New cory: Corydoras costai

[bekateen]

Ottoni, F. P., Barbosa, M. A. & Katz, A. M. 2016. A new Corydoras from floodplain swamps of the São Francisco river basin, northeastern Brazil (Siluriformes, Callichthyidae). Spixiana 39 (1): 131-140.

ABSTRACT
Corydoras costai is a new species described from seasonal swamps adjacent to the upper Rãs river of the Caatinga, tributary of the São Francisco river basin, northeastern Brazil. The new species, as well as C. difluviatilis, differ from all other Corydoradinae by having parapophyses of fourth free vertebra reduced and separated from each other, not fused into a haemal arch. Corydoras costai shares a unique colour pattern with C. garbei and C. difluviatilis, differing from both C. garbei and C. difluviatilis by having fewer rib pairs; from C. garbei by having odontodes present on infraorbitals and opercle, and nuchal plate not in contact with supraoccipital plate; and differing from C. difluviatilis by having five well delimited large dark brown blotches from the caudal fin base to the posterior margin of opercle, along the junction of dorsal and ventral plates on the midline of body, lower region of cleithrum dark brown, first haemal arch present on sixth free vertebra, fewer precaudal vertebra, fewer not segmented rays on anal fin, a shorter head and a deeper head. The new species shares with Corydoras difluviatilis the lack of contact between the supraoccipital and nuchal plate, small degree of ossification of the second hypobranchial and large mesial expansions on the first and second infraorbitals; which suggest a basal position within the Corydoradinae. The serrations on posterior margin of pectoral­-fin spine revealed to be a polymorphic character in C. costai.

[bekateen]

I've been told that there may be some question as to the legitimacy of this description. The specimens used to characterize this species may be a mix of

Corydoras garbei

and

Corydoras difluviatilis

.

[Jools]

In such cases, we tend to add the new species (it's a fact) but also the concerns in ID or general parameters. On a skim read, the paper does seem to examine those species you mention and provide differences. However, I don't know how good there are as characteristics.

If it gets sunk, then the catelog admin provides for merging data (although these are not likely to be kept), adding a synonym and renaming the junior synonym entry.

Jools

[bekateen]

Okay thanks. I've set up the new CLOG page. I'll email you later with details of the concern.

Cheers, Eric

[Horlack]

I've been told that there may be some question as to the legitimacy of this description. The specimens used to characterize this species may be a mix of

Corydoras garbei

and

Corydoras difluviatilis

.

Even if it is declared as a new species, so I object.
The corydoras can travel long distances, and even if their habitat is destroyed.
Too many corydoras , are found in this area as the

Corydoras difluviatilis

or

Corydoras garbei

.
A lot of corydoras can hybridize.

It is amazing to see, at least questioning , because this is an area inhabited for some time that sustained high ecological pressure.
And one discovers that now ?

I dont say that the description is wrong, I say, no comparative DNA analysis = doubt = hybrid possible ?
For me, without DNA analysis, it is not a new cory. Its is only a description of a cory.

=====================
example : American wolf
French Source : http://www.sciencesetavenir.fr/animaux/ ... seule.html

English traduction : https://translate.google.com/translate? ... edit-text=

Original paper : http://advances.sciencemag.org/content/2/7/e1501714

There are not three wolf species in North America but only one [coywolf (Canis lycaon), gray wolf (Canis lupus), red wolf (Canis rufus)]

When the habitat of an animal species suffered enormous stress, so to survive, she is forced to breed with other species. As the Coyote.
Old :
coywolf (Canis lycaon) = 75% DNA gray wolf (Canis lupus) + 25% Coyote (Canis latrans)
red wolf (Canis rufus) = 25% DNA gray wolf (Canis lupus) + 75% Coyote (Canis latrans)

There maybe 250.000 Canis lycaon in Ontario + USA, the number of population does not prove that it is a species. It is 250.000 hybrids.

In fact, there are only one wolf specie : Canis lupus
The 2 other are hybrids.

[bekateen]

I agree that genetic sampling seems necessary to confirm anything in this case. Otherwise, it may be a mess, whether because it is a hybrid or simply because it was characterized using a mix of atypical individuals which are variations within one species (Corydoras garbei) or the other (Corydoras difluviatilis).

Cheers, Eric