Echinoids and Crinoids from Terra Nova Bay (Ross Sea) Based on a Reverse Taxonomy Approach

Round 1

Reviewer 1 Report

The submited manuscript is certainly of interest to a wide range of researchers and touches on the topical issue of verification of species identifications. The authors have carried out a great deal of work comparing morphological and molecular genetic approaches to the description of species diversity on the example of two groups of Antarctic echinoderms. The work certainly deserves to be published after the revision. Detailed notes in the attached file.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer,
Thank you for your feedback on our manuscript. We appreciate your insightful comments and suggestions for further improvement.
Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear authors, this MS provides some original and interesting data on integrated taxonomy using classical morphological approaches and DNA barcoding based on COI1. It is of broad interest and especially relevant for the scope of the Journal and contemporary, as much effort and research is currently ongoing to compile the barcoding of life using museum and newly sampled biological material.

Although it definitely deserves publication, the MS has some issues that needs to be addressed. In general, the authors failed to show and discuss the linkage or the complementarity of the two different taxonomical approaches. A linguistic revision is definitely needed, as many sentences are too long and hard to understand. Moreover, the MS contains too much unnecessary information that should be moved to supplementary material. I am also surprised by the very large number of references used in this work.

More specifically,

- The Abstract is too long and has to be shortened to 200 words following the guidelines of the Journal. The general information included in the first sentences should be limited to one sentence introducing to the scope of the MS. More importantly, it should be clear the different results obtained by using conventional and DNA barcoding approach to biodiversity.

- I strongly suggest avoid using first person all over the MS

 - Acronyms should be defined, and then, used all over the text.

- The second sentence of the first paragraph in the introduction is irrelevant.

- Data on field sampling, collections and expeditions should be presented as supplementary material. Only as synopsis is necessary so the reader could be informed on sampling effort and replication.

- I also didn’t understand well the design, if the authors collected material from the museum, shy they should give all these details on samplings. A brief Table in supplementary material would be much more informative and easy to follow.

- After the definition of what COI is don’t use again the full name.

- Table 1 needs additional explanations, why all sample vouchers are included, also, this material has not been identified prior to DNA barcoding? Why these data are not presented, or at least classified according to class; and how these samples have been collected? This is not clear in the methodology.

- The letters in Figure 1 are confusing, the way of collection is not relevant, and this figure is repetitive with Table 1; I suggest to keep a modified Figure in the text and move the Table in supplementary material.

- Table 2 is repetitive with text lines 149-150.

- There is no need to include references in the legend of Figure 2, the methods have been described in the text

- Figure 2, which is the most important results is unreadable, it should be somehow enlarged so the reader could be informed

- Why details on samples are included in Table 3/Figure 4/5, move this information in the supplementary material

- Why results on conventional morphological identification of specimens has not been provided?

- A large part of the MS included in the results it fits better to the methodology, i.e. section 3.2; in the results only the finding should be presented

- I am confused again; conventional taxonomy has been made prior or after DNA barcoding?

- Figure 3 does not present morphological variability, it shows the DNA results and representative photos of those species, why not all species included here?

- Figure 4, same as Figure 3

- Since the full name of the species has been given, there is no need to repeat the full name in Figures, Tables, text, including the nominator

- The discussion is extremely brief, it should be deepen, emphasizing on the linkage between the applied approaches. The most important is to show the gaps filled by DNA and the pitfalls/limitation of each approach. Which were the cryptic species revealed by the present study?

- I strongly suggest to compile an identification key based on the applied morphological analysis, in order to facilitate future studies

- The last sentence of the discussion look like an acknowledgment of funding, is irrelevant.

- Finally, there are too many references, and so, I suggest to eliminate unnecessary ones.

A thorough linguistic revision is needed. The text is hard too read and has too long sentences all over.

Author Response

Dear Reviewer,
Thank you for your feedback on our manuscript. We appreciate your insightful comments and suggestions for further improvement.
Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear autors
I think the manuscript is better now and can be published.

Author Response

Please see the attachment

Reviewer 2 Report

Dear authors, indeed the revised version of your MS has been much improved, however I still believe that

- References should be revised and only necessary ones documenting methods and discussion should be kept,

- The discussion has been expanded, but contains repetitive and a little vague information on reverse taxonomy; I suggest to revise and shorten this part keeping a firm documentation of advantages

- I insist to delete the last sentence of discussion as irrelevant to this section

- Provide credits for the photos of species

- Revise text and formatting (needs some minor corrections as it is rather "harshly" prepared)

- Morphological results should be presented in a Table

- Sampling gear details should be deleted from text, as information on the type of gear used is included in the revised Table 1

Minor linguistic revision is still needed

Author Response

Please see the attachment

Author Response File: Author Response.pdf