Effects of Different Densities of Sea Grape Caulerpa lentillifera on Water Quality, Growth and Survival of the Whiteleg Shrimp Litopenaeus vannamei in Polyculture System
Round 1
Reviewer 1 Report
This manuscript presents an experimental study about the effects of sea grape on the water quality, growth and survival of whiteleg shrimp in polyculture systems. Please, find bellow my comments:
- The introduction section can be improve with a better literature review and a better description of the sate of the art
- Also, the contribution of this study to the state of the art should be highlight
- It can help the readers if the authors present a table with the initial conditions in Section 2, a table is easier to read than the information in different parts of the text, in my opinion...
- The authors collected data at 7:00 and 14:00, why they choose those hours? For example, if they measure at 17:00 or 20:00, what are the expected differences related to the measures at 14:00?
- In this study, it is important the light intensity? If yes, did the authors tried to study the influence of different light intensities?
Author Response
All comments from reviewer 1 have been implemented in the attached document.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This report illustrated the effects of macroalgae co-culture on the whiteleg shrimp production. The experiment is well-designed, and the data interpretations are reasonable. I consider this paper be accepted for publication in fishes after revision. The specific comments and inquiries are as follows:
Page 5, 6 and 7: The standard deviation/errors should be presented in the line graph by inserting error bars on every spot in Fig 2, 3 and 4.
Page 7 line 229: The sentence should be complete as: After 56 “days” of culture.
Page 8: It would be better to present the shrimp weight data in a line graph since it is a continuous variable. Based on Table 3, the final weight (day 56) was significantly lowest in the control treatment. The significance could be labelled on the figure 5.
Page 10 line 325: Did the authors quantify or have any evidence to show that the shrimp had really ingested the sea grape? Or it is just because of the light limitation and water turbidity that limit the growth of the sea grape?
Page 10 line 326: It seems that the co-culture would facilitate low growth rates in either the shrimp and the sea grape. What could the findings contribute to the practice of using these macroalgae co-culture in the aquaculture industry, since the results are rather negative in terms of productivity of both cultured organisms.
Page 10 line 336-337: The authors stated “is depend on several key factors”, but they described only one factor “seaweed initial biomass”. This statement is confusing, maybe rephrase the sentence.
Page 10 line 331: A detailed comparison in the growth index of whiteleg shrimp should be provided in this part. For instance, to compare the growth rate obtained in this study with other experiments and regular commercial productions. This would allow the reader to understand the efficiency of sea grape co-culture on the shrimp.
Author Response
All comments for reviewer 2 have been implemented in the attached document.
Author Response File: Author Response.docx
Reviewer 3 Report
The MS is interesting and shows sound information. The experiments were well designed, and the results were clearly described. Some typos are highlighted in the text.
Comments for author File: 
Comments.pdf
Author Response
All comments for reviewer 3 have been implemented in the attached document.
Author Response File: Author Response.docx
Reviewer 4 Report
The authors investigated the effect of an integrated aquaculture-seaweed system (shrimp and sea grape) on water quality, growth, and survival of the whiteleg shrimp. They designed five treatments with four sea grape densities to test their hypothesis regarding the optimum density for this polyculture system. This manuscript (MS) was clearly written and was easy to understand. This work can help the aquaculture sustainability of this shrimp species. However, some major issues significantly compromised the quality of this MS.
Major comments:
- First, the manuscript needs to be edited to improve the language of the MS and fix some errors.
- The main issue that caused me to reject this MS is the fundamental problems in growth data. At the end of the experiment, they sampled 30 shrimp out of 200-300 ones per tank; accordingly, they reported this weight as the final weight of the tank. Therefore, the results of growth are doubtful and questionable. Another issue is that the survival rate of the control group is 54%!! Which is too low and showing some fundamental problems that negatively influenced the shrimps and system. Therefore, growth data from this point is not reliable as well.
However, I have touched on some more points that can contribute to the improvement of this MS.
Abstract
- Line 18, change to (P<0.05)
- Please make the abstract more numeric with the results, at least report the shrimp growth.
Introduction:
- Line 29-31, 4 million is not a big number for aquaculture production; please revise and recheck the stats for aquaculture production.
- Line 32, 82% of what
- Line 33 and elsewhere, for the first time, use common name plus scientific name and rest just use the common name of shrimp or any other species you mention in this MS.
- Line 39, the protein requirement of this shrimp species is not “low”.
- Line 40, how much is intensive? Please mention it.
- Line 61, please mention the novelty of your work here.
- Material and methods
- Line 66, did you mean experimental design?
- Line 69, please explain more about density and bring the reference that this density was high, moderate, or low
- Line 84, what do you mean by 300 ind/m3. I think you meant individuals; if yes, please write it up
- Line 100-101, can you please mention what the photoperiod was? You feed shrimp at 8 PM, was the day still light at that time?
- Line 102, please mention how were pellet size and feeding rate changed with the increase of shrimp size.
- Line 103, how many percentages of water was siphoned?
- Line 135 to 140, I think the results of the final growth of shrimp is just for 30 shrimp per tank and not all of them. The stoking density was 300 individuals, and you just sampled 30 one's per tank, and you reported them as the final weight of each tank. This is not a reliable result for growth data.
Results
- Line 174-176, you can say this if there is a significant difference between the five treatments on day 56.
- Line 189-192, please just compare the results with Duncan among five treatments, and if there was a significant, please report it. For any sentence you mention was higher or lower, please be clear the difference was significant or not.
- For figure 2, please compare the transparency in day 56 between five treatments with Duncan.
- Also, please make sure the quality of the figures is acceptable according to the requirement of the journal.
- For using Duncan, first, make sure the P-value of ANOVA is significant, and then apply it. You can apply Tukey Test, which is one step comparison, and you can rely on the output of the test without checking the P-value of ANOVA.
- Line 204, please mention whether you calculated the whole biomass of sea grape at the end of the experiment or just were sampled like shrimp.
- Line 215-219, please summarize this part and other parts of the results. Please just report important results instead of reporting all details.
- Figure 4, it does not make any impressive point as the density was different from the first. I suggest exchanging this figure with reporting biomass increment or relative growth rate as they are the same-scaled factors between treatments.
- I did not get through the rest of the results and discussion due to fundamental problems in growth data.
Best regards
Author Response
All comments for reviewer 4 have been implemented in the attached document.
Author Response File: Author Response.docx
Round 2
Reviewer 4 Report
The authors improved the quality of this manuscript (MS). However, some more efforts are required to get it close to the final version.
- For using Duncan, first, make sure the P-value of ANOVA is significant, and then apply it. You can apply Tukey Test, which is one step comparison, and you can rely on the output of the test without checking the P-value of ANOVA.
You did not understand what my comment was. For reporting the Duncan results, the P-value of ANOVA is required to be added to the results. Like this paper: https://0-doi-org.brum.beds.ac.uk/10.1111/j.1365-2095.2006.00439.x
Abstract
- Line 18, make sure you have used the complete form of the words in the abstract. In other sections, please make sure you defined the abbreviation for the first time in MS, then use it.
- Line 18 and elsewhere, change to (P<0.05), P italic, and uppercase.
- Material and methods
- Line 107, please mention lipid and energy contents of diet as well.
- Line 151-152, please make sure you have been consistent with starting the formula with uppercase or lowercase.
Results
- Line 202-204 and elsewhere, as I mentioned in the last version as well, please just compare the results with Duncan among five treatments, and if there was a significant, please report it. For any sentence you mention was higher or lower, please be clear the difference was significant or not. Please avoid using “this difference was not observed between the S+1kg and S+1.5kg treatments” and just compare the five treatments and report which one/ ones were significantly higher than others.
- Table 3, why there is no data for Control, please explain in the footnote of Table 3.
- Line 228-231, again, this way of reporting results is not correct. You have Control and should just compare other treatments with the Control. “that for S+1.5kg and S+2kg groups, and the latter two groups showed no statistical differences” you can say this only when compare it with T-Test which is out of scope of this MS. For this case report like this:
Statistical analysis showed that the growth rates of sea grape in S+0.5kg and S+1.5kg were significantly higher than others (P < 0.05) (Table 3). - If there is no significant difference no need to report P-Value; please update the MS from this point.
- Figure 4 is confusing; if you already report the data in Table 3, you can delete this part.
- Line 250-251, according to which table/figure? According to Figure 5, there is no significant difference after 56 days among treatments.
- Please combine Table 4 and Table 5 and also the results section for them.
- Line 271-273, please added this part to the last paragraph; no need to be reported in a separate part.
- Line 296, added to the last paragraph, no need to report in a separate paraph.
Discussion
Very well-prepared section and all required information well presented.
Please make sure you are consistent in the MS with “sea grape” and not used seagrape
Best regards
Author Response
Reviewer 4 suggestions have been implemented in the new version of the manuscript.
Thank you.
Best regards
Author Response File: Author Response.docx
