Housefly Maggot Meal as a Potent Bioresource for Fish Feed to Facilitate Early Gonadal Development in Clarias gariepinus (Burchell,1822)

Round 1

Reviewer 1 Report

General comments:

The authors have performed a 24-week study focusing on the influence of dietary maggot -meal inclusion in Clarias gariepinus catfish on gonad development and growth performance. Although the  study design and results appear to be novel, especially in regard to this species, there are significant flaws in the writing style and content. 

The contents of the manuscript and scientific design do not fit the title of the paper, the title should be changed.  Authors attempted to contextualize the effect of the current global pandemic on development and status of bioeconomy and aquaculture with alternative protein in fish feeds, more specifically maggot-meal as protein source. The connection does exist, however not nearly on the scale that is indicated in the title. The title should be more specific to the aim and contents of ths study. Therefore, introduction should be rewritten and optimized to the content of the manuscript. 

Another general observation is that authors fail to postulate a clear hypothesis in the beginning of the study. This is especially important for a potential influence of maggot-meal on GSI and its significance, i.e. why would there be an influence of test diets on GSI and what is its significance in a physiological context. Too much space has been given to elucidate the current effect of COVID pandemic on global aquaculture and too little space to the significance of method selection and objectives of this study. Language constructions seem unnecessarily complicated at times and there is a clear need for language revision.
Furthermore, authors should avoid use of jargon (orchestrated, grim, to name a few) as this is not adequate language in scientific writing.
In addition, article text is encumbered with long statements in relation to bio-economy and citations that feel 'piled up' without clear connection to the current study. I advise striping sentences of unnecessary words, remember that in scientific context 'less is more'. Try to tighten the overall manuscript linguistically and make it more simple, this will add value to it. 

Comments in text:

Line 72-please remove  et al from this sentence. 

Lines 73-76- this statment needs a supporting reference. 

Line 104- please complement as it is unclear what 'visceral' refers to.

Line 104-Please define 'insect meal'. If specific , write the name of that species, if not use various in the prefix. I advise the former as you also write 'house fly maggot meal' in the same sentence. 

Line 111-please describe the concept of green transition prior to this. 

Lines 118-120 I do not see how the case study on housefly maggot meal will shed light on other alternative sources. Please rephrase. 

Lines 119-120 As this is the actual goal of your study I find that connecting it to the global issues of pandemic and blue bio-economy in a way that has been attempted in this manuscript is pretentious. The introduction needs to be rewritten. 

Lines 134-136 why is the gonad maturation important? this needs further explanation. How does feed affect the development, please elaborate. What is the significance of egg diameter, this needs further clarification. 

Lines 154-155 are these fish selected strains or wild caught fish that is kept in the pond? This information needs to be added. 

Lines 155-156 where the fish fed during acclimation? If yes, please give the reference to the feed. 7 days acclimation from pond to experimental tanks seems a bit short. 

Line 165 please correct to 'on dry matter basis'. 

Lines 170-172 Please describe the equipment used for mixing and pelletizing. 

Line 174-Table 1 The proximate composition of the individual ingredients and the test ingredient and their origin (fishmeal) is not given anywhere in the manuscript. This information is essential, please include it. 

Line 182 water flow through the tanks, please describe if the water was recirculated or flow through and the water source.

Lines 183-184 where the fish fed a total of 5% of bw per day? Or was it fed 5% of the bw with every feeding? Please clarify. 

Line 186 please indicate frequency of water quality monitoring (daily, weekly?).

Lines 190-191 does this mean that 2 fish were sampled every week from week 12 onwards as well? This would mean that a total of 48 out of 50 fish were sampled before the end? Please clarify this. 

Line 195 please indicate microtome model used.

Lines 203-204- I assume the Kjeldahl method was used for cp? PLease give exact information about the model of the equipment.

Line 238- Table 2 it is surprising that there were no statistical differences between treatments in terms of growth. It is evident that the standard error values are high for some of the test diets and that this may be the main underlaying reason for the lack of significance. However, this may also indicate mistakes in the maintenance protocol and improper housing conditions, leading to large size variation, possibly due to aggression within tanks or perhaps certain metabolic disturbances. Why was this not addressed in preparation and during the experiment? It should also be elaborated on in the result section.

In table 2 superscripts for final weight differ (a and ab) but do not show any significant differences and they do not make sense. Please remove all superscripts as they do not contribute in any way.  

Line 254- table 3 - please remove all superscipts from the table.

In table 3 in some instances the difference in GSi between treatments for certain time points is higher than 100% (ex WK20 D1 vsD4) yet there are no statistical differences, how do you explain this?

Lines 331-333 to claim that there was a difference and positive effect without having the support of statistical analysis is unacceptable. Please rephrase or remove. 

Lines 337-339 again, you make a claim that is not supported by your findings or statistical analysis but is rather based on numerical values, this is unacceptable, please remove or rephrase. 

Line 337 please rearange the references in brackets in right order.

Reference under number 52 does not contain supportive information relevant to your statement. Please remove.

Lines 340-343 It can be seen as somewhat sens-less to discuss the nutrient composition without conducting the nutrient analysis of your test material, in this case the maggot meal. Please provide information- a table with the nutrient content of test ingredients. 

Lines 368-369 how is this statement different than the one on lines 361-362? Why are different references used? Please revise. 

Lines 373-378 this paragraph needs revising. It is difficult to understand what the authors are implying here. 

Lines 379-383 This explanation is not clear enough. What qualifies the maggot meal to possess 'good nutrient composition'? What is 'good' representing? Please clarify! Also, please clarify what is considered as good broodstock quality. The proximate composition of dietary ingredients should be included in this study. This is a conclusive paragraph and should be moved to the end of next paragraph as the authors discuss the same results.

Lines 404-406 include references to where this has been reported previously. 

Lines 416-418 Please contextualize how this is a positive development, as early sexual maturation in aquaculture is most often considered as undesirable trait. 

Lines 418-419 how is this a confirmation of good nutritive value? This statement is unfounded. PLease remove.

Lines 420-421 I disagree, the authors have not had any statistical significance in the growth response and therefore it is unreasonable to draw such conclusions from your results. This is speculation!

Lines 425-427 This is a very far fetched and inproperly supported conclusion, at least in the context of this study. Please remove. 

 

Author Response

Reviewer 1
	Manuscript was edited by an expert from Bradford UK. She undertook proof reading and correcting grammar cum language logic.
The contents of the manuscript and scientific design do not fit the title of the paper, the title should be changed. The title should be more specific to the aim and contents of this study. Therefore, introduction should be rewritten and optimized to the content of the manuscript.	The title is modified and the introduction rewritten/optimized as suggested by the reviewer. See the revised manuscript. thanks
Too much space has been given to elucidate the current effect of COVID pandemic on global aquaculture and too little space to the significance of method selection and objectives of this study. Language constructions seem unnecessarily complicated at times and there is a clear need for language revision.	The manuscript is upgraded and significantly improved as all issues have been addressed including language constructions. thanks
Furthermore, authors should avoid use of jargon (orchestrated, grim, to name a few) as this is not adequate language in scientific writing.	This has been addressed in the revised manuscript. thanks
Line 72-please remove  et al from this sentence	-        et al. has been removed
Lines 73-76- this statment needs a supporting reference.	-        Statement has been removed in the process of general paper revision
Line 104- please complement as it is unclear what 'visceral' refers to.	-        Visceral has been changed. See line 111
Line 104-Please define 'insect meal'. If specific , write the name of that species, if not use various in the prefix. I advise the former as you also write 'house fly maggot meal' in the same sentence.	-        Insect meal has been explained and made clearer -        See line 111.
Line 111-please describe the concept of green transition prior to this.	-        green transition has been explained
Lines 118-120 I do not see how the case study on housefly maggot meal will shed light on other alternative sources. Please rephrase.	-        sentence has been rephrased. -        See line 120
Lines 119-120 As this is the actual goal of your study I find that connecting it to the global issues of pandemic and blue bio-economy in a way that has been attempted in this manuscript is pretentious. The introduction needs to be rewritten.	-        The introduction has been revised
Lines 134-136 why is the gonad maturation important? this needs further explanation. How does feed affect the development, please elaborate. What is the significance of egg diameter, this needs further clarification?	-        The introduction has been revised -        Significance of egg size has been indicated. -        See lines 193-199.
Lines 154-155 are these fish selected strains or wild caught fish that is kept in the pond? This information needs to be added.	-        Clarification has been made  -        See 258
Lines 155-156 where the fish fed during acclimation? If yes, please give the reference to the feed. 7 days acclimation from pond to experimental tanks seems a bit short.	-        This has been done. See line 258-260.
Line 165 please correct to 'on dry matter basis'.	-        This has been done. See line 358
Lines 170-172 Please describe the equipment used for mixing and pelletizing.	-        See line 364.
Line 174-Table 1 The proximate composition of the individual ingredients and the test ingredient and their origin (fishmeal) is not given anywhere in the manuscript. This information is essential, please include it.	-        This has been done. See table 1, line 366.
Line 182 water flow through the tanks, please describe if the water was recirculated or flow through and the water source.	-        The fish were cultured in a semi-static environment.See line 258.
Lines 183-184 where the fish fed a total of 5% of bw per day? Or was it fed 5% of the bw with every feeding? Please clarify.	-        Clarification has been made -        See line 499.
Line 186 please indicate frequency of water quality monitoring (daily, weekly?).	-        Correction has been effected -        See line 502.
Lines 190-191 does this mean that 2 fish were sampled every week from week 12 onwards as well? This would mean that a total of 48 out of 50 fish were sampled before the end? Please clarify this.	Rebuttal: Sampling started from beginning of experiment till the 24th Week.  As such sampling took place only 12 times. A total of 24 fish were sampled per tank.
Line 195 please indicate microtome model used.	-        The model has been indicated. See line 511.
Lines 203-204- I assume the Kjeldahl method was used for cp? PLease give exact information about the model of the equipment.	-        The model has been indicated -        See line 518.
Line 238- Table 2 it is surprising that there were no statistical differences between treatments in terms of growth. It is evident that the standard error values are high for some of the test diets and that this may be the main underlaying reason for the lack of significance. However, this may also indicate mistakes in the maintenance protocol and improper housing conditions, leading to large size variation, possibly due to aggression within tanks or perhaps certain metabolic disturbances. Why was this not addressed in preparation and during the experiment? It should also be elaborated on in the result section.	Thanks for this observation. The experimental protocol was not faulty rather the sample size may have probably affected the standard error values.
In table 2 superscripts for final weight differ (a and ab) but do not show any significant differences and they do not make sense. Please remove all superscripts as they do not contribute in any way.	-        all superscripts have been removed. See revised manuscript.
Line 254- table 3 - please remove all superscripts from the table.	-        all superscripts have been removed -        see revised manuscript
In table 3 in some instances the difference in GSi between treatments for certain time points is higher than 100% (ex WK20 D1 vsD4) yet there are no statistical differences, how do you explain this?	-        The significance of difference between means were determined by Duncan’s multiple range test. However, all superscripts have been removed as recommended as there was no significance difference detected.
Lines 331-333 to claim that there was a difference and positive effect without having the support of statistical analysis is unacceptable. Please rephrase or remove.	-        Sentence is rephrased -        See line 886-887.
Lines 337-339 again, you make a claim that is not supported by your findings or statistical analysis but is rather based on numerical values, this is unacceptable, please remove or rephrase.	-        Sentence is removed.
Line 337 please rearrange the references in brackets in right order.	-        This has been done. See line 932.
Reference under number 52 does not contain supportive information relevant to your statement. Please remove.	Reference 52 is removed!! Thanks
Lines 340-343 It can be seen as somewhat sens-less to discuss the nutrient composition without conducting the nutrient analysis of your test material, in this case the maggot meal. Please provide information- a table with the nutrient content of test ingredients.	Nutrient composition (proximate analysis) has been added (Table 1)
Lines 368-369 how is this statement different than the one on lines 361-362? Why are different references used? Please revise.	The sequence of oocyte stages is as follows: stage I—primary growth; stage II—cortical alveoli growth period; stage III—early vitellogenic oocytes; stage IV—late vitellogenic phase; and stage V—mature/ovulated oocyte, full of yolk (with lipid and protein globules).   Ovulation comes with the last stage of oocyte development which did not appear as at the time (24th week), may be because of time, or require more time.
Lines 373-378 this paragraph needs revising. It is difficult to understand what the authors are implying here.	-        The paragraph has been revised to make it clearer. See line 964-966.
Lines 379-383 This explanation is not clear enough. What qualifies the maggot meal to possess 'good nutrient composition'? What is 'good' representing? Please clarify! Also, please clarify what is considered as good broodstock quality. The proximate composition of dietary ingredients should be included in this study. This is a conclusive paragraph and should be moved to the end of next paragraph as the authors discuss the same results.	-        The sentences have been recast to make them clearer -        proximate composition of diet ingredients have been included. -        See line 970.
Lines 404-406 include references to where this has been reported previously.	-  The reference has been included, see line 1089. -
Lines 416-418 Please contextualize how this is a positive development, as early sexual maturation in aquaculture is most often considered as undesirable trait.	-        African Catfish does not have a problem of untimely maturation. African catfish mature at the age one year to two years. Earlier maturation in this case will enhance food production.
Lines 418-419 how is this a confirmation of good nutritive value? This statement is unfounded. PLease remove.	-        Statement has been removed -
Lines 420-421 I disagree, the authors have not had any statistical significance in the growth response and therefore it is unreasonable to draw such conclusions from your results. This is speculation!	-        - Statements and line of thought have been modified in line with study results
Lines 425-427 This is a very far fetched and inproperly supported conclusion, at least in the context of this study. Please remove.	-        The far fetched conclusions have been removed

Author Response File: Author Response.pdf

Reviewer 2 Report

The present work assesses the effect of maggot meal, as substitute for fish meal, on gonadal development in the African catfish. This is an veru interesting approach since the need for alternative ingredients to fish meal and oil is one milestone in aquaculture research. Overall, the study is well designed, however some issues need to be addressed:

- The manuscript needs a global revision of english. Some citations in the text nedd to be well formatted (e.g. line 72).

- The introduction is too long and part is out of the scope of the work. Until line 90 the topic of alternative ingredients (the main topic of the study) is not addressed, so in such long introduction the backgroud and objective of the study became vague. Reviewer suggests to rewrite and fit the introduction to the specific scope of the work. The objective (lines 118-121) should be moved to the end of the introduction.

- Line 137: the mode of spawning is not an environmental factor, it is innate for each species. In material and methods substitute tank's dimensions for water volume.

- In material and methods subtitute tank's dimensions by volume.

- Line 183: substitute two regimes per day by two meals per day.

- Line 227: Table 1 is already shown in materials and methods sections, it should not be part of the results. 

- Line 234: since no statistical differences were obtained, authors should not indicate "increase body biomass", rewrite to "showed a trend to higher body biomass".

- Overall in the results section, if no differences were obtained between treatments letters as statistical indicators should be deleted from the tables.

- Do authors know which bioactive compounds from maggot meal may promote gonad development?

Author Response

Reviewer 2	-
	-        Manuscript was edited by an expert from Bradford UK. She undertook proof reading and correcting grammar cum language logic.
The present work assesses the effect of maggot meal, as substitute for fish meal, on gonadal development in the African catfish. This is a very interesting approach since the need for alternative ingredients to fish meal and oil is one milestone in aquaculture research. Overall, the study is well designed, however some issues need to be addressed:	-        We are thankful the reviewer.
- The manuscript needs a global revision of english. Some citations in the text nedd to be well formatted (e.g. line 72).	-  This line has been removed in the course of reviewing the introduction -
The introduction is too long and part is out of the scope of the work. Until line 90 the topic of alternative ingredients (the main topic of the study) is not addressed, so in such long introduction the backgroud and objective of the study became vague. Reviewer suggests to rewrite and fit the introduction to the specific scope of the work. The objective (lines 118-121) should be moved to the end of the introduction.	- This has been done. See the revised manuscript.
- Line 137: the mode of spawning is not an environmental factor, it is innate for each species. In material and methods substitute tank's dimensions for water volume.	- This has been done. See line 220.
- Line 183: substitute two regimes per day by two meals per day.	-  This has been done. See line 510.
- Line 227: Table 1 is already shown in materials and methods sections, it should not be part of the results.	-  This has been done. Thanks.
Line 234: since no statistical differences were obtained, authors should not indicate "increase body biomass", rewrite to "showed a trend to higher body biomass".	-  This has been done. See line 618.
- Overall in the results section, if no differences were obtained between treatments letters as statistical indicators should be deleted from the tables.	-  This has been done
- Do authors know which bioactive compounds from maggot meal may promote gonad development?	-  This was assessed. Thanks.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The manuscript has been improved after the first round of revision. The title is also more adequate for the scientific study. The authors have thereby addressed most, but not all of the comments and suggestions adequately. Please see the list of comments and suggestions further down in the text. The authors indicate that the manuscript has been proofread by a language expert but this is not clear in the text. This aspect must be improved before the manuscript can be accepted for publication. 

 

Furthermore, here are the comments to the revised manuscript. 

General comments:

Authors use a term 'magmeal' in the title and throughout the manuscript. Magmeal seems to be a trademarked name belonging to a private company (Agriprotein) and it is therefore considered intellectual property. Since the maggot meal used in this study is not a product of that company I advise to refrain from using this term and use the full name - maggot meal. 

Authors need to address the overall language and phrasing in the manuscript. Currently it is not fit for a scientific publication. Language constructions are unpolished and sometimes difficult to understand. Selection of adverbs is robust and also not suited for scientific publication in an international journal. Synonyms are used throughout the manuscript, this is not optimal, please try to be consistent in the use of terms when addressing identical issues, concepts etc. Some sentences are flawed due to inadequate phrasing, where it is difficult to find the meaning and understand the message authors want to convene.  Punctuation is often incorrect or missing. A second linguistic revision must be performed to bring the language in the manuscript to the standard worthy of scientific publication.

Comments in text:

Line 60: what is a fish sector? Please use ‘fisheries’ instead.

Line 62: please rephrase (also elsewhere were it may apply in the manuscript): 'cheap protein supply' into 'affordable protein supply'!

Lines 100-101: According to which source? Please provide reference for the statement (More emphasis and energy are now expended on alternative protein sources rather than the conventional protein source.)!

 

Line 118 ( and elsewhere in the manuscript)  Avoid starting a sentence with 'It'. If possible, start the sentence with the noun instead.

Lines 178-179: The clarification is not sufficient, please provide adequate information in regard to whether the fish is of wild type or has previously been selected through a breeding programme.

Lines 179-180 Semi static concrete tanks- please clarify what does semi-static mean? I have never heard of this term.

Lines 177-186 authors did not provide requested information about the water source, where does the water in the experimental tanks come from? (well water, pond water, recirculation, something else?)

Result section

In the first manuscript version, I commented on the results displayed in table 2 (now table 3) in regard to lack of significance. The original comment and reply from authors is as follows:

Line 238- Table 2 it is surprising that there were no statistical differences between treatments in terms of growth. It is evident that the standard error values are high for some of the test diets and that this may be the main underlying reason for the lack of significance. However, this may also indicate mistakes in the maintenance protocol and improper housing conditions, leading to large size variation, possibly due to aggression within tanks or perhaps certain metabolic disturbances. Why was this not addressed in preparation and during the experiment? It should also be elaborated on in the result section.

Thanks for this observation. The experimental protocol was not faulty rather the sample size may have probably affected the standard error values.

The answer provided by the authors is not sufficient! The authors need to elaborate on the lack of significant differences in the manuscript! It is strange to see such high numerical and yet no statistically significant differences. It is not enough to say that it was ‘probably’ affected by the sample size, what does that mean? Please provide the input (the way it was entered into SPSS) and output files from the statistical software clearly indicating visible raw data used for final weight, mean weight gain and SGR.   

 

Lines 256-257: If, as the authors indicate, there is a 'trend' towards higher body mass, the P values need to be provided that would support such a statement. Otherwise, this is just a numerical difference. The term 'trend' is subjective and somewhat biased  identification of own results, without support in statistics. Even so, the term is often used in scientific literature to illustrate an ‘almost’ significant difference. One could argue that the statistical difference is ‘almost’ significant if the P value is no higher than 0.06. Therefore, in this case, p-value of under 0.06 needs to be existing to illustrate  a 'trend'.

Lines 260- 265 In table 3 footnote please indicate the sample size for each parameter (n).

Lines 348-349 please delete this sentence, redundant. The following sentence is basically a repetition of that statement.

Line 397: the authors did not elaborate sufficiently on what is meant by 'good nutrient composition'- furthermore writing that something is 'good' or 'bad' in a scientific context is unacceptable. A more suitable term would be 'suitable' or 'of high quality'. Please change adequately throughout the manuscript.

Line 431 and onward: Instead of ‘apparently’, please use the adequate term; ‘numerically’!

Author Response

General comments:

Authors use a term 'magmeal' in the title and throughout the manuscript. Magmeal seems to be a trademarked name belonging to a private company (Agriprotein) and it is therefore considered intellectual property. Since the maggot meal used in this study is not a product of that company I advise to refrain from using this term and use the full name - maggot meal. 

 

Done – Corrected! -  Magmeal has been changed to maggot meal. 

 

 

Authors need to address the overall language and phrasing in the manuscript. Currently it is not fit for a scientific publication. Language constructions are unpolished and sometimes difficult to understand. Selection of adverbs is robust and also not suited for scientific publication in an international journal. Synonyms are used throughout the manuscript, this is not optimal, please try to be consistent in the use of terms when addressing identical issues, concepts etc. Some sentences are flawed due to inadequate phrasing, where it is difficult to find the meaning and understand the message authors want to convene.  Punctuation is often incorrect or missing. A second linguistic revision must be performed to bring the language in the manuscript to the standard worthy of scientific publication.

 

A second round of language review and editing was undertaken to bring the manuscript to standard

 

Comments in text:

Line 60: what is a fish sector? Please use ‘fisheries’ instead.

Done – Corrected!

Line 62: please rephrase (also elsewhere were it may apply in the manuscript): 'cheap protein supply' into 'affordable protein supply'!

Done – Corrected! - affordable protein supply has been used in place of cheap Protein supply

Lines 100-101: According to which source? Please provide reference for the statement (More emphasis and energy are now expended on alternative protein sources rather than the conventional protein source.)!

 Done – Corrected! - Sentence has been recast and reference supplied

Line 118 ( and elsewhere in the manuscript)  Avoid starting a sentence with 'It'. If possible, start the sentence with the noun instead.

 Done – Corrected!

Lines 178-179: The clarification is not sufficient, please provide adequate information in regard to whether the fish is of wild type or has previously been selected through a breeding programme.

Done – Corrected!

Lines 179-180 Semi static concrete tanks- please clarify what does semi-static mean? I have never heard of this term.

Done – Corrected! – the sentences have been re-cast.

 

Lines 177-186 authors did not provide requested information about the water source, where does the water in the experimental tanks come from? (well water, pond water, recirculation, something else?)

Done – Corrected! Information has been supplied

 

Result section

In the first manuscript version, I commented on the results displayed in table 2 (now table 3) in regard to lack of significance.

 

The original comment and reply from authors is as follows:

Line 238- Table 2 it is surprising that there were no statistical differences between treatments in terms of growth. It is evident that the standard error values are high for some of the test diets and that this may be the main underlying reason for the lack of significance. However, this may also indicate mistakes in the maintenance protocol and improper housing conditions, leading to large size variation, possibly due to aggression within tanks or perhaps certain metabolic disturbances. Why was this not addressed in preparation and during the experiment? It should also be elaborated on in the result section.

Thanks for this observation. The experimental protocol was not faulty rather the sample size may have probably affected the standard error values.

The answer provided by the authors is not sufficient! The authors need to elaborate on the lack of significant differences in the manuscript! It is strange to see such high numerical and yet no statistically significant differences. It is not enough to say that it was ‘probably’ affected by the sample size, what does that mean? Please provide the input (the way it was entered into SPSS) and output files from the statistical software clearly indicating visible raw data used for final weight, mean weight gain and SGR.   

Information!

Reviewer’s argument is correct regarding the high Standarded error and the consequent lack of segnificance for final weight, mean weight gain and SGR. The high standarded error was observed on treatment 2 and 4 (which recorded an unusal high growth in one of the three replicates).  

All replicate treatment however, received same attention. 

 

The lack of significance may be due to high standard error occasioned by an unusal high fish growth recorded in one of the three replicates of treatment D2 and D4

 

Raw data for initial and final fish sampling are presented

	Initial status
Tank	Diet		No of fish		Total wt of fish (g)	Average weight of fish (g)
T1R1	D1		50		80.09	1.6
T1R2	D1		50		85.37	1.71
T1R3	D1		50		82.73	1.66
T2R1	D2		50		84.75	1.7
T2R2	D2		50		83.74	1.67
T2R3	D2		50		84.25	1.69
T3R1	D3		50		86.77	1.74
T3R2	D3		50		74.77	1.5
T3R3	D3		50		80.77	1.62
T4R1	D4		50		80.60	1.61
T4R2	D4		50		79.73	1.6
T4R3	D4		50		80.17	1.61
Week 24
Tank	Diet	No of fish		Total wt of fish (g)		Average weight of fish (g)
T1R1	D1	22		1730.24		78.92
T1R2	D1	22		1400		63.64
T1R3	D1	22		1565.12		71.14
T2R1	D2	22		2566.67		116.67
T2R2	D2	24		1569.23		65.38
T2R3	D2	23		2067.95		89.91
T3R1	D3	24		2045.96		85.29
T3R2	D3	23		2029.41		88.24
T3R3	D3	23		2037.69		88.6
T4R1	D4	24		1600.08		66.67
T4R2	D4	25		2840.01		113.64
T4R3	D4	24		2220.05		92.5

 

SPSS INPUT DATA

DietTreatment	InitialWeight	FinalWeight	Weightgain	SGR
1.0	1.6	78.92	77.32000000000001	2.1657950288381547
1.0	1.71	63.64	61.93	2.0093049071972318
1.0	1.66	71.14	69.48	2.0876845356399207
2.0	1.7	116.67	114.97	2.3492895476519977
2.0	1.67	65.38	63.709999999999994	2.0374404304818894
2.0	1.69	89.91	88.22	2.207822578367611
3.0	1.74	85.29	83.55000000000001	2.1623178339469895
3.0	1.5	88.24	86.74	2.2636640371317127
3.0	1.62	88.6	86.97999999999999	2.2231698379815237
4.0	1.61	66.67	65.06	2.068622720907554
4.0	1.6	113.64	112.04	2.3683510709668063
4.0	1.61	92.5	90.89	2.2505413697344494

 

Lines 256-257: If, as the authors indicate, there is a 'trend' towards higher body mass, the P values need to be provided that would support such a statement. Otherwise, this is just a numerical difference. The term 'trend' is subjective and somewhat biased  identification of own results, without support in statistics. Even so, the term is often used in scientific literature to illustrate an ‘almost’ significant difference. One could argue that the statistical difference is ‘almost’ significant if the P value is no higher than 0.06. Therefore, in this case, p-value of under 0.06 needs to be existing to illustrate  a 'trend'.

ANOVA
		Sum of Squares	df	Mean Square	F	Sig.
Mean Initial weight	Between Groups	.012	3	.004	.891	.486
	Within Groups	.035	8	.004
	Total	.047	11
Mean Final weight	Between Groups	787.092	3	262.364	.824	.516
	Within Groups	2546.266	8	318.283
	Total	3333.357	11
Weight gain	Between Groups	788.373	3	262.791	.825	.516
	Within Groups	2547.614	8	318.452
	Total	3335.986	11
SGR	Between Groups	.038	3	.013	.900	.482
	Within Groups	.112	8	.014
	Total	.150	11

Lines 260- 265 In table 3 footnote please indicate the sample size for each parameter (n).

Done – Information is added – Initial number of fish per tank = 50; Final number of Fish per tank = 22 – 25 (2 fish were sampled each week for Gonad assesment till Week 24)

 

Lines 348-349 please delete this sentence, redundant. The following sentence is basically a repetition of that statement.

Done – Corrected! – Sentence has been deleted

Line 397: the authors did not elaborate sufficiently on what is meant by 'good nutrient composition'- furthermore writing that something is 'good' or 'bad' in a scientific context is unacceptable. A more suitable term would be 'suitable' or 'of high quality'. Please change adequately throughout the manuscript.

Done – Corrected! – “Suitable” and quality have been used to replace “good”

Line 431 and onward: Instead of ‘apparently’, please use the adequate term; ‘numerically’!

Done – Corrected! - apparently’ has been changed to ‘numerically’

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.