Review Reports - <i>Maylandia</i> (Teleostei: Cichlidae) Remains a <i>Nomen Nudum</i>

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript addresses a long-standing taxonomic controversy regarding the validity of the generic name Maylandia versus Metriaclima for a group of rock-dwelling cichlids endemic to Lake Malawi. This is a relevant and persistent issue in African cichlid taxonomy, and the authors provide a historical and nomenclatural argument in support of treating Maylandia as a nomen nudum.

Unfortunately, I was not able to review all the previous literature cited in detail. However, based on the content presented, it is clear that the central issue preventing a conclusive resolution remains the lack of robust diagnostic characters to support either taxon. Without a proper diagnosis—including direct comparisons with the holotype of Pseudotropheus williamsi and a more in-depth anatomical study (e.g., complete osteology)—any taxonomic proposal will remain speculative and largely based on personal interpretation.

Major Concerns and Recommendations:

Need for empirical support: I strongly recommend that the authors incorporate a scientific test of the hypothesis they are defending. A grouping analysis that includes all relevant taxa would provide a more objective foundation for their taxonomic conclusions. A straightforward molecular approach using the COI marker could help determine whether the resulting clades support the recognition of Maylandia or Metriaclima as valid genera. This would elevate the manuscript from a historical commentary to a hypothesis-driven contribution.
Alternative path via ICZN: If the authors are not inclined to pursue additional empirical analyses, I suggest submitting this case to the International Commission on Zoological Nomenclature (ICZN). A formal ruling by the Commission would provide a definitive resolution to this nomenclatural dispute and would be more appropriate for the nature of the argument presented.
Manuscript formatting and taxonomic standards: The manuscript would benefit from a more polished and rigorous presentation. For instance, the first mention of any genus or species name must be accompanied by the author and year of publication, as required by the conventions of zoological nomenclature. This level of precision is expected in taxonomic manuscripts and should be addressed throughout the text.

Conclusion:

In its current form, I do not recommend the manuscript for publication. However, I believe it could make a valuable contribution to the field if revised substantially. I encourage the authors to consider either strengthening the manuscript with empirical data or pursuing formal adjudication through the ICZN. Additionally, attention to nomenclatural formatting and editorial refinement is essential.

Author Response

Need for empirical support: I strongly recommend that the authors incorporate a scientific test of the hypothesis they are defending. A grouping analysis that includes all relevant taxa would provide a more objective foundation for their taxonomic conclusions. A straightforward molecular approach using the COI marker could help determine whether the resulting clades support the recognition of Maylandia or Metriaclima as valid genera. This would elevate the manuscript from a historical commentary to a hypothesis-driven contribution.
We are not certain what the reviewer means. Our sole argument is nomenclatural in that the nomen Maylandia is unavailable because it wasn’t described in compliance with the requirements of the Code, i.e. Article 13.1.1. We do not hypothesize any taxonomic statement or argue whether either Maylandia or Metriaclima would better represent a monophyletic clade in a molecular analysis.
Alternative path via ICZN: If the authors are not inclined to pursue additional empirical analyses, I suggest submitting this case to the International Commission on Zoological Nomenclature (ICZN). A formal ruling by the Commission would provide a definitive resolution to this nomenclatural dispute and would be more appropriate for the nature of the argument presented. More than 20 years ago we have tried to get a ruling by the Commission but they declined to take the case because it is a not a matter where the rules of the Code need to be overridden. We were fine with that decision as we were able to describe new species using the correct name Metriaclima. Only recently, Scharpf (2025) bullied editors and reviewers into refusing that name and adopting Maylandia which he deemed valid.
Manuscript formatting and taxonomic standards: The manuscript would benefit from a more polished and rigorous presentation. For instance, the first mention of any genus or species name must be accompanied by the author and year of publication, as required by the conventions of zoological nomenclature. This level of precision is expected in taxonomic manuscripts and should be addressed throughout the text. We have adjusted the manuscript conformingly.

Reviewer 2 Report

Comments and Suggestions for Authors

Please find below my detailed comments regarding the text itself.

Abstract:

Page 1, Line 15: I would ask the authors to add a refer to the ICZN of the year 1963 as the current code (ICZN, 2000; see: The provisions of this Code supersede those of the previous editions with effect from 1 January 2000 (ref: https://www.iczn.org/the-code/the-code-online/), does not have an “Article 13a”. As such, the reader is lost with the info as given in the abstract at present. I would further make it clear to what part of Article 13 it currently corresponds, which is Article 13.1 if I am right.

Line 15-17. For me, the fact that “more than 30 species” where described in the other genus, i.e. Metriaclima, than the one which is considered valid, at present, does not provide evidence for the correctness of the proposition made by the authors. The same holds true for the next sentence (lines 17-18). I would also make visible in the manuscript that the last author, sometimes together with the first author of the present manuscript, where the ones who described those species. This will help to better contextualize the entire issue.

Introduction:

Lines 30-31: As this is a taxonomic paper, I would like to suggest using full taxonomic names (e.g. for genus and species names) when mentioned the first time: e.g. Melanochromis Trewavas 1935 instead of just “... Melanochromis Trewavas ...”. Further, I think it would be good to provide the full reference of these papers, in this case Trewavas, E. 1935: A synopsis of the cichlid fishes of Lake Nyasa. Annals and Magazine of Natural History (Series 10) v. 16 (no. 91) (art. 6): 65-118. The same holds true for “ ... Pseudotropheus Regan ... ”.

Line 37-38: I would reformulate the sentence, “… with the Pseudotropheus zebra species complex containing 27 species and …” … and idem for the other species complex.

Line 40: “type species”, no?

Line 42: “nomen nudum ». See current code for a definition (ICZN, 2000 : glossary) « nomen nudum (pl. nomina nuda), n.

A Latin term referring to a name that, if published before 1931, fails to conform to Article 12; or, if published after 1930, fails to conform to Article 13. A nomen nudum is not an available name, and therefore the same name may be made available later for the same or a different concept; in such a case it would take authorship and date [Arts. 50, 21] from that act of establishment, not from any earlier publication as a nomen nudum.”

I would see if it would not be good to provide this definition of the use of “nomen nudum” somewhere also, as it specifically refers to Article 13.

Page 2, Line 43: The fact that a genus name has not been used for a long time does not in itself be a statement regarding its validity or not.

Lines 49-50: Indeed, I can agree that Scharpf was too strong in his decision that all papers presenting another argument should be refused. However, if this debate does not seem to settle, it may be worthwhile considering submitting a petition to the ICZN to settle it once and for all.

Materials and Methods

Page 3, Lines 57-58: As mentioned before, I would explicitly refer to the actual Article of the code which corresponds to Article 13a of the ICZN (1964) version.

Page 3, Line 60-62: I am pleased to read that indeed the authors differentiate between what the author(s) of a paper state and the reality of their statements, where a statement does not need to be correct to result in the validity of a species name.

Results

Lines 91-92: OK, and what is the problem with this observation? I cannot follow why this is of critical importance.

Line 104- page 4, Line 105: The authors are using double quotation marks “***” to cite text as given in some published papers (see also lines 108-109). However, the source, i.e. reference, of these quotation marks is not provided. Therefore, I would like to ask the authors of the present paper to clearly provide those, also for the IUCN and add reference to the cited pages as well. That will be helpful to all readers who want to verify some info for themselves.

Discussion

Page 4, Lines 147-149: I would be prudent regarding the statement on Eschmeyer “Catalog of fishes” choice, as I am not sure Eschmeyer et al. (2025) made an explicit choice on what reference to follow. Often, they just refer to the latest publication to avoid having to make this kind of evaluation themselves, even if the last author(s) cited is/are not always well informed about the status of a certain species. That is my understanding of it, even if, although I looked for it, I have, unfortunately, no direct example to provide for my interpretation.

Lines 150-152: As stated above already, the fact that something has been done differently for a long lapse of time is, in itself, not an argument to the correctness of what has been done in the past. Therefore, I would suggest avoiding this kind of statement as it cannot be part of the argumentation. Further, the “30 species” are described by the some of the authors themselves, which, as such, explains the reason for this, apparent, contradiction.

Author Response

>We agree that the statement has no bearing on the validity of a name and have removed both sentences.

>We corrected and added the reference to each entry.

Line 37-38: I would reformulate the sentence, “… with the Pseudotropheus zebra species complex containing 27 species and …” … and idem for the other species complex.

>The sentence has been reformulated. Thank you.

5—Line 40: “type species”, no?

>We have added “species” so there is no ambiguity.

Line 42: “nomen nudum ». See current code for a definition (ICZN, 2000 : glossary) « nomen nudum (pl. nomina nuda), n.

I would see if it would not be good to provide this definition of the use of “nomen nudum” somewhere also, as it specifically refers to Article 13.

>We have now added the Code’s definition of a nomen nudum earlier in the introduction and added its reference.

Page 2, Line 43: The fact that a genus name has not been used for a long time does not in itself be a statement regarding its validity or not.

>We agree completely and we don’t use it as an argument. We were just surprised at the time by the sudden animosity defending a name that hadn’t been in use at all.

>As mentioned above, we sought confirmation with the Commission but they declined because it wasn’t a case where the Code’s rules needed to be overridden.

Page 3, Lines 57-58: As mentioned before, I would explicitly refer to the actual Article of the code which corresponds to Article 13a of the ICZN (1964) version.

>We have done so. Thank you for the precision.

10—Page 3, Line 60-62: I am pleased to read that indeed the authors differentiate between what the author(s) of a paper state and the reality of their statements, where a statement does not need to be correct to result in the validity of a species name.

11—Lines 91-92: OK, and what is the problem with this observation? I cannot follow why this is of critical importance.

(This refers to the sentence: “This indicates that this complex forms only part of the proposed subgenus and furthermore that the authors did not regard their subgenus as being monotypic.”)

>We have now added “…which could have validated their description by adopting the differentiating characters of the type species.” The reason we mention this is the fact that later on, Condé & Géry (1999) tried to “salvage” the name Maylandia by claiming that it was meant as a monotypic genus in which case it would adopt the diagnosis of the type species.

12—Line 104- page 4, Line 105: The authors are using double quotation marks “***” to cite text as given in some published papers (see also lines 108-109). However, the source, i.e. reference, of these quotation marks is not provided. Therefore, I would like to ask the authors of the present paper to clearly provide those, also for the IUCN and add reference to the cited pages as well. That will be helpful to all readers who want to verify some info for themselves.

>We have added the page reference and quoted the full text pertaining to the argument.

13—Page 4, Lines 147-149: I would be prudent regarding the statement on Eschmeyer “Catalog of fishes” choice, as I am not sure Eschmeyer et al. (2025) made an explicit choice on what reference to follow. Often, they just refer to the latest publication to avoid having to make this kind of evaluation themselves, even if the last author(s) cited is/are not always well informed about the status of a certain species. That is my understanding of it, even if, although I looked for it, I have, unfortunately, no direct example to provide for my interpretation.

> In order to make clear that Eschmeyer’s list is not an impartial compilation of names we have added “… because it did not accept Stauffer et al.’s conclusion to declare Maylandia a nomen nudum in 1997.” The Catalog of Fishes never listed Metriaclima as valid which they would have if they would refer to the latest publication. The list is also not infallible. Eschmeyer’s list made a personal change in a scientific name: Lobochilotes labiatus. They list it as Lobochilotes labiata and claim that Lobochilotes is feminine which is incorrect as it is masculine. The author of Lobochilotes Boulenger 1915 treats it as masculine because he gives Lobochilotes labiatus as its type species. In another instance the Catalog of Fishes lists Pseudohaplochromis Allgayer 1981 as a valid genus name for Haplochromis euchilus Trewavas 1935, but then makes the following statement: “Senior synonym of Cheilochromis Eccles & Trewavas 1989; but prevailing usage prefers Cheilochromis”. Pseudohaplochromis was never meant as a description and certainly doesn’t comply with the Code, and there never was a ruling from the ICZN Commission to use Cheilochromis instead. We give these examples to indicate that even though the Catalog of Fishes is very useful for researchers to check on the status of certain species, we think it is not “the law” in fish nomenclature.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed the comments and suggestions raised in the previous review. The requested modifications have been incorporated into the revised manuscript.

Based on the current version, the manuscript is considered suitable for publication.