Stock Status of Two Commercially Important Catfishes, Mystus gulio (Hamilton 1822) and Mystus cavasius (Hamilton 1822), in Relation to Environmental Variables Along the Lower Stretches of the River Ganga, India

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Review comments on manuscript by Kumar das et al.

 Stock status of two commercially important catfishes, Mystus gulio (Hamilton 1822), and Mystus cavasius (Hamilton 1822) in relation to environmental variables along the lower stretches of the river Ganga, India

The aim of the paper was to describe the stock status of two commercially important fish species in relation to environmental variables along the river Ganga.  For the two species, the authors calculated  a variety of growth and mortality parameter to assess their stock status.  The also assessed a range of environmental parameters at the sites where fish were sampled. The results of the study showed that both species are currently being overexploited.  They then make recommendations of future management measures for the fisheries for these two species along the river Ganga.

The manuscript is well written and has no major grammatical issues. The data presented in the paper achieve the study aims and provides an original contribution to detailing the status of the fisheries for the two species in the river. The statistical analysis and figures showing the results in the manuscript are clear and relevant to presenting the results of the study.  As such, I consider that the current manuscript is suitable for publication.

Specific comments on the manuscript are detailed below:

Lines 20 – change spelling of fishing to fisheries

Line 59 – change ‘that comes under’ to ‘in’

Line 65 – remove space before comma (Hamilton, 1822) ,

Line 78 – What does delicacies mean?

Lines 124–125 – change ‘using bag net to ‘using a bag net’.

Lines 125–126 – change ‘from gill net using bag net to ‘from a gill net’.

Line 126 – change ‘set barrier net to ‘a set barrier net’.

Lines 178 – change ‘the Ganga river’ to ‘the river Ganga’.

Line 184 – delete ‘such as’.

Line 187 – change ‘the growth equation of Von BettaLife has been demonstrated as’  to ‘the Von Bertalanffy growth equation has been calculated as’.

Line 195 – Delete ‘Similarly,’.

Lines 195–203 – These lines have a different font size compared with the rest of the text.

Line 197 – change ‘were also obtained’ to  ‘were calculated’.

Line 199 – delete ‘were recorded’.

Lines 205, 222, 2,55, 281, 319, 331, 334, caption of Table 4 and line 3 in the conclusions section – change ‘of river Ganga’ to ‘of the river Ganga’.

Line 226 – delete ‘by’.

Line 231– delete ‘But’.

Line 237 – change ‘of M. gulio stock’ to ‘of the M. gulio stock’.

Line 240 – change ‘obtained’ to ‘calculated’.

Line 242 – change ‘from Bhadra’ to ‘from the Bhadra’.

Line 245 – change  ‘indicating overexploited’ to  ‘indicating an overexploited’.

Line 251 – change ‘indicates lower’ to ‘indicates a lower’.

Line 263 – change ‘was noticed’ to ‘occurred’.

Line 267– change ‘a breeding season.’ to  ‘the year’.

Line 270 – delete ‘at its highest season’.

Lines 273–274 – change ‘in Hemavathi reservoir’ to  ‘in the Hemavathi reservoir’.

Lines 276  delete ‘, which justifies the present study.’

Lines 290–292 – What does this sentence mean.  The authors should revise the text to clarify the meaning.

‘This, indicates growth overfishing just started for this species along the stretches of the river Ganga as the majority of fish were being caught before their maturation and spawning.’

Table 2 – change ‘Peakspawning’ to ‘Peak spawning’.

Line 300 – delete ‘While’.

Lines 303 – change ‘number of fish populations’ to ‘abundances’.

Line 304 – change ‘population’ to ‘abundances’.

Line 309 – change 'the lower.’ to ‘the lower river Ganga’.

Lines 315 and 315 – change ‘population’ to ‘abundances’.

Line 283 – change ‘population of fish’  to ‘ of the fish population’.

Line 354 – change ‘depth’ to ‘depths’.

Line 361 – delete ‘, it is a crucial indicator of water quality.’

Line 367 – delete ' than other sampling sites’.

Line 375 – change ‘is saline and’ to ‘is a saline and’.

Lines 378–379  – change ‘ estuarine zone as the tide and the  influx of salt water from the sea have’ to ‘estuarine zone as the influx of salt water from the sea has’.

Line 381–382 – change ’zone ideal for the growth and habitat of M. gulio.’ to  ‘zone are ideal for the growth of M. gulio.’

There are several issues with the references. The authors should review and revise the references in the paper to make them consistent with the journal guidelines.

For numerous references, the first letter of each word in the paper title is capitalised. These should be revised to sentence case. These are No 22, 23 and 67.

Line 54 – is the spelling of Projekt correct?

Line 66 – change ‘fish’ to ‘Fish’.

 

Line 128 – change ‘gangaticMystus:’ to ‘gangaticMystus:’.

References 28, 30 and 54 – Abbreviate the journal name.

Lines 70, 80 and 144 – the scientific name should be italicised.

Line 111 – Fishbyte vs line 112 Fish Byte.  Be consistent with spelling.

References 35 and 36 – remove the italics from the paper title.

Reference 51 – include the journal details and page numbers.

References 53 and 54 - italicise the journal title.

Line 153  – delete second comma  ‘J. Inland Fish. Soc. India, ,’.

Line 165 – change ‘boies’ to ‘bodies’.

 

 

 

 

 

Author Response

Thanks to the respective reviewers for the constructive comments and make the manuscript more presentable format. The manuscript has been revised as per the suggestions of the reviewers, and necessary corrections/editions are marked with yellow color in the MS master file for ready reference, please.
Point-wise clarifications are hereby attached in PDF format with questions and answers mode.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Though the research design and the methods are adequately described, I found many flaws in the manuscript, mainly in the presentation of results, that needs to be addressed. 

Specific comments.

Lines 44-46: The text is confusing. Consider rephrasing as follows: The length at first capture of M. cavasious exceeds the length at maturity, exhibiting that the juveniles are captured more often, and the current level of exploitation (E) of M. cavasius is just over the optimal level of exploitation...".

Line 47: "..., therefore the stock is at risk of being ideally exploited.".  What the authors mean ? How can the stock be "at risk" of being "ideally exploited". I do not see any "risk" here.

Line 121: Figure 1 is confusing. It could be improved by showing the Arabic Sea and the Indian Ocean in the general map, and Bangladesh territory as well. In the enlarged map of sampling sites, show coastline at West and East of the Ganga river estuarine zone.

Line 152: "...where "T" represents the average annual water temperature. Please report the source data (reference, if any) for this information.

Line 187: Consider replacing "demonstrated" with "estimated".

Line 189: "..as 58, 87, 109, 126, and 139 mm...". All the reported values are wrong. Verify and change with the corrected ones (they should be: 68, 98, 121, 138, 150).

Line 190:  "The estimated smallest length was 124 mm with a corresponding age of 0.98 years.". Please clarify. Based on the reported Von Bertalanffy parameters, the length corresponding to 0.98 years is  66.92 cm. Consider removing.

Line 193: Consider replacing "...at 4.017" with "as 4.017".

Lines 200-201: based on the reported Von Bertalanffy parameters, the correct (rounded) length values corresponding to ages 1, 2, 3, 4 and 5 years are 54, 87, 115, 137, and 156 cm.  

Line 244: "....which justifies the present study." What do the authors exactly mean here? Maybe that results of Thippeswamy et al. [45] are "in agreement with the results of the present study"? Please clarify and/or revise accordingly.

Line 248. Replace "indirect" with "inverse". 

Lines 250-252. Unclear, try rephrasing. What about "Accordingly, for M. gulio the estimated relatively small asymptotic length indicates a longer life span, while the estimated low growth coefficient implies a lower natural mortality."?

Lines 258-260: "..., with a single peak from May to July (Figure 5a)." Figure 5a is unclear. It does not seem to show a length frequency distribution. How the "recruitment curves" were estimated? The vertical axis show abundance of recruits (by month, horizontal axis)? If yes, how recruits are defined? Clarify in the text and in the figure caption, and amend the figure itself accordingly (starting with the units of the vertical axis , which are missing).

Lines 285-288. Rephrase. Suggestion: "The length at maturity of M. gulio from Indian waters was reported as 83 mm for males and 85 mm for females by Lal et al. [47], and 62 mm by Pantulu [53]. The L_c recorded in the present study is far above the above cited values, indicating a sustainable exploitation.".

Lines 344-345: "Balagarh shows the highest and the lowest range of water temperature (18.7-33.9 0C)...". Do the authors mean "the minimum and the maximum temperature, and the highest temperature range"? Revise accordingly.

Lines 366-367: "the maxium deviation o TDS ...". Clarify. What do the authors mean with TDS value deviation? Deviation related to what? Try rephasing.

Lines 368-369: Move "(DO>5)" at the end of the sentence, before citations [57,26]. 

Lines 376-377: "..., which makes them ideal homes for M. cavasius." Please provide a reference, if any, or rephrase if a reference is not available.

Lines 381-382: "...indicating the saline and transition zone ideal for the growth and habitat of M. gulio.". Please provide a reference, if any, or rephrase if a reference is not available.

Conclusions, lines 7-8. "In light of the impending overexploitation of the species at an ideal fish size, ....". "impending"? or "impeding" instead? text "at an ideal fish size" is apparently misleading here and in both cases it should be removed . Rephrase.

Conclusions, lines 11-12. "...and the length at first capture is higher than the length at maturity, indicating the juveniles are caught more." Actually, the estimated length at first capture of M. cavasius (89.42 cm, line 285 and line 290) is LOWER than length at maturity estimated by Bhatt [49] (100 mm, line 289). If the reported L_c and L_m values for M. cavasius are correct,  please amend the text accordingly.

 

Comments on the Quality of English Language

The quality of English needs to be improved. Some sentences are hard to understand. The authors are asked to use a proofreading service to revise their manuscript before resubmission.   

Author Response

Thanks to the respective reviewers for the constructive comments and making the manuscript more presentable format. The manuscript has been revised as per the suggestions of the reviewers, and necessary corrections/editions are marked with yellow color in the MS master file for ready reference, please.
Ponit-wise clarifications are hereby attached in PDF format with questions and answers mode.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

General comments.

It seems to me the authors were in a hurry with the amendments in the text that I suggested in my first review.

Actually, first of all I strongly recommend using a proofreading service in order to improve the English quality, as the text is often unclear. I tried to fix some issues again, but I am still not satisfied about the general level of the English. Please try to address this issue before resubmitting.  

Specific comments.

Line 153: ("India Meteorological Department)". Provide a reference here and add it in the list of references. It can be a paper, a report or a link to a data repository.

Line 191: I checked again the calculation by using an excel sheet as well. Provided that you used the population parameters reported in Table 1 (i.e.: L∞ =183.23, K=0.31 and to=-0.486), the lengths (in mm) corresponding to ages 1, 2, 3, 4 and 5 are 68, 98, 121, 138, 150. Please, check again your formula in the excel sheet, or provide your sheet, evidencing the parameters you used.
Figure 3a needs to be changed accordingly, as it reflects the reported (wrong) values instead.

Lines 252-256: Actually, L∞ of M. gulio is lower than L∞ of M. cavasius (183.23 vs. 246.23), and at the same time K of M. gulio is higher than the K value of M. cavasius (0.31 vs. 0.19), and tmax of M. gulio in higher than tmax of M. Cavasius (9.19 vs. 15.49) . So, according to the Beverton and Holt [46] direct relationship with K and inverse relationship with both lifespan and asymptotic length, natural mortality should be higher for M. gulio. And actually this is the case, considering that the natural mortality estimated by lenght-converted catch curve is M=0.49 for M. gulio, whereas for M. cavasius is M=0.33. Consequently, amend as follows: "Therefore the present study, in estimating a greater growth coefficient (K), a lower asymptotic length (Linf) and a shorter lifespan
(tmax), indicates a higher natural mortality in M. gulio.", or something similar.

Conclusions, line 8: Of the two, one. Either "impeding overexploitation of the species", or  "facilitating the exploitation of the species at an ideal fish size". I suggest rewording as follows:
"In order to facilitate a sustainable exploitation of the species, it is advised to reduce fishing pressure on M. gulio.

Conclusions, lines 11-12: Amend as follows: "..., and the length at first capture is LOWER than the length at maturity,...".

Comments on the Quality of English Language

No English proofreading service was applied to improve the quality of English, despite my recommendation to do so.

This is a major flaw for this manuscript, so please try to address this issue.

Author Response

Please see the attachments.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

I want to thank the authors for having adequately addressed the issues I raised in my last revision.

My overall recommendation is that the manuscript can now be accepted after minor revisions.

To further improve clarity, I suggest making the following additional changes to the main text:

Lines 111-113. Consider rewording as follows: "The study of fish population dynamics is based on the measure of growth, mortality, and recruitment patterns, which are key parameters for assessing production rates."

Line 120. Replace "researched" with "assessed".

Lines 205-207. Consider rewording as follows: "The asymptotic length (L∞) and growth coefficient (K), were estimated at 183.23 mm and 0.31 yr−1, respectively, by using ELEFAN I in the FiSAT program."

Line 219. Delete ", respectively" at the end of the sentence.

Line 222.  Delete "from" after "ranging".

Line 225. Replace "...from different stretches..." with "...from lower stretches...".

Line 228. Replace "...from different stretches..." with "...from lower stretches...".

Lines 329-330. Replace "...along the various stretches..." with "...along the lower stretches...".

Lines 331-332. Replace "... a as 0.000002, and b at 3.370 from the length-weight relationship." with "..., and finally a and b from the length-weight relationship as 0.000002 and 3.370, respectively". 

 

 

Author Response

Stock status of two commercially important catfishes, Mystus gulio (Hamilton 1822), and Mystus cavasius (Hamilton 1822), in relation to environmental variables along the lower stretches of the river Ganga, India.

The manuscript has been further revised, all minor necessary corrections were made in the manuscript directly, and some marked with blue colour. Point-wise clarification provided hereby:

Comments Responses (I) Ensure all references are relevant to the content of the manuscript. All references are found relevant to the paper, any unnecessary references already deleted during first round of review as per the suggestions (II) Highlight any revisions to the manuscript, so editors and reviewers can see any changes made. All minor corrections were done in the manuscript itself, and few marks with blue color for the ready references, please (III) Provide a cover letter to respond to the reviewers’ comments and explain, point by point, the details of the manuscript revisions. Kindly find this as cover letter (IV) If the reviewer(s) recommended references, critically analyze them to ensure that their inclusion would enhance your manuscript. If you believe these references are unnecessary, you should not include them. Followed as suggested (V) If you found it impossible to address certain comments in the review reports, include an explanation in your appeal. All necessary corrections were done as per the suggestion in the final revised form. Looking forward for a positive response from your kind end, please.

Author Response File: Author Response.pdf