions, we have revised it in the manuscript.
Point 48: line 409 do not use the word speculate, in science it is written, it is affirmed with evidence, (the results indicate with support of empirical evidence that ........
Response 48: Thanks for your suggestions, we have revised it in the manuscript. You can see it at line 355.
Point 49: Conclusions, Recommendation for conclusions
Response 49: This experiment was completed within 63 days. Red tilapia grew from fry to juvenile, but did not reach the commercial fish stage, but in actual production, this system could continue to operate. Because water cabbage can be harvested repeatedly and the water quality can be guaranteed, the young fish can grow to the size of the commercial fish, which is in line with the actual production.
- Response to Comments on the Quality of English Language
Response: Thanks for your comments, we have asked the polish service to revise the language of the manuscript, which you can see in the latest edition of the manuscript.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
All my comments have been answered satisfactorily
Author Response
Dear reviewer:
I am writing the letter to express my gratitude. Thank you for your letter and for the comments concerning our manuscript entitled “Effect of water spinach on the water quality, antioxidant system, non-specific immune response, growth performance, and carbon balance in Red Tilapia Production ” (Manuscript ID: fishes-2616477). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research.
Thank you for your high evaluation of this manuscript. We are all looking forward to the manuscript being published soon.
Thank you and best regards.
Yours sincerely,
Wen-sheng Liu
College of Marine Sciences,
South China Agricultural University,
483 Wushan Street, Tianhe District,
Guangzhou 510642, PR China.
- mail: [email protected]
Author Response File: Author Response.pdf
Reviewer 2 Report
I thank the authors for having made the necessary corrections in the text, small corrections are still necessary, especially in the images which are not entirely correct in my opinion.
Line 155 : producer? Country?
line 170 : italic
Figure 2: Do the bars in the graph represent standard deviations? nothing is reported in the explanation of the graph
Figure 3: the cuts in the figure make unclear and not visible the results. Do the bars in the graph represent standard deviations? nothing is reported in the explanation of the graph
I tried to look for the protocols of the kits mentioned that you purchased from Nanjing Jiancheng Institute, 216 Nanjing, but without success, consider providing more information.
There is a clear improvement in the text
Author Response
Dear reviewer:
Thank you for your letter and for the comments concerning our manuscript entitled “The compound cultivation model of red tilapia and water spinach is investigated into water quality, antioxidant, non-specific immune responses and carbon sink” (Manuscript ID: fishes-2616477). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have revised our manuscript. Point by point responses to your comments are listed below this letter. Attached please find the revised version and relevant document, which we would like to submit for your kind consideration.
Once again, thank you very much for your comments and suggestions. And we hope that the corrections will meet with approval. If you have any questions, please don’t hesitate to contact me.
Thank you and best regards.
Yours sincerely,
Wen-sheng Liu
College of Marine Sciences,
South China Agricultural University,
483 Wushan Street, Tianhe District,
Guangzhou 510642, PR China.
- mail: [email protected]
Author Response File: Author Response.pdf
