The Symbiotic Relationship between the Antarctic Limpet, Nacella concinna, and Epibiont Coralline Algae
Round 1
Reviewer 1 Report
Review
Paper title: The symbiotic relationship between the Antarctic limpet, Nacella concinna, and epibiont coralline algae
The authors conducted a comparative study to reveal the significance of epibiont coralline algae for their host, the Antarctic limpet, Nacella concinna. After rearing under laboratory conditions the authors measured the mortality rate, weight, condition factor, fatty acid content, and structure of the shell surface in limpets colonized by coralline algae and free of these symbionts. The authors found that on one hand the symbiont led to an increase in mortality and shell weight (negative effects) but on the other hand Nacella concinna protected the shell surface against damages (positive effect). This study provides an interesting example of a symbiotic association that may be classified as parasitism or mutualism depending on environmental conditions.
All these reasons explain the relevance of the paper by Boongho Cho and co-authors submitted to "Journal of Marine Science and Engineering".
General scores.
The data presented by the authors are original and significant. The study is correctly designed. In general, the statistical analyses are performed with good technical standards. We authors conducted careful work which will attract the attention of a wide range of specialists focused on symbiotic relationships in the marine environment.
Recommendations.
L 63. The authors should clarify the sampling method (by hand, by SCUBA diving?) and depth.
L 63-64, 71-73 The authors should indicate the period(s) of sampling.
Figure 1. The authors should increase the font and resolution of the sidebar.
L 216-218. The authors should provide references for this statement.
L 245-254. This section should be formatted as "Conclusion".
Specific comments.
L 116. Change “samples” to “samples were”
L 144. Change “10%” to “50%”
L 144. Change “compared with” to “compared to”
L 145. Change “50%” to “10%”
L 190. Change “examines” to “examining”
L 200. Change “algae acts” to “algae act”
L 200. Change “with its” to “with their”
L 210. Change “Fatty acid composition” to “The fatty acid composition”
L 211. Change “was significantly different” to “was found to vary significantly”
L 215. Change “fatty acid composition” to “the fatty acid composition”
L 222. Change “mechanism” to “functioning”
Author Response
Recommendations.
L 63. The authors should clarify the sampling method (by hand, by SCUBA diving?) and depth.
L 66. Sampling was done by hand.
L 63-64, 71-73 The authors should indicate the period(s) of sampling.
L 65-66, L 75. Modification completed.
Figure 1. The authors should increase the font and resolution of the sidebar.
L 80. Modification completed.
L 216-218. The authors should provide references for this statement.
L 211. Modification completed.
L 245-254. This section should be formatted as "Conclusion".
L 238. Modification completed.
Specific comments.
L 116. Change “samples” to “samples were”
L 116. Modification completed.
L 144. Change “10%” to “50%”
L 142. Modification completed.
L 144. Change “compared with” to “compared to”
L 142. Modification completed.
L 145. Change “50%” to “10%”
L 143. Modification completed.
L 190. Change “examines” to “examining”
L 186. We think the expression we used before is more appropriate.
L 200. Change “algae acts” to “algae act”
L 195. Modification completed.
L 200. Change “with its” to “with their”
L 196. Modification completed.
L 210. Change “Fatty acid composition” to “The fatty acid composition”
L 204. Modification completed.
L 211. Change “was significantly different” to “was found to vary significantly”
L 205. Modification completed.
L 215. Change “fatty acid composition” to “the fatty acid composition”
L 209. Modification completed.
L 222. Change “mechanism” to “functioning”
L 216. Modification completed.
Reviewer 2 Report
The authors completed an interesting study on the relationship between Antarctic limpet and epibiont coralline algae. This manuscript is prepared well with detailed methodology. I didn't find any technical errors in the manuscript.
Author Response
Thank you for reviewing the manuscript.
Reviewer 3 Report
Keywords: should be Antarctica (capital letter) – is Earth’s southernmost continent
Introduction
The introduction briefly summarizes knowledge about epibiosis phenomenon and Antarctic limpet Nacella concinna . However, there is nothing mentioned about the ecology and morphology of main epibiont coralline algae Clathromorphum obtectulum.
The coralline red algae (Rhodophyta, Corallinales) are widespread in all of the world’s oceans, where they often cover close to 100% of rocky substrata. These algae are one of the abundant seaweed groups and represent a principal component of the marine ecosystems. Clathromorphum obtectulum is very common in intertidal pools and in the subtidal along the Antarctic Peninsula. It often grows on the shells of limpets. The crust reaches 1.3 cm in thickness (Mendoza & Cabioch 1985) and has a relatively smooth surface. Conceptacles are embedded in the thallus, so it can be difficult to determine that the tetrasporangial conceptacles are multiporate.
Please introduce (Introduction) more information about habitat, distribution, biology and ecology of study species. Do the Authors have photographic documentation of C obtectulum?
Materials and methods
I am positively surprised by the very detailed description of the methods used.
References
The following publications should be included in manuscript and References: 1) Schoenrock et al. 2015. Climate change confers a potential advantage to fleshy Antarctic crustose macroalgae over calcified species. Journal of Experimental Marine Biology and Ecology, 474:58-66; 2) Wiencke Christian (Ed.) 2011. Biology of Polar Benthic Algae. In the series Marine and Freshwater Botany.
Comments for author File: 
Comments.pdf
Author Response
The introduction briefly summarizes knowledge about epibiosis phenomenon and Antarctic limpet Nacella concinna . However, there is nothing mentioned about the ecology and morphology of main epibiont coralline algae Clathromorphum obtectulum.
The coralline red algae (Rhodophyta, Corallinales) are widespread in all of the world’s oceans, where they often cover close to 100% of rocky substrata. These algae are one of the abundant seaweed groups and represent a principal component of the marine ecosystems. Clathromorphum obtectulum is very common in intertidal pools and in the subtidal along the Antarctic Peninsula. It often grows on the shells of limpets. The crust reaches 1.3 cm in thickness (Mendoza & Cabioch 1985) and has a relatively smooth surface. Conceptacles are embedded in the thallus, so it can be difficult to determine that the tetrasporangial conceptacles are multiporate.
Please introduce (Introduction) more information about habitat, distribution, biology and ecology of study species. Do the Authors have photographic documentation of C obtectulum?
L 48. We added information about coralline algae (C. obtectulum). The photographic of C. obtectulum is presented in Figure 2a.
References
The following publications should be included in manuscript and References: 1) Schoenrock et al. 2015. Climate change confers a potential advantage to fleshy Antarctic crustose macroalgae over calcified species. Journal of Experimental Marine Biology and Ecology, 474:58-66; 2) Wiencke Christian (Ed.) 2011. Biology of Polar Benthic Algae. In the series Marine and Freshwater Botany.
L 50, 52. We included references that you suggest.
Reviewer 4 Report
Manuscript titled "The symbiotic relationship between the Antarctic limpet, Nacella concinna, and epibiont coralline algae" by Cho et al. aims a study of the effects of the coralline algae in the physical condition (mortality, weight, condition factor, fatty acid content) and morphology of the shell surface of the limpets.
The results shown that the presence of coralline algae significantly increased the mortality of the limpets and altered the fatty acid profiles related to the limpet’s lipid metabolism.
The manuscript is an interesting paper and it provides undoubtedly new data that make an important contribution to the knowledge in this field.
Approach, methodologies and analysis used in this work can be considered satisfactory. Language is clear and understandable. Results are clearly presented and sufficiently discussed. Its content in general justifies the length of manuscript. Language is clear and understandable. Figure are of good quality.
In general, this work is a good reference for other researchers and I recommend its publication
However, I suggest some advices that could improve the manuscript.
Although the authors state the total number of individuals collected, it is not clear how many samples were included in each analysis.
For instance, in table 1, the fatty acid composition of groups was analyzed in 20 samples with presence and 20 with absence of coralline algae. Was it a number chosen for analytical statistical convenience or was it a consequence due to the mortality of the individuals? And in the SEM analysis of external damage, how many samples were used? In my opinion, these topics should be better explained and the data added to each paragraph.
In the References, L272 I think that the complete citation is:
Wahl, M. Epibiosis: Ecology, Effects and Defenses. In: Marine Hard Bottom Communities: patterns, dynamics, diversity, and change, ed. by Wahl, Martin. Springer Series: Ecological Studies, 206 . Springer, Heidelberg, pp. 61-72. ISBN 978-3-540-92703-7
but it needs to be formatted following the journal guidelines. Please, fix that.
Author Response
Although the authors state the total number of individuals collected, it is not clear how many samples were included in each analysis.
For instance, in table 1, the fatty acid composition of groups was analyzed in 20 samples with presence and 20 with absence of coralline algae. Was it a number chosen for analytical statistical convenience or was it a consequence due to the mortality of the individuals? And in the SEM analysis of external damage, how many samples were used? In my opinion, these topics should be better explained and the data added to each paragraph.
L 72, 110, 127. We added information about the number of samples used.
The 20-sample number was chosen for analytical statistical convenience and due to limitations in culture conditions.
McClintock et al. [19] reported that coralline algae attached to limpet shells have a protective role from external stress. Therefore, to confirm the results of the preceding research again, SEM analysis was performed using only one specimen, and similar results were obtained.
In the References, L272 I think that the complete citation is:
Wahl, M. Epibiosis: Ecology, Effects and Defenses. In: Marine Hard Bottom Communities: patterns, dynamics, diversity, and change, ed. by Wahl, Martin. Springer Series: Ecological Studies, 206 . Springer, Heidelberg, pp. 61-72. ISBN 978-3-540-92703-7
but it needs to be formatted following the journal guidelines. Please, fix that.
L 267. Modifications completed.
