Age and Growth of Hedinichthys yarkandensis (Day, 1877) in the Hotan River

Round 1

Reviewer 1 Report (New Reviewer)

REVIEWER’S COMMENTS

The manuscript (MS) is well written and scientifically sound. It provides a good insight into the role of habitat characteristics in structuring the otolith morphology of fishes by describing the age and growth characteristics of the endemic freshwater loach, Hedinichthys yarkandensis (previously known as Triplophysa yarkandensis), in the Hotan River, which is a part of the Tarim River basin of China. With the increasing global concern regarding the protection and conservation of endemic freshwater fishes, the paper is of good relevance. The MS can be accepted for publication after incorporating the following suggestions:

1.      Whenever we formulate a research paper related to a single species, we should follow the updated scientific name of the species. The revised name of the species as per the Catalog of Fishes (which is accepted worldwide) is Hedinichthys yarkandensis (Day 1877). The way the fish species name is provided in the title of MS is scientifically incorrect. Please follow the updated name, H. yarkandensis throughout the MS. You can just mention in the introduction part that its previous name was Triplophysa yarkandensis.

2.      There is some confusion with regard to wildlife law in China in the introduction part, especially the class I and class II (or first class or second class) protected wildlife. Please mention the legally correct name in this regard. I have given specific comments in the main MS.

3.      In the figure representing the various morphological measurements (Figure 2) followed in the study, the body width is not depicted in the figure. Either you provide two different view of the fish species to demarcate the morphological parameter or remove the word body width from the figure title. With regard to the term body length as represented in the figure, the term 'standard length’ is the correct terminology.

4.      Though the otolith measurement terms are mentioned in the methodology part, it is always better to provide the abbreviations as a footnote in Table 4 for easier understanding.

5.      Please provide the reference for the formula on Marginal Increment Ratio (MIR) and Fulton’s condition index used in the study.

6.      Line nos. 330 – 337 – The authors have related the early sexual maturity attained by males of H. yarkandensis to salinity, sand content and water volume. Is there any previous study on this regard? Such statements should be supported by proper references.

A major query to the authors is regarding the subject area of the paper with respect to the aims and scope of the journal. Kindly go through the aims-and-scope and suggest how best the present manuscript will fit to this?

My submissions to the authors are as follows:

Abstract:  Authors can assess the growth pattern and sex ratio of Triplophysa (Hedinichthys) yarkandensis and include it in the abstract

Introduction:

·         Suggest improving the introduction with more focus on the population parameter study on the species group and fish and fisheries of the Hotan River.

·         Please provide information about the current status of T. yarkandensis production.

·         In light of general comments, re-organize the objectives with respect to results. Give the full name of the species at the time of the first mention.

Materials and Method:

·         The details of the sampling site and site description details should be given under the study area description and the author may add the land use pattern of sampling sites for understanding the ecology.

·         For population or Age and growth study monthly sampling is required to get a clear structure of population detail, that is missing. Seasons should be mentioned clearly (Starting and ending month with the name of the season) in the methods.

·         Statistical validation is required for the population parameters like the t-test, the chi-square test also needs to carryout for validating the sex ratio of the population. Please add the details under the statistical analysis section.

Result:

·         Since all population parameters were assessed for both sex, authors should mention the number of specimens collected from each sex in the methodology and calculate the sex ratio.

·         Authors can estimate the K and mortality value of the different sex of T. yarkandensis and can include it in the result.

·         The derivatives are unnecessary under the growth equation result section.

·         Please provide good-quality figures for the improvement of the manuscript.

·         There is no description of the stock and MSY estimation, without such analysis how author can get the current population structure, and what base regulation will make?

Discussion:

·         Authors are requested to refer to recent publications to the related study and use them in the manuscript.

·         Since there are more previous studies on Triplophysa sp taken place, I suggest authors can add explanatory variables (e.g. intensity of pressure, season, etc) to Justify your work

·         Discussion part needs to focus on justifying the present result and also provide the reason for the deviation of the current results from other studies.

Conclusion:

·         Authors are requested to add the conclusion part with the recommendation to retain the population of Triplophysa (Hedinichthys) yarkandensis.

Reference:

·         Reference in the text as well as in the reference part should follow the Journal format.

Good

Author Response

Response to Reviewer 1 Comments

The manuscript (MS) is well written and scientifically sound. It provides a good insight into the role of habitat characteristics in structuring the otolith morphology of fishes by describing the age and growth characteristics of the endemic freshwater loach, Hedinichthys yarkandensis (previously known as Triplophysa yarkandensis), in the Hotan River, which is a part of the Tarim River basin of China. With the increasing global concern regarding the protection and conservation of endemic freshwater fishes, the paper is of good relevance. The MS can be accepted for publication after incorporating the following suggestions:

1. Whenever we formulate a research paper related to a single species, we should follow the updated scientific name of the species. The revised name of the species as per the Catalog of Fishes (which is accepted worldwide) isHedinichthys yarkandensis(Day 1877). The way the fish species name is provided in the title of MS is scientifically incorrect. Please follow the updated name,  yarkandensis throughout the MS. You can just mention in the introduction part that its previous name was Triplophysa yarkandensis..

Response 1: Changes have been made in response to comments

2. There is some confusion with regard to wildlife law in China in the introduction part, especially the class I and class II (or first class or second class) protected wildlife. Please mention the legally correct name in this regard. I have given specific comments in the main MS.

Response 2: I'm sorry I didn't find a specific comment in the MS, but I've reworked the relevant narrative: The protection level of wildlife is divided into national key protection, provincial key protection wildlife, and provincial general protection wildlife. Hedinichthys yarkandensis (Day, 1877), an endemic fish of the Tarim River system, is a class II key protected aquatic wildlife in Xinjiang Uygur Autonomous Region

3.In the figure representing the various morphological measurements (Figure 2) followed in the study, the body width is not depicted in the figure. Either you provide two different view of the fish species to demarcate the morphological parameter or remove the word body width from the figure title. With regard to the term body length as represented in the figure, the term 'standard length’ is the correct terminology.

Response 3: Changes have been made in response to comments. Images involving changes that need to be made have been re-uploaded

4.Though the otolith measurement terms are mentioned in the methodology part, it is always better to provide the abbreviations as a footnote in Table 4 for easier understanding.

Response 4: Changes have been made in response to comments

5. Please provide the reference for the formula on Marginal Increment Ratio (MIR) and Fulton’s condition index used in the study.

Response 5: Reference additions have been completed in the first place, and the second place has appeared in the original manuscript

6. Line nos. 330 – 337 – The authors have related the early sexual maturity attained by males of yarkandensis to salinity, sand content and water volume. Is there any previous study on this regard? Such statements should be supported by proper references..Line nos. 330 - 337.

Response 6: The H. yarkandensis showed early sexual maturity in the face of the degraded water environment of the Tarim River, which is degraded mainly in terms of salinity, sand content and water volume. Relevant references have been inserted.

A major query to the authors is regarding the subject area of the paper with respect to the aims and scope of the journal. Kindly go through the aims-and-scope and suggest how best the present manuscript will fit to this?

Response 7: Due to the uplift of the Tibetan Plateau, the Tarim was uplifted from the original ocean into a basin, from which the Tarim River system formed a special ecosystem surrounding the Taklamakan Desert in an encircling type, which is of great significance for the formation of special ecological characteristics of plateau fishes and the formation of biological and cultural diversity in the Tarim. So I think it is accurate and appropriate for this article to be submitted to this special issue, because the rivers in the Xinjiang region covered in it have idiosyncratic habitat characteristics that are more prominently characterized by Effect of Aquatic Environment on Fish Ecology, which matches the keyword: fish growth, environmental stress.

My submissions to the authors are as follows:

Abstract:Authors can assess the growth pattern and sex ratio of Triplophysa (Hedinichthys) yarkandensis and include it in the abstract

Response 8: Sex ratios were added to the summary and growth patterns were already present

Introduction:

Suggest improving the introduction with more focus on the population parameter study on the species group and fish and fisheries of the Hotan River.

Please provide information about the current status of T. yarkandensis production.

In light of general comments, re-organize the objectives with respect to results. Give the full name of the species at the time of the first mention.

Response 9: The introduction has been reorganized and revised as required.

Materials and Method:

The details of the sampling site and site description details should be given under the study area description and the author may add the land use pattern of sampling sites for understanding the ecology.

Response 10: Sampling point information has been supplemented in accordance with the proposed changes：The selected site is near the Red and White Mountains on the west bank of the lower Hotan River, which has a typical desert climate.

For population or Age and growth study monthly sampling is required to get a clear structure of population detail, that is missing. Seasons should be mentioned clearly (Starting and ending month with the name of the season) in the methods.

Response 11: This study was collected according to each quarter and the relevant information is shown in Table 1.

Statistical validation is required for the population parameters like the t-test, the chi-square test also needs to carryout for validating the sex ratio of the population. Please add the details under the statistical analysis section.

Response 12: Changes have been completed as required.

Result:

Since all population parameters were assessed for both sex, authors should mention the number of specimens collected from each sex in the methodology and calculate the sex ratio.

Response 13: The gender ratio of the sample was added to this section of sample collection: It was determined that the gender ratio of the sample was 0.87:1.

Authors can estimate the K and mortality value of the different sex of T. yarkandensis and can include it in the result.

Response 14: Reference has been made to this section in the original text: The mean fulton condition index of males and females was 1.4654 and 1.4416. This study focuses on population growth and has not yet addressed population dynamics, so a mortality value was not included

The derivatives are unnecessary under the growth equation result section.

Response 15: To cover the three parts, change the title of 1.6 and 2.7 to Growth equations, growth rate and growth acceleration equations

Please provide good-quality figures for the improvement of the manuscript.

Response 16: All images in the text are vectorial inserts.

There is no description of the stock and MSY estimation, without such analysis how author can get the current population structure, and what base regulation will make?

Response 17: Stock dynamics assessment and fisheries management have not been addressed in this study, and stock structure has been studied based on its age and growth.

Discussion:

Authors are requested to refer to recent publications to the related study and use them in the manuscript.

Response 18: References have been corrected as required.

Since there are more previous studies on Triplophysa sp taken place, I suggest authors can add explanatory variables (e.g. intensity of pressure, season, etc) to Justify your work.

Response 19: Most of the literature primarily referenced was sampled on a seasonal cycle, and no inter-seasonal comparisons were conducted; because the watersheds involved were too large to summarize accurate environmental characterization values, but in the article for the comparison of growth parameters of H. yarkandensis in the three rivers, reference was made to the associated stresses

Discussion part needs to focus on justifying the present result and also provide the reason for the deviation of the current results from other studies.

Response 20: The reasons for the deviation of the current results from those of other studies in section 3.1 have been added as requested: The age of sexual maturity may be earlier with signs of early maturity, which may be closely related to the trend of population miniaturization exacerbated by water degradation in the Tarim River. The young age of the Tarim River population is closely related to the increase in the salinity, sand content and water volume of the Tarim River in recent years, as well as the influence of human activities. The young age of the Yarkand River population has been influenced by the excessive construction of water hubs along the basin, the canalization of rivers, the continuous increase in the area of cultivated land in the basin, and the introduction of exotic species.

The reasons for the deviation of the current results from the results of other studies in section 3.2 have been explained in the original text in terms of interregional macro characteristics: This was closely related to the fact that the Hotan River flows through the Taklamakan Desert, which has little human activity and a more stable water ecosystem. In addition, the feeding needs of H. yarkandensis were guaranteed to some extent by bait organisms.

Conclusion:

Authors are requested to add the conclusion part with the recommendation to retain the population of Triplophysa (Hedinichthys) yarkandensis.

Response 21: Changes have been completed as suggested.

Reference:

Reference in the text as well as in the reference part should follow the Journal format.

Response 22: Changes have been completed as suggested.

Author Response File: Author Response.docx

Reviewer 2 Report (New Reviewer)

1. line 48-55: the information about sample site settings, frequency need to be presented more detailly.

2. Fig. 1,  4-11 should be improved, the  current resolution of these figures are too low.

3. The abscissa of Fig. 8 is preosent by month, however there are 13 months listed, it is not correct.

4. The discussion section is too cumbersome and needs to be streamlined and condensed.

5. In the reference section, there are light gray background for several listed papers, please remove them.

 

The overall quality of this manuscript is good, however minor editing of English language required in some parts.

Author Response

Response to Reviewer 2 Comments

1. line 48-55: the information about sample site settings, frequency need to be presented more detailly.

Response 1: Sample information has been supplemented as suggested.

2. 1,4-11 should be improved, the current resolution of these figures are too low.

Response 2: All images in the text are vectorial inserts. Or do I need to size it up?

3. The abscissa of Fig. 8 is preosent by month, however there are 13 months listed, it is not correct.

Response 3: Changes have been made to the pictures as suggested.

4. The discussion section is too cumbersome and needs to be streamlined and condensed.

Response 4: Changes have been made to the discussion section as suggested.

5. In the reference section, there are light gray background for several listed papers, please remove them.

Response 5: Changes have been completed as suggested

Author Response File: Author Response.docx

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.

Round 1

Reviewer 1 Report

The work "Age and growth of Triplophysa (Hedinichthys) yarkandensis (Day, 1877) in the Hotan River" by Xinyue et al., shows the growth and age of this species in a Grade II protected habitat. I have several concerns related with the "lack" of ambition of this work and other details, which I explain below.

- It should be added the country where Hotan River is located. A map of the sampled area could help as well.

- It should be explained what "Grade II" mean since it is not easily acknowledged by many readers how protected areas ranks are described in China.

- I have some ethical concerns regarding the overall number of "protected" fish killed for this work (1275). I think the work could be enriched with genetic analysis since such a huge number of fish were collected.

Other details:

Check overall formatting. E.g.: space (" ") before brackets ("(") should be consistent.

Several concepts should be revised (e.g.: "fullness" vs Fulton condition index)

Line 67 vs Line 135: relatively large or tiny?

Line 68: detail how many left/right otholits you use for such comparison.

Reviewer 2 Report

There are low leve lof clarity along the lecture of the manuscript such as:

1.       It is necessary to explicit the objetive in the Abstract section.

2.       “This study explored the age structure and growth characteristics of T. yarkandensis in the Hotan River based on fish ecology using continuous periodic sampling. The purpose was to analyze and evaluate the trend of fish population changes and to provide theoretical support for subsequent proliferation and conservation work.” What does “the trend of fish population changes“ mean?

3.       It is necessary to show the number of specimens sample by month, this is a must in growth analysis.

4.       Why do the otoliths were stored in PCR tubes containing 95% etanol?

5.       Table 1 should be organized by sampling time, the table is not clear at all with respecto f sampling time and site.

6.       “There was no significant difference between the left and right otoliths” differences in what?

7.       “The age was determined based on the number of annual whorls” A image is necessary to show the anual marks.

8.       “The left otolith was consistently employed in this investigation because the paired 141 sample t-test revealed no significant difference between the morphology of the left” what is the analysis that authors used to compare “the morphology”’ what is the morphology?

9.       Fig. 2 has not quality.

10.   Body length distribution (with all especimens) do not have any sense in this study.

11.   What do “fullness” mean? Which index?, b?

12. Figures quality is fatal, no clarity in lines and words.

Reviewer 3 Report

The language must be significantly improved and terminology must follow ichthyological journals. Figures are unclear and redundant. If you have determined the sex of the fish, you don't need to put total of population in figure. It would be nice to know min and max of weight and length of each age group, not just mean and S.D. When you determine age you have to do it with two independent observers.