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Heptapterus carmelitanorum, a new species from the upper Paraná River

Posted: 08 Sep 2022, 15:49
by bekateen
, new species

Deprá GC, Aguilera G, Faustino-Fuster DR, Katz AM, Azevedo-Santos VM (2022) Redefinition of Heptapterus (Heptapteridae) and description of Heptapterus carmelitanorum, a new species from the upper Paraná River basin in Brazil. Zoosystematics and Evolution, 98(2): 327-343. https://doi.org/10.3897/zse.98.89413

https://zse.pensoft.net/article/89413/list/9/
Abstract
A new diagnosis and a new classification of Heptapterus are provided and a new species, H. carmelitanorum, is described. Heptapterus is diagnosed by the following character combination: adipose fin confluent with the caudal fin; non-bifurcate caudal fin; anal-fin insertion posterior to vertical through adipose-fin insertion; 10–23 anal-fin rays; anal fin not confluent with caudal fin; and extremely elongate body, with a head length of 16.1–24.9%SL. Species included in Heptapterus are H. borodini, H. carmelitanorum, H. carnatus, H. exilis, H. hollandi, H. mandimbusu, H. mbya, H. mustelinus, H. ornaticeps, and H. qenqo. Some of the character states diagnosing H. carmelitanorum among its congeners are the anal-fin insertion less than one eye diameter posterior to a vertical through the adipose-fin insertion (vs. more than one eye diameter in all congeners); the isognathous mouth (vs. slightly to moderately retrognathous, except H. borodini); and the keel formed by ventral procurrent caudal-fin rays shallow, far from reaching anal-fin base (vs. keel formed by ventral procurrent caudal-fin rays deep, continuing almost to the anal-fin base, except in H. borodini and H. hollandi).
Key Words:
Chasmocranusbrachynema, Grande River basin, , , , Minas Gerais, , Sapucaí River basin, Siluriformes

Re: Heptapterus carmelitanorum, a new species from the upper Paraná River

Posted: 08 Sep 2022, 20:49
by bekateen
Besides describing a new species, this paper also redefines the genus Heptapterus as follows. Diagnosis of Heptapterus:
  • Adipose fin extensively fused with the caudal fin;
    Figure 2. Schematic representation of the different degrees of proximity and connection between the adipose and caudal fins in Heptapterini. a. Adipose and caudal fins widely separate, as in Imparfinis piperatus, for instance; b. Adipose fin reaching the caudal fin, but not connecting to it (i.e., connective tissue in which dorsal procurrent caudal-fin rays are imbedded is not contiguous with connective tissue forming the adipose fin), as in Chasmocranus longior, for instance; c. Adipose fin connecting with caudal fin (i.e., connective tissue in which dorsal pro-current caudal-fin rays are imbedded is clearly contiguous with connective tissue forming the adipose fin), as in Heptapterus.
    Figure 2. Schematic representation of the different degrees of proximity and connection between the adipose and caudal fins in Heptapterini. a. Adipose and caudal fins widely separate, as in Imparfinis piperatus, for instance; b. Adipose fin reaching the caudal fin, but not connecting to it (i.e., connective tissue in which dorsal procurrent caudal-fin rays are imbedded is not contiguous with connective tissue forming the adipose fin), as in Chasmocranus longior, for instance; c. Adipose fin connecting with caudal fin (i.e., connective tissue in which dorsal pro-current caudal-fin rays are imbedded is clearly contiguous with connective tissue forming the adipose fin), as in Heptapterus.
  • caudal fin non-bifurcate (i.e., caudal fin not divided in two lobes; vs. bifurcate, with distinct dorsal and ventral lobes);
  • dark bars and stripes on back of trunk (vs. absence of dark bars and stripes on back of trunk);
  • 5-6 pairs of pleural ribs (vs. 8-9 ribs);
  • elongate body with a head length of 16.1-24.9% (vs. 25.5-27.3%);
  • posterior extension of mouth rim short, with rictus barely reaching vertical line through posterior nostril (vs. posterior extension of mouth rim longer, with rictus reaching vertical line between posterior nostril and eye);
  • premaxillary tooth plate with no posterolateral extension, or with a small one (vs. with a very long posterolateral extension);
  • pelvic-fin insertion posterior to vertical through insertion of dorsal fin (vs. anterior) and anal-fin insertion posterior to vertical through adipose-fin origin (vs. anterior);
  • 10-23 anal-fin rays (vs. 33-46);
  • anal and caudal fins separated (vs. anal fin confluent with the caudal fin); and
  • supraorbital pore 6 (s6) fused or closer to each other (vs. separate and closer to the eye than to each other).[/quote]

Re: Heptapterus carmelitanorum, a new species from the upper Paraná River

Posted: 08 Sep 2022, 21:27
by bekateen
This paper moves two Imparfinis species into Heptapterus: The paper also bumps several existing species of Heptapterus into different genera or into an enigmatus status in the genus: The authors refer to them as 'Heptapterus' to suggest an incertae sedis status; they probably deserve to be in a different genus.

Renamed species: Incertae sedis species: Finally, one more impact of this paper is that all three of the undescribed Heptapterus we have listed as sp(1), sp(2) and sp(3) are no longer Heptapterus. The photos of these fish clearly show that their adipose fins and caudal fins do not come into contact (as shown in figure 2, attached in the above post), and thus they are not in the genus Heptapterus. Instead, based on an illustration in this new paper, the fish have an adipose fin-caudal fin association (or lack thereof, really) consistent with Imparfinis:

Re: Heptapterus carmelitanorum, a new species from the upper Paraná River

Posted: 10 Sep 2022, 08:10
by Jools
Thanks for all the effort updating the cat-elog with these changes.

Cheers,

Jools