A new Corydoras species (Callichthyidae) from Rio Juruena basin, Brazil

[lfinley58]

FLÁVIO C.T. LIMA & MARCELO R. BRITTO. 2020. A new Corydoras (Ostariophysi: Siluriformes: Callichthyidae) with an unusual sexual dimorphism from the rio Juruena basin, Brazil. Zootaxa, Vol. 4742, No. 3: 518-530.

Abstract:

A new Corydoras is described from the rio Juruena system, upper rio Tapajós drainage, Amazon basin, Brazil. The new Corydoras is distinguished from all congeners by presenting a combination of a conspicuous broad vertical dark bar on head, at the level of the eye (mask), an overall light background color without large blotches or stripes on body or fins, the presence of two to four small dark blotches along the midline, and pectoral spine with antrorse serrations on its posterior margin. Males of the new species possess numerous, well-developed odontodes over the lateral portions of head, pectoral girdle, and pectoral spines, an uncommon feature for the genus. The new species is hypothesized to belong, within the genus Corydoras, either to Lineage 6 or Lineage 9.

The name of the new species is Corydoras rikbaktsa.

https://www.mapress.com/j/zt/article/vi ... a.4742.3.6

[bekateen]

Hi Lee, do you know the name of the species?

Do you have access? If so, may I have a copy please?

Cheers, Eric

[lfinley58]

Hi Eric,
I have only seen the abstract and it (or the title) is sans the new species name. I have a request out for the paper and can follow up when I hear something.

Lee

[bekateen]

Thanks.

Cheers, Eric

[bekateen]

Just found out this is

CW154

.

[bekateen]

The new name for CW154 is Corydoras rikbaktsa (

Corydoras(ln9) rikbaktsa

). The fish is funny looking on its snout. I wouldn't be surprised if it gets reassigned out of lineage 9.

[lfinley58]

Hi Eric,

Thanks for coming up with the species name for this newest species of Corydoras. I have added the name to my original post on the paper.

Lee

[catmandave]

Eric,
First time that I've seen parenthesis inserted between the generic and species name.
Is this accepted by the scientific community ?

[Dave Rinaldo]

Eric,
First time that I've seen parenthesis inserted between the generic and species name.
Is this accepted by the scientific community ?

It is preparation for 'splitting' Corydoras.

viewtopic.php?f=6&t=48760
viewtopic.php?f=1&t=48006&p=318820&hili ... es#p318820

[CatfishFiend]

AFAIK, the parentheses wouldn't be seen in a published article, but I'm all for differentiating organisms in ways which feel more useful to specific communities

[Karsten S.]

Hi,

the authors already stated that this species has features that don't really fit into the lineages, the snout is rather too long for lineages 6 & 9, their conclusion was that this feature would be rather typical for lineage 8.
The tentative assignment to lineages 6 or 9 was based on pectoral spine serration and infraorbital 1 & 2 shapes. I cannot really judge the taxonomical value of this feature but among (real) Aspidoras species there is a remarkable variance in the shape of the infraorbitals, I can very well remember the very interesting presentation of Luiz on the Coryvention.

I agree that the pectoral spine serration is not at all fitting to lineage 8 and this is IMHO the most solid feature together with snout shape.
The species from lineage 6 for which I have picture of pectoral spine serration show a much weaker serration and all have a short snout, this would be very surprising if C. rikbaktsa would end up there.
For species from lineage 9 the situation is very similar to lineage 6, serration is short and snout is short, I would be equally surprised if this should be a member of this lineage.
I'm really surprised why they have not even considered lineage 1.

IMHO the snout shape falls within the range of lineage 1, the pectoral spine serration is long (saw-like) as for most of lineage 1 species. Another feature they have not discussed is the position of the eye which is for me another evidence that points rather to lineage 1 (rather than 6 or 9), it is in a quite high position of the head which is quite useful considering that those species often search for food hidden deep in the sand.

I wouldn't be surprised if it gets reassigned out of lineage 9.

Who has assigned this to lineage 9 (the authors did not):

...cannot be presently assigned to any of the corydoradine lineages proposed by Alexandrou et al. (2011).

They just speculated...

...most of its morphological features indicating it to putatively belong either to lineage 6 or lineage 9

.

...whatever "most features" means .

Cheers,

[bekateen]

I wouldn't be surprised if it gets reassigned out of lineage 9.

Who has assigned this to lineage 9 (the authors did not):

Hi Karsten,
I believe CW154 was originally listed as lineage 9 on the CW page. Now it is no longer listed in a single lineage.

Cheers, Eric