Improving Keeping for Octopuses by Testing Different Escape-Proof Designs on Tanks for “Big Blue Octopus” (Octopus cyanea)
Round 1
Reviewer 1 Report
This paper deals with the prevention measures of octopus escaping, which occurs often in the aquarium. Prevention method using materials such as filter mat, paper, and shadecloth, which are not able to be adhered by octopus suckers, is very common in the hatcheries working on octopuses (e.g., http://www.fish.wa.gov.au/Documents/research_reports/frr262.pdf, see P67, 118). However, the method demonstrated in this paper may provide useful information for researchers and farmers handling with octopuses. The manuscript is well organized, and I enjoyed reading.
Author Response
Thank you very much for your comments on the manuscript.
We included the suggested report and thank you for your remarks about this manuscript!
Reviewer 2 Report
See attached file.
Comments for author File: 
Comments.pdf
Author Response
Thank you very much for your comments on the manuscript.
We included the suggested report and thank you for your remarks about this manuscript!
We adapted the title of the manuscript following the suggestions of the reviewer.
I would consider using the common name of the species in both the title and manuscript. For the title, a common format is something like, “big blue octopus (Octopus cyanea)”. The abstract should just use common names for both cyanea and vulgaris, with only the first instance in the
text requiring the genus and species followed by the common usage.
- Regarding this comment we included the common name in the title of the manuscript.
Line 12: Consider pluralizing (e.g., ‘have’ and ‘are’), and eliminate “very”.
- We eliminated very and changed to “are”
Line 14 and elsewhere: Extra spaces between sentences. Watch for this throughout manuscript.
- We checked for the extra spaces and similar errors throughout the manuscript
Lines 18-19: It’s not clear what 550l, 600l, or 2000l represents, given that different liters were
described in the methods. I would simply refer to them as 370 L, 360 L, and 3000 L tanks (no
need to state range; there are only 3 tank types). You can also simply say you compared three
different types of tanks (I – III), since other detail are not relevant for the abstract.
- We made this change
Line 20: Avoid the use of ‘enriched dead fish’ here after talking about the environment being
enriched. Otherwise, it sounds like you were giving dead fish enrichment too!
- We removed the word enrichment
Lines 40-41: Eliminate ‘Aquaculture’ at the beginning, otherwise you’re saying ‘aquaculture’
twice.
- Sentence reformulated
Lines 45-51: Seems to be some formatting issues here.
- We checked the manuscript and fixed the formatting issues
Figure 1: C and D seemed to be swapped in the figure description.
- Thank you! We corrected the labeling
Regarding the remark about the statistics we included the numbers for the escapes in Tank 1 A&B. In general we reformulated parts of the results and hope that it is clearer now that the difference between. In total we had 13 cases of es capes of octopuses but only one of these was not from the Tank 1.
Author Response File: 
Author Response.docx
Round 2
Reviewer 2 Report
The authors have adhered to many of the grammatical suggestions I previously made, but the two major concerns have not been addressed: (1) removal of 'welfare' from the title, since this is not a welfare study (no assessment of welfare was addressed), and (2) no inferential statistics were applied to the results.
With respect to the first issue, if the authors are unfamiliar with the vast majority of behavioral and physiological welfare research conducted in farms, zoos, labs, etc., this might be a helpful comparison. The only welfare implication from this study is that minimizing escapes improves survivability, but no direct measure of changes to behavior or physiology are conducted. A more accurate title would be "An evaluation of tank type on escape behaviors for Big Blue Octopus (Octopus cyena)". I will leave the title of the paper to the discretion of the authors, however, the implication of escapes on survivability in octopus is not enough to call this a welfare study.
The second issue is critical to the evaluation of the study, namely, that some type of inferential statistic be applied to the results. As I mentioned before, it's likely that normality and/or homogeneity of variance assumptions are not met, and as such, a nonparametric Kruskal-Wallis ANOVA could be run across the total number of escapes between the 3 tank types. Likewise, a nonparametric Mann-Whitney test (equivalent to a t-test) could be conducted for # of days since an escape between tank 1 and tank 3. Otherwise, you have to provide a clear rationale for why you only used descriptive data to analyze these results. But you have to go one route or the other. Both tests can be conducted using almost any statistical software package, including SPSS (which then needs to be described in the Methods), and shoud be easily implemented.
Otherwise, you've got a nice, clean, and simple study here with obvious implications for protecting octopus in captivity. If you make the title accurately portray that you conducted a study on the ability of octopus to escape their tanks, and then apply some simple statistical tests to the results, you will have a clear demonstration of how tank type can reduce the ability of octopus from escaping their tanks. That itself is worthy of publication.
Author Response
Thank you for your remarks! The answers are in the pdf file and the changes were of course included in the manuscript
Author Response File: Author Response.pdf
Round 3
Reviewer 2 Report
The title change works, and so does the chi-square test. I would additionally show the significant difference in the graph with a symbol or line (also described in the figure caption), and consider applying a similar inferential statistic for days since an escape for Tank 1 to Tank 3.
Author Response
Thank you very much for your comments and suggestions to the manuscript. We added chi2 tests for the number of days animals spent trough out the experimental observation.
Also, we included the statistical information in the figure legend.
Thank you very much again!!!!
Michael
