Freshwater Fishes of the State of Rio de Janeiro, Southeastern Brazil: Biogeographic and Diversity Patterns in a Historically Well-Sampled Territory

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper provides a comprehensive overview of fish diversity in Rio de Janeiro. It is an original work with a unique approach. While I have identified several significant issues in the text, I strongly encourage the authors to address these concerns to enable the manuscript’s publication. Although Rio de Janeiro has a long history of fish collection and study, few works have compiled this information and analyzed biodiversity patterns comprehensively. This paper accomplishes exactly that. I commend the authors for their work but highlight that there are important points that need to be addressed.

My three main concerns are:

1. Marine Species - I acknowledge that marine fish occasionally enter freshwater rivers; however, I suggest that the authors remove marine species from their list. It does not make sense to state that Rio de Janeiro has so few marine fish species when this issue is likely due to sampling problems. Exclude these and focus on the freshwater data to enhance the value of your findings.

2. Historical Citation of Records - The authors mention species for the state but do not attribute this information to any sources. For example, see how all records of the Amazon in Dagosta & de Pinna (2019) are cited in Dagosta & de Pinna (2017). Similarly, Langeani et al. (2007) ensure each record from the Upper Paraná has a voucher or reference. Understanding the history of each record, adding or removing species, etc., will be crucial. Although this may seem time-consuming, I am confident that a more complete inventory will result, relieving the authors of undue responsibility for records, which is neither fair nor desirable.

3. Incomplete Inventory - I briefly reviewed two of the richest fish families in RJ: Characidae and Loricariidae. Unfortunately, I found several missing species that should obviously be on the list, as their type locality is RJ. This indicates that the inventory is not yet mature and needs to be reviewed species by species from southeastern Brazil to verify occurrences. If the authors argue that the work is an inventory based solely on SpeciesLink records, it does not qualify as an inventory. A comprehensive inventory must cross-reference multiple sources of information: ichthyofaunal lists, catalogs, FishBase and CAS datasets, original descriptions, etc.

Again, I reiterate my support for the authors to publish this work. It will be a significant advancement in the understanding of the fish fauna of Rio de Janeiro.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The quality of the English does not raise major concerns. Although some sentences are not well constructed, this is not an issue in itself for publication

Author Response

Thanks for the suggestions given.
We improved the manuscript.

FD#1-Title adjusted to- Fishes in continental waters of the state of Rio de Janeiro, southeastern Brazil: biogeographic and diversity patterns in a historically well-sampled territory"
If marine fish are being discussed, why include "rivers" in the title? 
Authors answer- Marine species records were considered only for the populations found in continental waters, considering all those marine forms that enter the estuary and also those that are found inside rivers for almost 100 km upstream from mouth.

FD#2- Sentence changed as suggested.

Introduction
FD#3- citation added- Bizerril; Primo, 2004

FD#4- Last sentence of Introduction written as: 
This study highlights the rivers of Rio de Janeiro, identifies the respective basins in a terri-torial context, and evaluates the distribution patterns of their fish species, including the freshwater fish species and only those marine that enters the freshwater environments.

2. Materials and Methods
FD#5- Ronaldo

FD#6- river lines Ronaldo

FD#7- The authors do not explain the criteria used to consider a fish species as occurring in the waters of Rio de Janeiro. The list includes both marine and freshwater fish: why are both types included?
The reason for inclusion of marine fish species is added to the objectives, at the end of introduction section.

Results
FD#8- The sampling framework of the study has significant issues. Firstly, the paper should focus exclusively on specimens with coordinates within the state boundaries. The inclusion of marine fish in this work is therefore questionable. I recommend refining the definition of "marine fish," employing more precise categories as proposed by Myers in his divisions. Fishes not found in the rivers of Rio de Janeiro should be excluded from the list. For an example of how to evaluate freshwater fish diversity separately from marine fish, see the work of Oyakawa & Menezes (2011) for the state of São Paulo. I strongly advise that the authors make this distinction.
Authors answer- The present study evaluates all the fishes in continental waters.

FD#9- Fig. 4- ok. This subject will be explored in Discussion.

FD#10- To what could this growth be attributed? Do not overlook exploring these questions, as it will transform the paper from a descriptive account into a historical investigation of the topic.
Authors answer- The historical reasons regarding an increase of collection sampling in the territory are out of the scope of present contribution.

FD#11- I insist that the authors focus solely on species that are truly freshwater and occurring within the state. The record of only 152 marine fish species in the state is implausible; a single transect in Baia da Guanabara would likely yield more species than this. This number is less than half of what Menezes (2011) recorded for São Paulo. Consequently, this figure does not accurately represent the marine fish diversity of Rio de Janeiro and significantly undermines the manuscript’s credibility.
Sentence added to methodology: The study area excludes the three marine bays in the territory- Guanabara  (RH-5), Sepetiba  (RH-2) and Ilha Grande (RH-1). 

FD#12- changed- fig 6- Figure 6 kept with freshwater native species only.

FD#13- changed- Table informed as following the Eschmeyer's Catalog of Fishes order to list the species (the most actualized list available at Fricke, R., Eschmeyer, W. N. & Fong, J. D. 2024  ESCHMEYER'S CATALOG OF FISHES: GENERA/SPECIES BY FAMILY/SUBFAMILY. (http://researcharchive.calacademy.org/research/ichthyology/catalog/SpeciesByFamily.asp). Electronic version accessed 2nd Sept 2024.

FD#14- If the authors wish to position their work as an inventory of the freshwater ichthyofauna of Rio de Janeiro, they must acknowledge the historical context. It is absolutely necessary to give credit to those who recorded species in the state previously. I recommend consulting Langeani et al. (2007) for the Upper Paraná as an example. Acknowledging all previous fish surveys in the state will elevate the work to a historical compilation rather than a compilation based on SpeciesLink data.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

 

1-    I Suggest modifying the title of the manuscript to the “ Checklist of fish in  the state of Rio de Janeiro, southeastern  Brazil: biogeographic and diversity patterns in a historically  well-sampled territory”.

2-    the structure of the abstract is messy and it needs to be re-written again.

3-    The introduction is not written well, lacks to supported literature. The authors did not give more effort to the previous studies on fish fauna of Rio de Janeiro, giving short and no knowledge on the previous studies.

4-    The Materials and Methods: some parts are written well. The authors gave more attention to the hydrographic areas in Rio de Janeiro depending on the previous studies. As Rio de Janeiro is a state in Brazil, the authors did not provide a detailed map for whole Brazil map and highlighted Rio de Janeiro state in the map, this is very important to give the reader more clarification for the studies area.

5-    The results were clearly presented and the researchers tried to integrate all previous studies well

6-    The discussion needs more modifications, as the structure of some sentences is incoherent and confuses the reader. In addition, the discussion needs to be expanded so that the huge results discussed by the researchers are reviewed, as the researchers overlooked some fish species and focused on specific species in the discussion.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Thanks for the suggestions given.
We improved the manuscript.
1- The title was kept as suggested by Reviewer 1.
2- The abstract was improved. 
3- We added to Introduction a brief history of Ichthyology in Rio.
4- Figure 1 was improved to include the rivers and a small map locating Rio in Brazil and South America.
5- Thanks
6- Discussion improved, new literature added. 

Reviewer 3 Report

Comments and Suggestions for Authors

After reviewing the manuscript titled " Fishes and rivers of the state of Rio de Janeiro, southeastern Brazil: biogeographic and diversity patterns in a historically well-sampled territory " the authors investigated the biodiversity of fish in a comprehensive database of species collected over more than three centuries. This research is a fundamental and important study. Despite the authors' significant efforts in using comprehensive tools for investigated the biodiversity of fish using database. I found several mistakes and concept misunderstandings in this manuscript. The abstract section is dreadful and looks as though it has been written by an inexperienced team member, without scrutiny by the rest of the team. The abstract section will need to be rewritten to achieve clarity and give the reader the confidence that the manuscript is going to be worth reading. In the introduction, we also suggest that the author make significant revisions. The author has not provided a comprehensive overview of the Rio de Janeiro region, including the current state of research on fish taxonomy and phylogeography, the geographical distribution, and the hydrographic systems. Readers who are not familiar with this area will find it difficult to understand the research background. This foundational research is important, and there is no need to explain the significance of such studies. In the Materials and Methods section, the author's description of the study area (2.1. Study area) has become a list-like narration. We suggest making some adjustments and using diagrams or tables to present the information, which would make it easier for readers to follow. The author's explanation of the study area's map is quite poor. The map lacks any topographical features, yet the author discusses a significant amount of geographical information, such as the Paraíba Valley. We suggest combining Figures 1 to 4 into two figures, and Figure 8 must include the locations of all the geographical terms mentioned by the author in the text. In the Results section, Table 5 is excessively large. We recommend moving Table 5 to the appendix to prevent the main text from becoming too lengthy. In the Discussion section, we suggest that the author structure the discussion of species based on the life history of the fish. For example, freshwater fish can be discussed by dividing them into primary, secondary, and peripheral freshwater species, while marine fish should be discussed separately. Presenting the information by geographical region may lead to misunderstandings, as the zoogeographical distribution of marine fish is more challenging to represent. However, primary freshwater fish are more likely to exhibit clear zoogeographical patterns. The author must be improved by removing general statements and explaining really the results obtained and comparing these results with the other studies in Rio de Janeiro. This study is a very important piece of fundamental research, and we encourage the publication of such foundational scientific work. While reviewing the manuscript, I identified several critical issues that require the authors' careful attention, spanning both conceptual and technical aspects. The paper cannot be considered for acceptance until the English grammar and phrasing have been thoroughly revised by a native English speaker. I have tried to make my review as constructive as possible, with the hope that it will benefit the authors. In its current form, this manuscript does not meet the publication criteria and requires minor revision.

I don't have any minor suggestions.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Moderate editing of English language required.

Author Response

Abstract- improved.
Introduction- Overview of investigations in Rio de Janeiro added.
materials and methods
Study area- Text improved. A new map added, with topographic information and rivers.
Figures 1-4 reviewed and condensed.
Results
Table 5 listed as an appendix
Discussion
Marine fish records in continental waters removed form the analysis. 
Discussion improved.
Thanks for the suggestions.