Macrotocinclus affinis vs. Otocinclus affinis

[MatsP]

We have Otocinclus affinis, where both CoF and Fishbase have Macrotocinclus affinis. Is there a reason for this (beyond "nobody has updated it")?

Edit: Similarly, CoF and FB has O. arnoldi as a valid species, we have a synonym of O. flexilis.

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Mats

[MatsP]

Bumb!

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Mats

[Jools]

Being one of the infamous DATZ genera, on the first point, it's due to the "wait until it's accepted". Have you seen the name used in the literature beyond DATZ? That said, I think it may be time to change it on the basis that usage will be forthcoming. One look at the wikipedia entry tells you one reason why - this is a long incorrectly identified species.

On the second point, again, I don't know when this was resurrected and in this case would want to understand the specifics of that before resurrecting it here.

Jools

[lfinley58]

Hi,
The below paper uses the genus Otocinclus for affinis. I didn't check FishBase, but Catalog of Fishes does not have this reference included as a source for the topic.

Molecular phylogeny of the Neoplecostominae and Hypoptopomatinae (Siluriformes: Loricariidae) using multiple genes.
Christian Andreas Cramer ⇑, Sandro L. Bonatto, Roberto E. Reis.
Molecular Phylogenetics and Evolution 59 (2011) 43–52.

Maybe this will help a bit.

Lee

[lfinley58]

Hi again,

A follow up to my previous post: The following quote is from Christian Cramer's 2009 PhD thesis (page 85). Of course, such works are not acceptable for taxonomic purposes, but in that Cramer's thesis is, in part, the basis for the above mentioned article, the comment is timely for the discussion herein and explains why the authors consider Macrotocinclus a synonym of Otocinclus.

"Isbrucker and Seidel (in Isbrucker et al. 2001) described the genus Macrotocinclus for the species Otocinclus affinis and O. flexilis, repeating basically Schaefer's definition of the Otocinclus affinis complex (Schaefer 1997). Based on our results (Lehmann 2006; Lehmann et al. submitted; Cramer et al. this volume, this study), Otocinclus is a strongly supported clade and there is no need for a split in two genera. Moreover, the recognition of Macrotocinclus as defined by its authors would turn Otocinclus paraphyletic, as O. xakriaba, O. mimulus, and O. arnoldi are more closely related to O. affinis and O. flexilis than to the remaining species of Otocinclus (Lehmann et al. in press). Therefore, we consider Macrotocinclus as a synonym of Otocinclus."

Lee F.

[Jools]

Thanks Lee, well, that about sinks Macrotocinclus then!

Cheers,

Jools

[Giobemo]

Further discrepancy is Wikipedia giving the common name of "dwarf oto" and stating it is one of the smallest oto species, while PCF gives length as 2", which is larger than almost all of the other common species they list, which all range from 1.3'-1.7", with the exception of flexilis at 2.2".

[Jools]

Yes, you can see that the Wikipedia entry has been half-corrected by someone who knows what is going on but the photo and some of the information is from sources using data originating in the 1950s when

Otocinclus affinis

was incorrectly identified as a common species in the hobby.

Jools