Given the CorydorasWorld CW
number of 154 before being described in 2020 as Corydoras
rikbaktsa (now Hoplisomarikbaktsa).
Habitat: Known from three localities, two
of which are small tributaries of the rio Juína-Mirim
west of the city of Juína, near the water divide
with the rio Aripuanã (upper rio Madeira basin),
and the third one a tributary of the Rio Papagaio
below the Cachoeira de Utiariti. All known localities
are in the Rio Juruena basin (Rio Tapajós basin),
Mato Grosso, Brazil. Lineage: Corydoras
rikbaktsa could be assigned to either Lineage
6 or Lineage 9, both of which include short and intermediate
short/long snout species. Both lineages share the
following combination of features: pectoral spine
with weakly to moderately developed serrations (vs.
well-developed), perpendicularly or obliquely oriented
in relation to main axis of spine (vs. curved or laminar),
and directed towards its tip (vs. directed towards
its origin); posterior margin of the dorsal spine
with serrations directed towards its tip (vs. directed
towards its origin); infraorbital 1 generally with
poorly to moderately developed ventral laminar expansion
(vs. well-developed); and infraorbital 2 generally
not contacting compound pterotic (vs. in contact).
Currently no morphological diagnosis allowing the
assignment of a given Corydoras/Hoplisoma
species to either of these two lineages is available
(Lima & Britto, 2020). As
of the latest revision (Dias
et al 2024) Corydoras rikbaktsa
has now been placed in Lineage 9 and has the new genus
name of Hoplisoma. Aquarium
Care: This is akin to most of this genus,
very peaceful, and would be best housed with small
to medium sized tankmates such as Tetras, Rasboras
and Danios or in a species tank for breeding purposes.
Best to purchase 6 individuals or more as they will
be happier in a group. Diet: Readily
accepts a mixed and varied diet which includes granular
foods, tablet food, frozen bloodworm and a good quality
flake. Etymology: The specific name
honours the Rikbaktsa (also known as Rikbakta or Erikbaktsa),
a Jê-speaking indian nation, who formerly inhabited
the area between the Rio Juruena and Rio Aripuanã
in northern Mato Grosso. Their first contacts with
the western world happened when they clashed and fought
rubber-tappers encroaching on their territories during
the 1940´s and 1950´s. They were subsequently
contacted by Jesuit priests (and almost completely
wiped out by contagious diseases) during the 1960´s.
During the 1990´s the Rikbaktsa finally obtained
the demarcation of three non-contiguous lands (Hemming,
2003). Remarks:
This species is
still found on some online sources as Corydoras
rikbaktsa.
Common
Name:
CW154
Synonyms:
Corydoras
rikbaktsa
Family:
Callichthyidae
Distribution:
South America:
Brazil, State of Gois, Rio Ituna & Rio Itata,
tributaries of the lower Rio Xingu oposite Altamira.
Size:
Male: 4.5cm (1¾ins)
Female: 5.0cm (2ins)
Temp:
23-27°C (73-81°F)
p.H.
6.0-7.0.
Reference:
Alexandrou, Markos
& Taylor, Martin. (2011). Evolution,
ecology and taxonomy of the Corydoradinae revisited. Angelica C Dias, Luiz F C Tencatt, Fabio F
Roxo, Gabriel de Souza da Costa Silva, Sérgio
A Santos, Marcelo R Britto, Martin I Taylor, Claudio
Oliveira, Phylogenomic analyses in the complex
Neotropical subfamily Corydoradinae (Siluriformes:
Callichthyidae) with a new classification based on
morphological and molecular data, Zoological Journal
of the Linnean Society, 2024;, zlae053.
Lima, Flávio
& Britto, Marcelo. (2020). A new Corydoras
(Ostariophysi: Siluriformes: Callichthyidae) with
an unusual sexual dimorphism from the rio Juruena
basin, Brazil. Zootaxa. 4742. 518-530. 10.11646/zootaxa.4742.3.6. www.corydorasworld.com
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