Geographical Distribution of Mauremys sinensis, Mauremys reevesii, and Their Hybrids in South Korea

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Detailed comments are provided in the attached file. In particular, it is not clear how the current genetic study differs from the observational studies provided in a series of reports by the National Institute of Ecology. Were animals trapped concurrently with the observational studies or did trapping occur separately? The authors need to clarify the timeline for sample collection. 

Additionally, it is stated that 13 specimens were sampled and yet additional samples are provided in Figures 3 and 4 with no explanation of their source. It seems important information was provided in a preprint (https://www.biorxiv.org/content/10.1101/2023.12.21.572907v1.full) that was not included in the current manuscript.

Lastly, it is not apparent from the results provided that the 2 species are hybridizing in the wild. See comments in the Discussion section.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

No issues with the quality of English language in the manuscript.

Author Response

Thank you for your thoughtful feedback. We've carefully reviewed all of the comments raised by the reviewer. We've attached our responses to the comments as files. We've colored the revised sections in yellow in the text. Thank you.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Title

The title is scientifically accurate and clearly states the focus on the geographical distribution of the two turtle species and their hybrid. However, it could be more precise by specifying whether the study also considers the ecological, environmental, or genetic factors influencing this distribution.

Hybrid Specification: The title mentions "their hybrid," but it doesn't specify the hybrid name or how it is identified. If the hybrid is well-known and has a recognized name, it should be included.

Abstract

The abstract states that M. sinensis was introduced "presumably in 2012," which seems uncertain. Providing more precise information or clarifying the basis of this presumption would strengthen the scientific reliability.

The abstract mentions that M. sinensis and its hybrids could have a “devastating impact” on M. reevesii, but does not provide specifics on how this impact manifests (e.g., genetic dilution, competition). More detail would be beneficial.

The genetic analysis findings are mentioned but lack detail on the methods used or the significance of these findings in the broader context of the study. Including this could improve the abstract’s technical depth.

There is a slight inconsistency in the phrasing, such as in the sentence "field surveys were conducted at 47 sites in the habitats of M. sinensis and M. reevesii in South Korea." This could be streamlined to improve readability (e.g., "field surveys were conducted at 47 sites across M. sinensis and M. reevesii habitats in South Korea").

The punctuation and grammar are mostly correct, but some phrases are somewhat awkward, such as "hybrids likely originate from captive breeding." This could be rephrased to "the hybrids likely originated from captive breeding."

Introduction

The introduction provides a solid foundation for the study but lacks elements of innovation and critical analysis. The scientific content is sound but could benefit from more explicit discussion of the ecological impacts and significance of the research. Technically, the introduction is well-structured, though it could be made more cohesive and accessible. Grammatical and editorial issues are minor but should be addressed to enhance readability. Overall, the introduction is well-written but could be improved by sharpening the focus and emphasizing the study's novelty and importance.

Materials and Methods

The methods described for surveying turtle distribution, sampling hybrids, and conducting genetic analyses are generally sound. However, there is a lack of detail regarding the statistical methods used to analyze the data. For example, while sequence divergence and phylogenetic analyses are mentioned, the criteria for selecting the best-fit model for sequence evolution (T92 + G and T92 + G + I) should be explained more thoroughly. The absence of any discussion about potential sources of error or bias in the field surveys or genetic analyses also weakens the scientific rigor.

The description of the field survey methods is adequate but lacks specific details that could affect reproducibility. For instance, the specific environmental conditions during surveys (e.g., temperature, time of day) and how these conditions might influence turtle behavior and detection rates are not discussed. Additionally, the criteria for selecting the 48 survey sites could be elaborated on to clarify why these locations were chosen and how representative they are of the broader habitat range.

More information on the genetic analysis protocols, such as the concentration and quality control of DNA samples, would enhance reproducibility.

Results

The results section could include more quantitative data, such as the exact number of hybrids identified and the specific locations where they were found. Additionally, providing more detailed statistics, like the percentage of hybrid individuals in comparison to pure species, would make the data more informative.

There is some inconsistency in the presentation of the genetic results. The section mentions two distinct clades for COI analysis and three clades for R35, but it is unclear whether these correspond to the same sets of individuals or different samples. Clarifying this point would improve the coherence of the results.

Discussion

The discussion provides a summary of findings but lacks in-depth analysis or critical evaluation of the results. For example, while the study mentions the occurrence of hybrids, it does not explore the ecological or evolutionary implications of these hybrids on the native populations. Additionally, the discussion does not adequately address the potential consequences of releasing captive-bred hybrids into the wild, which could have significant implications for biodiversity and conservation efforts.

While the discussion touches on the potential impact of non-native species, it does not thoroughly review the existing literature on the subject. Including more references to studies that have documented similar issues in other regions would strengthen the discussion and provide a broader context for the findings.

The discussion uses terms like “EDS” (Ecological Disruptive Species) without defining them. It’s important to ensure that all technical terms are defined or explained when first introduced to avoid confusion, especially for readers who may not be familiar with the terminology.

The discussion mentions that no studies have been conducted on captive breeding of certain turtle species, but it does not explain why this is important or how it relates to the current study. Clarifying the relevance of this point would help to make the discussion more coherent.

The discussion contains some long, complex sentences that could be broken down into shorter, clearer statements. For example, the sentence "Non-native species disrupt native species diversity through competition, disease transmission, and hybridization with native species, increasing the risk of native species extinction and causing changes in ecosystem functions and service delivery" could be split into two or more sentences for better readability.

There are instances where the writing is somewhat vague or imprecise. For example, the phrase “practical management measures are needed immediately” could be more specific about what these measures should entail.

The discussion occasionally jumps between topics without clear transitions, making it harder to follow the logical flow. For example, the transition from discussing hybridization to the impact of non-native species is somewhat abrupt. Adding transitional sentences or reorganizing the content could improve the coherence of the section.

Conclusions

The conclusion proposes several management actions, such as designating priority conservation areas and implementing intensive management. However, the recommendations lack specificity and detail. For example, the suggestion to implement "seasonal management" is vague and does not explain which specific management actions should be taken during different seasons or how these actions would effectively address the identified issues.

The conclusion recommends intensive removal of M. sinensis and habitat restoration for M. reevesii, but it does not provide a strong scientific rationale or evidence to justify these actions. The conclusion should explain why these particular measures are necessary and how they will contribute to the conservation of M. reevesii or the overall ecosystem.

Terms like "more severe risk assessments" and "more active public outreach" are vague and not well-defined. The conclusion would benefit from clearer language that specifies what is meant by these terms and how they would be implemented.

the conclusion contains some long, complex sentences that could be simplified for better readability. For example, the sentence "In addition, direct and indirect monitoring of M. reevesii should be conducted in the future, using environmental DNA in addition to sightings and captive surveys at known M. reevesii sites, as this was not conducted in this study" could be broken down into two sentences to improve clarity.

Some sentences are somewhat repetitive, such as mentioning the need for "intensive management" multiple times without adding new information. Streamlining the text would make the conclusion more concise.

 

 

Comments on the Quality of English Language

Title

The title is scientifically accurate and clearly states the focus on the geographical distribution of the two turtle species and their hybrid. However, it could be more precise by specifying whether the study also considers the ecological, environmental, or genetic factors influencing this distribution.

Hybrid Specification: The title mentions "their hybrid," but it doesn't specify the hybrid name or how it is identified. If the hybrid is well-known and has a recognized name, it should be included.

Abstract

The abstract states that M. sinensis was introduced "presumably in 2012," which seems uncertain. Providing more precise information or clarifying the basis of this presumption would strengthen the scientific reliability.

The abstract mentions that M. sinensis and its hybrids could have a “devastating impact” on M. reevesii, but does not provide specifics on how this impact manifests (e.g., genetic dilution, competition). More detail would be beneficial.

The genetic analysis findings are mentioned but lack detail on the methods used or the significance of these findings in the broader context of the study. Including this could improve the abstract’s technical depth.

There is a slight inconsistency in the phrasing, such as in the sentence "field surveys were conducted at 47 sites in the habitats of M. sinensis and M. reevesii in South Korea." This could be streamlined to improve readability (e.g., "field surveys were conducted at 47 sites across M. sinensis and M. reevesii habitats in South Korea").

The punctuation and grammar are mostly correct, but some phrases are somewhat awkward, such as "hybrids likely originate from captive breeding." This could be rephrased to "the hybrids likely originated from captive breeding."

Introduction

The introduction provides a solid foundation for the study but lacks elements of innovation and critical analysis. The scientific content is sound but could benefit from more explicit discussion of the ecological impacts and significance of the research. Technically, the introduction is well-structured, though it could be made more cohesive and accessible. Grammatical and editorial issues are minor but should be addressed to enhance readability. Overall, the introduction is well-written but could be improved by sharpening the focus and emphasizing the study's novelty and importance.

Materials and Methods

The methods described for surveying turtle distribution, sampling hybrids, and conducting genetic analyses are generally sound. However, there is a lack of detail regarding the statistical methods used to analyze the data. For example, while sequence divergence and phylogenetic analyses are mentioned, the criteria for selecting the best-fit model for sequence evolution (T92 + G and T92 + G + I) should be explained more thoroughly. The absence of any discussion about potential sources of error or bias in the field surveys or genetic analyses also weakens the scientific rigor.

The description of the field survey methods is adequate but lacks specific details that could affect reproducibility. For instance, the specific environmental conditions during surveys (e.g., temperature, time of day) and how these conditions might influence turtle behavior and detection rates are not discussed. Additionally, the criteria for selecting the 48 survey sites could be elaborated on to clarify why these locations were chosen and how representative they are of the broader habitat range.

More information on the genetic analysis protocols, such as the concentration and quality control of DNA samples, would enhance reproducibility.

Results

The results section could include more quantitative data, such as the exact number of hybrids identified and the specific locations where they were found. Additionally, providing more detailed statistics, like the percentage of hybrid individuals in comparison to pure species, would make the data more informative.

There is some inconsistency in the presentation of the genetic results. The section mentions two distinct clades for COI analysis and three clades for R35, but it is unclear whether these correspond to the same sets of individuals or different samples. Clarifying this point would improve the coherence of the results.

Discussion

The discussion provides a summary of findings but lacks in-depth analysis or critical evaluation of the results. For example, while the study mentions the occurrence of hybrids, it does not explore the ecological or evolutionary implications of these hybrids on the native populations. Additionally, the discussion does not adequately address the potential consequences of releasing captive-bred hybrids into the wild, which could have significant implications for biodiversity and conservation efforts.

While the discussion touches on the potential impact of non-native species, it does not thoroughly review the existing literature on the subject. Including more references to studies that have documented similar issues in other regions would strengthen the discussion and provide a broader context for the findings.

The discussion uses terms like “EDS” (Ecological Disruptive Species) without defining them. It’s important to ensure that all technical terms are defined or explained when first introduced to avoid confusion, especially for readers who may not be familiar with the terminology.

The discussion mentions that no studies have been conducted on captive breeding of certain turtle species, but it does not explain why this is important or how it relates to the current study. Clarifying the relevance of this point would help to make the discussion more coherent.

The discussion contains some long, complex sentences that could be broken down into shorter, clearer statements. For example, the sentence "Non-native species disrupt native species diversity through competition, disease transmission, and hybridization with native species, increasing the risk of native species extinction and causing changes in ecosystem functions and service delivery" could be split into two or more sentences for better readability.

There are instances where the writing is somewhat vague or imprecise. For example, the phrase “practical management measures are needed immediately” could be more specific about what these measures should entail.

The discussion occasionally jumps between topics without clear transitions, making it harder to follow the logical flow. For example, the transition from discussing hybridization to the impact of non-native species is somewhat abrupt. Adding transitional sentences or reorganizing the content could improve the coherence of the section.

Conclusions

The conclusion proposes several management actions, such as designating priority conservation areas and implementing intensive management. However, the recommendations lack specificity and detail. For example, the suggestion to implement "seasonal management" is vague and does not explain which specific management actions should be taken during different seasons or how these actions would effectively address the identified issues.

The conclusion recommends intensive removal of M. sinensis and habitat restoration for M. reevesii, but it does not provide a strong scientific rationale or evidence to justify these actions. The conclusion should explain why these particular measures are necessary and how they will contribute to the conservation of M. reevesii or the overall ecosystem.

Terms like "more severe risk assessments" and "more active public outreach" are vague and not well-defined. The conclusion would benefit from clearer language that specifies what is meant by these terms and how they would be implemented.

the conclusion contains some long, complex sentences that could be simplified for better readability. For example, the sentence "In addition, direct and indirect monitoring of M. reevesii should be conducted in the future, using environmental DNA in addition to sightings and captive surveys at known M. reevesii sites, as this was not conducted in this study" could be broken down into two sentences to improve clarity.

Some sentences are somewhat repetitive, such as mentioning the need for "intensive management" multiple times without adding new information. Streamlining the text would make the conclusion more concise.

 

 

Author Response

Thank you for your thoughtful feedback. We've carefully reviewed all of the comments raised by the reviewer. We've attached our responses to the comments as files. We've colored the revised sections in yellow in the text. Thank you.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

This article describes about two turtles namely Mauremys sinensis and  Mauremys  reevesii in South Korea.  Mauremys sinensis is believed to be exotic to the country and spread over all niche.

Introduction

It is unnecessarily large and describe many text book knowledge. Leave them to 3-4 para 1) Just concentrate on the two species in one para, 2) then their international status and status in South Korea, 3) then what are the need of such research, gap and your hypothesis.

Please be careful to look into the above points.

2.  Materials methods

  Mention how sampling was done and what sampling method was followed in field.

Rest part is ok

Discussion

Some of the discussion part may be included towards the other similar species.  

Author Response

Thank you for your novel comment. We carefully considered all the comments that were raised by the reviewer. We've included the edited sections in yellow in the text.

Comments 1: Introduction: It is unnecessarily large and describe many text book knowledge. Leave them to 3-4 para 1) Just concentrate on the two species in one para, 2) then their international status and status in South Korea, 3) then what are the need of such research, gap and your hypothesis. Please be careful to look into the above points.

Response 1: We've rewritten the introduction in response to reviewer comments.

Comments 2. Materials methods: Mention how sampling was done and what sampling method was followed in field.

Response 2: We've added additional sampling methods based on reviewer comments.

Comments 3. Discussion: Some of the discussion part may be included towards the other similar species.

Response 3: We've rewritten the discussion section in response to reviewer comments and made some changes.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

no comments.