All reviews of published articles are made public. This includes manuscript files, peer review comments, author rebuttals and revised materials. Note: This was optional for articles submitted before 13 February 2023.
Peer reviewers are encouraged (but not required) to provide their names to the authors when submitting their peer review. If they agree to provide their name, then their personal profile page will reflect a public acknowledgment that they performed a review (even if the article is rejected). If the article is accepted, then reviewers who provided their name will be associated with the article itself.
The authors seem to have satisfied reviewer's criticisms on English usage and on the discussion of the barcode approach at the end of the Introduction, so I agree the manuscript is improved and adequate for publication.
English, and the discussion of the barcode approach at the end of the Introduction, is improved and adequate for publication.
Satisfactory
Good
None
I agree with the comments and suggestions from Rev#1.
Please try to correct as suggested (or formulate a rebuttal if it is the case) and to improve the English language.
I found the results of this study were presented much more clearly than in the original submission, but the English style remains, for me, poor. In fact I find it hard to believe that two ‘professionals’ had separately read the manuscript and all their comments were incorporated – they cannot have been highly proficient in the English language! The title of the paper is now greatly improved, but the wording of the Abstract (for example) remains virtually identical to the original Abstract. It is true that the text can, with a little difficulty, be understood by an English speaker, but in my view it still needs improvement prior to publication.
I continue to recommend editing by a professional English speaker or editing service.
Acceptable
Acceptable
Some specific points:
1. Line 18. ‘30% of fraud in fisheries’ Isn’t this really 30% mislabelling in fisheries? Later in the Abstract the authors mention that not all cases of mislabelling are necessarily fraudulent.
2. Lines 52-58. I did not find the short explanation of DNA barcoding to be useful, and could even be confusing to newcomers to the topic. What is meant by a ‘global system of different mutational rates’? The implication that nucleotides mutate randomly so that 4 * 15 sites would generate 1bn new codes is a considerable simplification of reality – most sites are conserved! Please clarify this paragraph.
3. Line 79. e to and
4. Line 80-82. I couldn’t understand this sentence
5. There are still some spelling errors in scientific names, e.g. for tilapia in Table 1 (but OK in Table 2) and for coho salmon (line 172)
6. Line 115. What is ‘GL’ – is it degrees of freedom?
7. Line 169 autosomal
8. Line 183 what is ‘abastance’?
No further comments to the manuscript.
No further comments to the manuscript.
No further comments to the manuscript.
No further comments to the manuscript.
I do agree with all comments of the reviewers which must be addressed. I highlight the need to introduce the issue of forensic standards and quality control (QC/QA), including a discussion on DNA barcoding based methods and alternatives in forensic context. I also reinforce the request for a deep revision of the English language and to correct the extensive typos. I further think that the allusions to the Cat by Hare Project are best omitted - it is too parochial and to make it understandable to readers in general requires excessively long and irrelevant explanations.
The main issue I had with this paper was its English style. While understandable, it has many errors in grammar and usage. I suggest the authors firstly revise the paper (after considering more specific comments made below) and then get this revised version carefully read and corrected either by a native English speaker or by a professional editing company (there are on-line companies that do this).
The study itself I found to be interesting and satisfactorily carried out, and is within the scope of PeerJ. Raw data, in the form of the barcode sequences, are supplied.
Analytical methods, both the initial barcoding protocols and subsequent assignment of species, were appropriate and generally satisfactorily described.
The results and findings were interesting and adequately referenced. Conclusions were well supported by the data.
1. The major recommendation – apart from improving its English style – is to reconsider and improve the layout of the two Tables. In my view these can be considerably improved by:
a. A: Re-arranging the numbering, so that the correct assignations form Table 1 and the incorrect assignations Table 2. This will obviously then require some small textual changes too.
b. B: Subdividing each Table into two subsections, one being the fishmongers and the other the Japanese restaurants.
c. C: Spell out the names of the genera – as there are many of them, it’s not sufficient to identify them here simply by initial letters.
d. D: Aren’t the numbers in parentheses the best or highest match comparisons, in percent, not the lowest match comparisons?
2. Lines 29-33. Explanation of the Cat by Hare Project is not readily intelligible as given – please clarify.
3. Line 30. Lahiri and Nurnberger, not K. and Nurnberger.
4. Line 89. Blast and BOLD respectively, not BOLD and Blast respectively.
5. Lines 96-103. Please explain the relevance of giving BOLD BIN numbers for these species (or omit them).
6. Line 133-134. Genus not genre.
7. Please check spellings of all scientific names in text and tables. I noticed misspellings of L. niloticus (Table 2) and line 162 O. kisutch. Also give all genus names in full in the text, as you are dealing with a wide variety of genera, not just one or two.
8. Check references. DNA should be given as DNA not as Dna. Line 274 – delete d. Some journals also have part numbers given – e.g. (1) in Barbuto et al. Is this necessary? I suspect these should all be deleted.
The results are described in a way that is not always easy to follow and the language is confusing at some points. An editing by an English native speaker or an editing service is highly recommended.
The introduction should include a brief description of the DNA-based methods used in species identification. It should describe the concept of DNA barcode and its advantages and disadvantages. For example:
L. Wilson-Wilde, J. Norman, J. Robertson, S. Sarre, A. Georges, Current issues in species identi?cation for forensic science and the validity of using the cytochrome oxidase I (COI) gene, Forensic Science, Medicine, and Pathology 6 (2010) 233–241.
The authors should mention in the Introduction section the previous initiatives for the implementation of forensic standards in the identification of species, particularly in the field of food forensics. For example:
F. Teletchea, C. Maudet, C. Hänni, Food and forensic molecular identification: Update and challenges, Trends in Biotechnology 23 (2005) 359–366.
M. Woolfe, S. Primrose, Food forensics: using DNA technology to combate misdescription and fraud, TRENDS in Biotechnology 22 (2004) 222–226.
The methods should be better described.
Which type of material and conditions were implemented for the sample collection? Sterile material? I’m worried about the possible contamination of the samples during the tissue collection. The authors should describe in more detail the sampling process and discuss possible contamination issues. For example, the sample fish piece might have been in contact with pieces from other species, and a cross-contamination is possible.
The sequencing reaction should be briefly explained. Which reaction conditions were used? Which primers? Do the authors sequence the PCR products in both directions?
The parameters used in the Blast and BOLD searches should be indicated (blast algorithm, database, etc). The experiment has to be described in a way that anyone could replicate it.
Lines 92-103. The paragraph is not clear. Why do they used the IUCN Red List of Threatened Species status? Which species are listed here?
Lines 105-108: The English should be revised.
Line 35: parenthesis are missing in the reference
Lines 48-48: the sentence should not be in italics
Line 72: PCR reaction is redundant. The R is for reaction.
Lines 83-85: The sentence should be revised. The meaning is not clear.
Line 172: it should be “species”
The approach used by the author is valid as it has been used by others before.
no comment
All text and materials provided via this peer-review history page are made available under a Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.