Next Article in Journal
Molecular Detection and Genotyping of Enteric Protists in Asymptomatic Schoolchildren and Their Legal Guardians in Madrid, Spain
Previous Article in Journal
Lice, Flies, Mites, and Ticks on Raptors (Accipitriformes, Falconiformes and Strigiformes) in Rescue Centers in Central Italy
 
 
Article
Peer-Review Record

Environmental Correlates of Prevalence of an Intraerythrocytic Apicomplexan Infecting Caribbean Damselfish

by Akacia K. Halliday-Isaac 1, Jennilee B. Robinson 2, Edwin Cruz-Rivera 1,2, Andrew G. Campbell 3 and Paul C. Sikkel 4,5,*
Reviewer 1: Anonymous
Reviewer 2: Anonymous
Submission received: 28 February 2021 / Revised: 22 April 2021 / Accepted: 23 April 2021 / Published: 2 May 2021

Round 1

Reviewer 1 Report

The authors survey 387 Stegastus adustus for an Haemohormidium‐like apicomplexan blood parasite at 30 sites around the U.S. Virgin Islands. The evaluated the relationship between several environmental and biological predictors and infection prevalence. They further evaluated a subset of the infected and uninfected fish for evidence of a relationship between host condition and parasite status. They found a range of infection at individual sites from 0 to 87% infection prevalence, and found that S. adustus density and north-south shallow currents were associated with infection prevalence. They found no effect of infection on body condition or leukocyte counts of the host.

 

I think this was a well written manuscript that describes interesting and well-done research. I provide a few minor comments below that could improve the manuscript, but on the whole I found this a joy to read.

Line 48-54: It could be worth mentioning that tolerance to infection could lead to positive correlations between host fitness and infection:

Budischak, S. A., D. O’Neal, A. E. Jolles, and V. O. Ezenwa. 2018. Differential host responses to parasitism shape divergent fitness costs of infection. Functional Ecology 32:324–333.

 

Figure 100-102: Should list be for Fig. A2?  I am curious about why there is both an appendix and a supplement for this paper.  

 

Line 105-106: It is fascinating that your initial screening found so many infected individuals that had such low screening.  Do you have an idea for why this happened?  For example, do you have a reason to think that your initial screening was better at detecting infected cells then the additional screening?

 

Line 119-120: There was clearly a lot of variability in the leukocytes between infected fish, and it appears that the uninfected fish had less variability in leukocyte counts. Have you explored whether other variables (e.g. fish size, body condition, etc) are related to the increased variance you see in the leukocyte counts in infected fish?

 

Line 193: Out of curiosity, do you have an idea why the east-west flows didn’t have an effect but the north-south flows do?

 

Line 211-213: I think it would make sense to tone down the statements in this section.  While female size is linked to fecundity, I would imagine that it isn’t the only link to fecundity (as discussed further along in the paragraph, line 222-2240.  So, while it is fair to say that the parasite might not be influencing fecundity through the mechanisms associated with female size, there are other possible mechanisms for influencing fecundity that haven’t been measured.

 

Line 225-227: Interesting point, I like how you discuss this here.

 

 

 

Author Response

The authors survey 387 Stegastus adustus for an Haemohormidium‐like apicomplexan blood parasite at 30 sites around the U.S. Virgin Islands. The evaluated the relationship between several environmental and biological predictors and infection prevalence. They further evaluated a subset of the infected and uninfected fish for evidence of a relationship between host condition and parasite status. They found a range of infection at individual sites from 0 to 87% infection prevalence, and found that S. adustus density and north-south shallow currents were associated with infection prevalence. They found no effect of infection on body condition or leukocyte counts of the host.

 I think this was a well written manuscript that describes interesting and well-done research. I provide a few minor comments below that could improve the manuscript, but on the whole I found this a joy to read.

Line 48-54: It could be worth mentioning that tolerance to infection could lead to positive correlations between host fitness and infection:

Budischak, S. A., D. O’Neal, A. E. Jolles, and V. O. Ezenwa. 2018. Differential host responses to parasitism shape divergent fitness costs of infection. Functional Ecology 32:324–333.

This is a very good point and has been added to the Discussion.

 Figure 100-102: Should list be for Fig. A2?  I am curious about why there is both an appendix and a supplement for this paper.  

The material in the Supplement was deemed too detailed to place in the Appendix. We have therefore kept it as a Supplement. However, we are willing to abide by the Editor’s recommendation.

 Line 105-106: It is fascinating that your initial screening found so many infected individuals that had such low screening.  Do you have an idea for why this happened?  For example, do you have a reason to think that your initial screening was better at detecting infected cells then the additional screening?

Initial screening was done for a 40 min timed period to make sure we did not mis-classify infected and uninfected individuals. Quantification was done using a fixed number of photographs and thus a much lower percentage of the blood smear on the slide. Thus, for low level infections, it is indeed likely that no infected cells would have been found in these subsamples.

 Line 119-120: There was clearly a lot of variability in the leukocytes between infected fish, and it appears that the uninfected fish had less variability in leukocyte counts. Have you explored whether other variables (e.g. fish size, body condition, etc) are related to the increased variance you see in the leukocyte counts in infected fish?

This is a very good point. We have included additional analyses of these data which we feel does a much better job of elucidating the patterns.

 Line 193: Out of curiosity, do you have an idea why the east-west flows didn’t have an effect but the north-south flows do?

We can only speculate and have included presentation of possible explanations in the Discussion.

 Line 211-213: I think it would make sense to tone down the statements in this section.  While female size is linked to fecundity, I would imagine that it isn’t the only link to fecundity (as discussed further along in the paragraph, line 222-2240.  So, while it is fair to say that the parasite might not be influencing fecundity through the mechanisms associated with female size, there are other possible mechanisms for influencing fecundity that haven’t been measured.

Very good point. This section has been rewritten.

 Line 225-227: Interesting point, I like how you discuss this here.

Thank you.

Reviewer 2 Report

Dear Editor

the manuscript “Environmental correlates of prevalence of an intraerythrocytic apicomplexan infecting Caribbean damselfish” deals with a subject that deserves to be published after minor revisions.

 The manuscript is well written and the data analysis was well conducted. I advise authors to check the numbering of the references; for example, reference number 63 does not seem to me to be indicated to support the content of the paragraph. Further, the authors should write some parasite and host names in italics (check captions and text).

Author Response

the manuscript “Environmental correlates of prevalence of an intraerythrocytic apicomplexan infecting Caribbean damselfish” deals with a subject that deserves to be published after minor revisions.

 The manuscript is well written and the data analysis was well conducted. I advise authors to check the numbering of the references; for example, reference number 63 does not seem to me to be indicated to support the content of the paragraph. Further, the authors should write some parasite and host names in italics (check captions and text).

 

Thank you. We deleted reference # 63. We checked for missing italics.

Back to TopTop