Timing of Increment Formation in Atlantic Bluefin Tuna (Thunnus thynnus) Otoliths

Round 1

Reviewer 1 Report

 

The manuscript is interesting methodologically, however it has some weaknesses.

 In the introduction they must explain what hypotheses they test at paper and what is the problem they want to solve. The presence of the bimodal model occurs in other species?

The authors should explain this and the biological meaning of bimodality in the discussion section.

In the discussion (L340-352) it should be clarified what specifically is the proposal of the authors in the adjustment of the criterion.

In the discussion, the authors should compare their results with those of other similar works and also explore the biological implications of their results in the life of the species.

Authors should include a conclusions section in their paper.

Minor suggestions:

The authors should check that the name of the species is in italic (line 27)

Figure 1. It is not clear, it does not possess an adequate quality for a publication.

 Figure 5 In the legend of the figure should be explained the abbreviations AIMP, Al1 Al2

Figure 6. In the legend of the figure should be explained the abbreviations of the edge (O, WT, NT)

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This paper observes and analyzes a large number of otoliths and estimates the timing of formation of the translucent and opaque zones, and I think it has high scientific value. The analysis method sounds also valid. Also, I think that the discussion showing actual method of age determination is more suitable for the manual for ICATT, but I recognize that this description can be applied to other fish species.

 

I have no objection to the conclusion.

Below are my interpretations and comments. Please consider it.

 

I think the NT in Table 2a is as follows.

N-1 (Dec-May), N (June-July), N (Aug-Nov)

 

Discussion The content is complicated, so if possible, write a simpler description.

 

353-369 After all, does it mean that a translucent zone is formed at high water temperatures? The possibility cannot be denied, but I interpret it as the opaque zone is formed from before the spawning season to the spawning season, and the discontinuous structure of the otolith crystals is observed as a bundle and brownish (See Katayama, 2018, https://doi.org/10.1007/s12562-018-1228-z).

 

373-391 It is general sense that the ageing character method of an individual is far more accurate than the body length composition method and the ALK method, and if it is described, I think that Introduction is more suitable than Discussion.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The suggestions were incorporated by the authors.