Biodiversity of the Huautla Cave System, Oaxaca, Mexico

Round 1

Reviewer 1 Report

Cave biodiversity in mountain regions is not often published and taxonomic studies are needed. I appreciate the effort and support the publication of this paper. However, the way this paper is written doesn't do the content justice and calls for many improvements.  Here are a few bullet points to guide the improvements:

• the abstract and the text in general doesn't inform properly on what the paper is about. What is the aim of the paper? It also emphasis more on the cave and cave system rather than on the diversity of species and the complexity of their identification (in particular the abstract and the first half of the paper)
• as per above, there is a strong emphasis on the system itself with no clear content on how the biodiversity and the structure of the system are linked, why the structure matters and influences biodiversity and traits, etc
• it is unclear when and how the species you talk about were collected, which ones are new versus had been described before
• there is no discussion about what can explain the diversity in this cave system as compared to other caves, why taxonomic determination of these species is so difficult, etc
• the conservation section is totally irrelevant and could/should be greatly improved. Many species you have in your table seem to be endemic, which is worth a discussion, climate change is likely to cause great changes in environmental conditions, which might have huge consequences on cave biodiversity, etc. There is a lot you could be talking about in this section that would make the paper considerably more interesting. 

Author Response

the abstract and the text in general doesn't inform properly on what the paper is about. What is the aim of the paper? It also emphasis more on the cave and cave system rather than on the diversity of species and the complexity of their identification (in particular the abstract and the first half of the paper)

1. Introduction and abstract have been improved.

 

as per above, there is a strong emphasis on the system itself with no clear content on how the biodiversity and the structure of the system are linked, why the structure matters and influences biodiversity and traits, etc.

1. Such aspects are very important characteristics of the caves that actually are object of further research, since is very complicated to understand how such conditions are shaping the diversity and evolution of the species inside the cave, in one of our publications addressing the evolution of two species inhabiting the cave system we proposed possible evolution scenarios considering different conditions within the cave, however more studies are needed to better understand it as for example the approximate age of the system is still unknow, so this paper is more an invitation to future research rather than answering such interesting but complicated questions and out of the scope of this paper.

 

it is unclear when and how the species you talk about were collected, which ones are new versus had been described before

1. the table indicates the author/authors who described the species, any extra information on any species should be revised in the original description as this paper only list the number of species inhabiting the cave system. There are no new species described in this paper (only a list of species undescribed based on the records of collections) and those undescribed can be identified in the table by the lack of specific epithet and having only “sp.”.

 

there is no discussion about what can explain the diversity in this cave system as compared to other caves, why taxonomic determination of these species is so difficult, etc.

1. Comparisons of caves is extremely complex as every single cave is different, even tough conditions inside the caves seems similar, the patterns that promote speciation within caves are very unexplored topics that should be addressed with a proper methodology and falls outside of the scope of this paper.

 

the conservation section is totally irrelevant and could/should be greatly improved. Many species you have in your table seem to be endemic, which is worth a discussion, climate change is likely to cause great changes in environmental conditions, which might have huge consequences on cave biodiversity, etc. There is a lot you could be talking about in this section that would make the paper considerably more interesting. 

 

1. We differ with the reviewer in that the conservations sections is irrelevant, however we have improved and added more details to this section.

Author Response File: Author Response.docx

Reviewer 2 Report

In the attachments you will find all my detailed comments and corrections.

The paper is a nice contribution to the field. Huautla system is one of the most important caves in Mexico, so it is a welcome addition to have this review of its fauna. Paper is well presented. 

Detailed recommendation are given in the attached document. It requires some further proof-reading to correct English and grammar, as I am not a native English speaker. 

There are only two important things to improve. The first is that number of species varies throughout the paper. Numbers of 50, 40, 18, 31, 26 (or 27 according to my counting of the table), 8, 34 (or 35) are given for total number of cave species. While they may be reflecting differences between what is meant to be cave species, troglobites, species described vs species as of yet undescribed, and so on, it is not evident to the reader why in different sections different numbers are given.

The second is the format of the table. Font size has to be changed so as to fit the words inside. It may be that when the PDF was made it changed the table. Anyway, it has to be resolved either by the authors or by the editors. There are also some nomenclature not defined (TB, TP, SB) in the text.

All these are minor corrections, so I highly recommend this manuscript to be published.

Comments for author File: Comments.pdf

Author Response

Reviewer 2

 

We have accepted most suggestions provided by the reviewer except for those listed below:

 

I wonder if this statement is valid. In Elliot’s book regarding the Astyanax caves of Mexico, he has a table showing 20 described cave adapted species for the Sierra de El Abra cave system. This is more than the 18 described species for Huautla. El Abra has 306 cave species, 34 of which are troglobites or stygobites.

 

1. This could be a misunderstanding, since Sierra del Abra is considered as a cave region and not a System, there are some cave systems in the El Abra region but not all of the caves in this region are part of the same system, the definition for a cave system implies that the caves are connected (in this sense, by “human size” passages), despite that some cracks could be connecting multiple caves in the Sierra del Abra and fauna could move across that passages, this is still unknown, extensive exploration on that region have been performed before so it is very well know which caves belongs to a system and which caves not. As reference, the list of longest and deepest caves can be consulted in the NSS web page, as well as the catalogue of caves of the AMCS, in any of those are records for “El Abra cave system”.

 

You also have a contradiction. You say that it has the highest troglobite diversity… containing 50 species, with possibly 40 troglobites. It is unclear what the 50 and 40 means. Are the 50 cave species that include troglophile and troglobite? Re-word.

 

1. We meant 50 total species and from those 40 or more are troglobionts, we have modified the text accordingly and updated all the information on numbers so the text match the table.

 

Here I am also not in agreement. These numbers are for “Sistema Sabinos”. But this is only a single cave as explored by humans. The cave connects via sumps to Tinaja and many other caves in the El Abra. So in reality if you want to compare “Sistema Huautla”, it should not be compared against a single cave, but against the system of caves that make the Sierra de El Abra, with its 306 cave species.

 

1. Once again Sistema El Abra is not recognized as a cave system but as a cave Region, if we compare al the caves in a region including those not connected, for sure the numbers will be different, according with all expeditions and explorations on Sierra de El Abra not all caves in the region are connected, in fact, there are some caves in the Huautla region which are not considered as part of the cave system, in this manuscript, we are focusing in a system which can be considered as a single cave with multiple entrances.

 

The use of comma before “and” should be avoided when there are only two subjects. For three and more it is ok. Check throughout document as this appears to be a common mistake.

1. commas, have been revised accordingly, following grammar rules.

 

Revision instead of act?

1. The group was already revised and is known that those species belongs to a different group, is only a matter of waiting for a taxonomic “act”, i.e. a formal publication transferring the species and new taxonomic combinations, which were not done on the original revision.

 

Should this be a citation in the numbered system?

1. Citation refers to the authors of the genus, extra dot was deleted.

Author Response File: Author Response.docx

Reviewer 3 Report

In my opion you should work more with taxonomist to have a real knowledge of this amazing cave system. 

Author Response

In my opion you should work more with taxonomist to have a real knowledge of this amazing cave system. 

 

1. We have enough knowledge about taxonomy since the three authors of the paper have a PhD in Systematics and Taxonomy, together and separately we have described multiple taxa, including different genera and species in Mexico, USA and Central America, the Reviewer can easily consult this information by looking for our names in researchgate or google scholar. Additionally, multiple of the new species described in the recent years for the Sistema Huautla was work done by us and members of the Coleccion Nacional de Aracnidos (CNAN) at the Instituto de Biologia, UNAM. Additionally, we not only have described the species in the caves but also, we have collected, which means we have enough knowledge about the conditions and morphology of the caves in which this species inhabit.

 

As no additional comments/suggestions to the manuscript have been provided by the reviewer, no further comments are addressed.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have indeed improved the paper. However,

• the abstract still doesn’t inform on the aim of the paper, which is as far as I understand to highlight some of the biological diversity in this cave system and encourage more research
• in their answers to my second comment, the authors agree on the importance of the structure of the caves on the diversity, traits, etc and suggest that as no answer yet exists, there should be more research. However, nowhere in the paper, is there a “research agenda” or anything alike, be it a series of open questions that refer to existing knowledge. This is needed to make the paper interesting. Therefore, I would ask the authors to include a section developing an agenda with some references to existing knowledge (in this and/or other cave systems) that could guide the research
• regarding the lack of clarity as of when the data was collected, I suggest that the authors add the information they provide in their answer at the end of the last paragraph of the introduction, in which they now inform about the aim of the paper.
• The authors include the following in one of their answers “patterns that promote speciation within caves are very unexplored topics that should be addressed with a proper methodology and falls outside of the scope of this paper”. This is typically an example of research agenda that should be stated as such.
• The improvements to the section on conservation are a good start but this is not enough from my point of view. As per my previous comment, there is more you could say about the importance of research and conservation in view of climate change, etc.
• The paper should include a section containing the research agenda mentioned above, which is what will make this paper really interesting and cited.

Author Response

We thank all suggestions made by the reviewer. We accepted all suggestions direct on the manuscript.

Reviewer 3 Report

Dear authors, Your corrections have improved the former manuscript. Nevertheless in the future the biodivesity of this amazing cave system must be studied in all groups.

 

Author Response

We thank reviewer's comments.