The Dancing Marsenia: The First Record of a Swimming Velutinid Mollusc

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript provides a detailed and fascinating description of an adult velutinid gastropod swimming in the water column. The authors have also provided a video of the animal performing the act. The specimen has also been tentatively identified based on the CO1 gene sequence. I have no major criticisms. However, I found it difficult to relate the description of the animal in the text to the images provided in Figure 1. For instance, which part of the foot shown in Fig. 1A and B forms the ‘paddle’ as seen in Fig. 1C through Y? May I suggest that the authors identify the parts of the animal that are referred to in the text on the relevant images in Figure 1 to help the reader in visualising the act of swimming by the gastropod. In connection with this, a brief morphological description of the animal is not out of place in the Results section. 

 

There is no animal in the last 4-5 seconds of the video clip which can be deleted to reduce file size.

 

The text would benefit from language editing. I have tried to correct the English used though it is not exhaustive.

 

Additional comments and suggestions are provided directly on the pdf attached.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor editing required.

Author Response

Thank you for your comments. The figure was updated following suggestions and in the result section we added an anatomical description of the snail (with reference to the figure). The video was edited, cutting the end. The text was further edited following suggestion included in the pdf. Regarding the possibility that this behaviour was elicited by divers’ flashes, it is hard to make an hypothesis, also considering that, when it was first spotted, the snail was already swimming (we added this to the manuscript as well). The manuscript was revised by an English speaking colleague that improved the form.

Reviewer 2 Report

Comments and Suggestions for Authors

A nice short report, some minor corrections seem necessary, please see my comments on your file

Comments for author File: Comments.pdf

Comments on the Quality of English Language

in general moderately good, at some places either hard to understand or clear, but out of grammatic rules,

Author Response

Thank you for your comments, we edited the text accordingly to your notes in the pdf. For calculating genetic distance, K2P model was used, to be consistent with what used so far for velutinids and to be able to compare values in the future (this was added in the text as well). The manuscript was reviewed by an English speaking colleague that improve the form.