Hypostomus velhomonge, new species... is it L078?

[bekateen]

Lustosa-Costa, S. Y., Ramos, T. P. A., Zawadzki, C. H., & Lima, S. M. Q. (2022). Review of the armoured catfish genus Hypostomus (Siluriformes: Loricariidae) from the Parnaíba River basin, Northeastern Brazil, with description of a new species. Neotropical Ichthyology, 20.

Hypostomus velhomonge

, new species

Is this new species (or is the Hypostomus aff. pusarum described herein) an identity for

L078

?

And oddly, I don't see any Hypostomus in this paper fitting close to

L077

, which bears at least a passing resemblance in its color pattern to

Hypostomus faveolus

... peculiar they didn't report anything like this.

https://doi.org/10.1590/1982-0224-2021-0126
https://www.scielo.br/j/ni/a/8QdZZxdjvM ... z/?lang=en

Abstract
The species of

Hypostomus

from the Parnaíba River basin were reviewed through molecular and morphological analysis. Five species were found in the basin, including a new species herein described. The distribution of H. pusarum was expanded to this basin, and a closely related species was recorded (H. aff. pusarum), also the presence of H. johnii and H. vaillanti was confirmed. The new species is distinguished from most congeners by its large number of premaxillary and dentary teeth, a wide dental angle of 115° to 135°, presence of a rounded dark spots on a lighter background and anteromedial region of the abdomen depleted of plaques (vs. anteromedial region of the abdomen covered by platelets and odontodes in H. johnii, H. pusarum, H. aff. pusarum and H. vaillanti). Furthermore, an identification key of the species from the Maranhão-Piauí ecoregion and maps with the geographic distribution of these species are presented. The species of Hypostomus in the Parnaíba River basin have different geographic distributions, suggesting different niches or geographical barriers, providing an opportunity for ecological and evolutionary studies.

Keywords: Cryptic diversity; DNA Barcode; Identification key; Integrative taxonomy; Maranhão-Piauí ecoregion

[Jools]

Pretty sure L078 is one of the species mentioned in the paper, but can't see the plates. Given smaller than eye sized spots on the head, is the longer lower caudal lobe the key feature to makes L078 = this new species?

Jools

[bekateen]

Pretty sure L078 is one of the species mentioned in the paper, but can't see the plates. Given smaller than eye sized spots on the head, is the longer lower caudal lobe the key feature to makes L078 = this new species?

Jools

Email sent.

Also, I didn't add Hypostomus velhomonge to the CLOG yet, waiting to find out if I'm just renaming an L number or creating a new entry.

[Jools]

Good call and thanks for sending. Sorry, I meant plates in terms of the armour plates on the fish as mentioned in the key. L078 is something of a phantom in the hobby, but going on what we know, I would be inclined to make L078 = Hypostomus velhomonge. Interested in others views / check my assumptions.

Jools

[bekateen]

Sorry, I meant plates in terms of the armour plates on the fish as mentioned in the key. L078 is something of a phantom in the hobby, but going on what we know, I would be inclined to make L078 = Hypostomus velhomonge. Interested in others views / check my assumptions.

Jools

@Acanthicus ?

[Acanthicus]

Hi,

I think L 78 is the fish mentioned as H. aff. pusarum (fig.10) in the paper. The eye size of H. aff. pusarum matches L 78 better than H. velhomonge does. Plus, in DATZ Rainer mentioned the elongated caudal lobes, which are also present in the specimen of H. aff. pusarum. Obviously they might be broken in the specimen shown as H. velhomonge, but to me the fin doesn't look like it should have elongated caudal lobes.

The whole body of H. velhomonge seems more compressed than what I imagine L 78 would look like on comparable pictures. The mouth is very wide, larger than in H. aff. pusarum. Based on the one specimen presented by DATZ my feeling is that L 78 doesn't have such a large oral disk.

About the missing L 77: I wondered too at first, but read the DATZ presentation again and there is no accurate locality given for L 77. it was just imported with some Geophagus sp. from the Parnaiba area, but who knows where exactly it was collected. Maybe it was not within the "Maranhão-Piauí ecoregion", which the paper is about.

[bekateen]

Hi,

I think L 78 is the fish mentioned as H. aff. pusarum (fig.10) in the paper. The eye size of H. aff. pusarum matches L 78 better than H. velhomonge does. Plus, in DATZ Rainer mentioned the elongated caudal lobes, which are also present in the specimen of H. aff. pusarum. Obviously they might be broken in the specimen shown as H. velhomonge, but to me the fin doesn't look like it should have elongated caudal lobes.

The whole body of H. velhomonge seems more compressed than what I imagine L 78 would look like on comparable pictures. The mouth is very wide, larger than in H. aff. pusarum. Based on the one specimen presented by DATZ my feeling is that L 78 doesn't have such a large oral disk.

About the missing L 77: I wondered too at first, but read the DATZ presentation again and there is no accurate locality given for L 77. it was just imported with some Geophagus sp. from the Parnaiba area, but who knows where exactly it was collected. Maybe it was not within the "Maranhão-Piauí ecoregion", which the paper is about.

Thanks for your input!

I too wondered if L077 was from a slightly different region, given not only that the information was vague in the DATZ article, but also that fish can be mixed together from nearby but different localities when shipped. I'm contemplating sending an email to the authors about what they know of the fish in the broader area, but so far work keeps me very busy so it won't happen soon.

Cheers, Eric

[Jools]

Below is how I got to it. You have to guess on the number of teeth, which is where I've probably gone wrong. Makes sense the new species is more compressed, has bigger mouth/more teeth, smaller eye and bigger caudal if you see from the maps it's in more upstream / faster water and so more adapted to brighter, shallower water and biofilm grazing. Also, back in the 1980s, makes sense the easier to reach common lower river species is the one being shown in DATZ (would be good to check if you're speaking with the authors).

Anyway, good to change the L-number and adding the n. sp. and more data...

Jools

Key to the species of

Hypostomus

from Maranhão-Piauí ecoregion

1a. Dark vermiculated color marks

Hypostomus vaillanti

(Fig. 7)

1b. Rounded dark spots 2

2a. Premaxilla and dentary, each with more than 100 teeth 3

2b. Premaxilla and dentary each with less than 100 teeth 4

3a. Anteromedial region covered by plates and odontodes and ventral lobe of caudal-fin much longer than dorsal lobe

Hypostomus johnii

(Fig.

3b. Anteromedial region deprived of plates and odontodes and the caudal-fin ventral lobe slightly longer than dorsal lobe

Hypostomus velhomonge

(Fig. 3)

4a. Body and head covered with spots usually smaller than the diameter of the eye

Hypostomus pusarum

(Fig. 9)

4b. Body and head covered with spots usually larger or the same size as the diameter of the eye, conspicuous and spaced

Hypostomus aff. pusarum

(Fig. 10)

[Jools]

Getting this updated today.

Jools