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FACTSHEETS: April 2011 - no. 178

Hoplisoma duplicareum Sands, 1995

he month of April 2011 heralds the return of aquarist and author Chris Ralph to lend his experience in keeping one of the more popular species of the Corydoradinae, Corydoras duplicareus..

Hoplisoma duplicareum

Hoplisoma duplicareum

Hoplisoma duplicareum (previously Corydoras duplcareus) belongs to the family Callichthyidae or armoured catfishes from South America; namely Brazil the Rio Puranga 8km north of the Nouba Ouba, prior to where it joins a small tributary of the Upper Rio Negro.

Hoplisoma duplicareum is not very common amongst aquarium imports from South America, but is well worth looking out for in my opinion. Over the last few years I have had the opportunity to keep this rather attractive species in my home aquaria. In its natural habitat Hoplisoma duplicareum will be found forming shoals amongst Hoplisoma adolfoi. This catfish is described as being very similar in appearance to H adolfoi which has a much thinner black band running from the base of the dorsal fin to the caudal fin forming a point and its pectoral fin spine is not serrated as in H. duplicareum.

This species prefers to be kept in water which has a pH in the range of 6.0-7.2 and hardness in the range of 2-20°dGH. It is ideally suited to temperatures in the range of 23-25ºC or 73-77°F.

I would suggest a minimum size of 24” x 15” X 12” for a small shoal of these fascinating little catfish. I would suggest good quality aquarium sand such as BD Aquarium Sand, or very smooth rounded gravel as the preferred substrate when keeping these catfish. The aquarium should provide some shelter in the form of rocks or bogwood along with some aquatic plants. As with all other species of fish, water quality and general husbandry is very important, and I would recommend that a minimum of 25% water is changed on a weekly to fortnightly basis.

Remarks: Corydoras duplicareus is placed in Lineage 9, the "short-snouted" species with the designated type species: C. punctatus. A revision in the future would constitute the resurrection of the genus name Hoplisoma (Agassiz, 1846).

As of the latest revision (Dias et al 2024) Corydoras duplicareus has now been placed in Lineage 9 and has the new genus name of Hoplisoma and a change to the specific name to duplicareum.

Common Name

False Adolfoi Catfish

Synonyms

Corydoras duplicareus

Family

Callichthyidae

Subfamily

Corydoradinae

Distribution

South America: Brazil, Rio poranga, 8 kilometres north of the Nobua oba, prior to where it joins a small tributary of the Upper Rio Negro.

Size

Male: 5.0cm (2ins) Female: 5.5cm (2¼ins)

Temp

23-25°C (73-77°F)

p.H.

6.0-7.2.

Hardness

2-20°dGH

Characteristics

The body shape of Hoplisoma duplicareum is described as being typical triangular Corydoras shaped. Described as having a slightly elongated body with a rounded snout. The caudal fin is described as being forked.

Colouration

The base colour of the body and head is described as being light tan. The ventrolateral scutes are described as being light tan in colour interspersed with gold coloured speckling mainly around the lateral line. The dorsolateral scutes are described as being dark black in colour, with the colouration extending from the base of the dorsal fin to the caudal fin (this black band can vary in depth and is documented as varying from 4-6mm). The dorsal fin is described as having a smattering of black colouration at its base; the remaining fins are described as being light tan in colour. This catfish has a dark coloured mask from the top of the head extending through the eyes towards the operculum. The tip of the snout in front of the eye mask is described as being light gold in colour. This catfish is described as having a gold coloured patch between the rear of the eye mask and the base of the dorsal fin.

Aquarium Care & Compatibility

Wherever possible I would recommend that the aquarist keep these catfish in a community aquarium in small groups of six or more, but as the absolute minimum I would suggest three specimens assuming that they are available in these numbers. In their natural habitat Hoplisoma duplicareum would be found in relatively large shoals.

Reproduction

There are documented records of Hoplisoma duplicareum having been spawned in aquaria. See article.

Sexual Differences

As with most other species of catfish the males tend to be more slender than the females. The females are described as being larger and plumper especially when ready to spawn. The males are described as being more strikingly coloured than the females.

Diet

As with all the other catfish that I have had the pleasure to keep over the years, Hoplisoma duplicareum readily accepts a mixed and varied diet which includes granular foods, frozen bloodworm and a good quality flake.

Glossary of Terms

Adipose: Defined as a second dorsal fin which in the case of Corydoras consists of fatty tissue with a single spine supporting a thin membrane.
Anal fin: Defined as the medial fin immediately posterior to the anus.
Caudal fin: Defined as the tail fin.
Caudal peduncle: Defined as the usually narrowing posterior part of the body between the anal and caudal fins.
Dorsal: Defined as being top or above.
Dorsal fin: Defined as the medial fin on top of the back.
Operculum: Defined as the large bone forming the gill cover.
Pectoral fins: Defined as paired lateral fins.
Scute: Defined as a bony plate.
Ventral: Defined as bottom, below or underneath.
Ventral fins: Defined as the paired fins between the pectoral and anal fins.

Etymology

duplicareum: from the Latin duplicare meaning to duplicate, alluding to the similar colour pattern shared with Corydoras adolfoi.

References

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.
Fuller, I.A.M. & Evers, H-G: 2005 Identifying Corydoradinae Catfish 384 p.

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ScotCat Sources

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Etymology-specific name

Online Sources

Fishbase

Catalog of Fishes

GBIF

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