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 ith the onslaught of C & CW numbers in the last twenty years or so we tend to forget these species that were a staple diet of the catfish hobby in the 1970s and 80s and one of them was at this time a well sought after species alongside "The Bandit Catfish" Hoplisoma metae (previously Corydoras metae) and that was Hoplisoma melini (previously Corydoras melini).

Hoplisoma melini

There is a similar undescribed species with the c-number of Hoplisoma sp. (C084), which comes from the Rio Tiquié in Brazil close to the Colombian border, this species grows larger and has a broader black body stripe, this species lives alongside Hoplisoma tukano in the Rio Tiquié.

Hoplisoma sp. (C084)

There are also a few other classic look-a-likes, Hoplisoma davidsandsi, (Black, 1987) Hoplisoma metae (Eigenmann,1914) and the undescribed species Corydoras sp.(C016) (which is the 'saddle nosed' relative to C. melini from lineage 1) springs to mind. H. melini can be confused with H. davidsandsi and H. metae but the revealing factor is the position of the black body stripe on H. metae which runs over the ridge of the back whereas in H. melini it breaks and divides into two over the back and continues to almost the end of the lower lobe of the caudal fin, in other words it shows the body colouration on the ridge of the back, while H. metae, on the ridge of the back, is black.

The H. davidsandsi connection has H. melini having the same black body stripe ending on the bottom lobe of the caudal fin, but the stripe separates just behind the dorsal fin and continues as two lines over the back of the body wheras H. davidsandsi has this black stripe covering the ridge of the back, and the stripe continueing through the bottom lobe of the caudal fin. The colouration is also different with H. melini being a dirty white with black specks to the edges of the body scutes, while H. davidsandsi has a tan colouration with no specks.

Distrbution: Colombia, Brazil, border region, confluence of Rio Papuri and Rio Uaupes, at Luarete.

Hoplisoma davidsandsi

Hoplisoma metae

The above images show the two most look-a-likes to H. melini.

Remarks: Corydoras melini belongs to Lineage 9 along with C084, C. davidsandsi and C. metae which includes the classic "short-snouted" species. A revision in the future would likely resurrect the genus name Hoplosoma (Agassiz, 1846), with the designated type species of C. punctatus. This is a very species-rich lineage and many of the species are relatively recently evolved. This species is still found on some online sources as Corydoras melini.

Update: As of the latest revision (Dias et al 2024) Corydoras melini has now been placed in Lineage 9 and has the new genus name of Hoplisoma.

Corydoras melini

None

Corydoradinae

South America: Upper Negro and Meta River basins. Type locality: Jauareté an dem Ausfluss des Rio Papuri in den Rio Uaupés, Brazil.

Male: 4.0cm (1½ins), Female: 4.5cm (1¾ins)

22-25°C (71-77°F)

6.0-7.2.

Body short and compact. A wide black band runs diagonally from the dorsal fin spine to the lower apex of the caudal fin. It is broad at the beginning and becomes wedged shaped. A wide band extends over and below both eyes, bridging the top of the head. Sometimes a line of spots runs from the gill covers along the lateral line, and between this and the major some pale striping is visible. The gill covers have a golden-yellow shimmer.

Body colour beige or brown, dorsal fin yellowish and transparent, with the front half of the fin having a dark colouration extending to the apex. A wide black band runs diagonally from the dorsal fin spine to the lower apex of the caudal fin

Good addition to an average sized community tank. Purchase at least six specimens to form a group. Provide a sand substrate in a planted aquarium with some hiding places to make your Corydoras/Hoplisoma feel secure.

This is akin to most of this genus, very peaceful, and would be best housed with small to medium tank mates such as Tetras, Rasboras and Danios or in a species tank for breeding purposes.

Best to provide the ratio of two males and one female. Breeding in the typical Corydoras "T" formation. The eggs, which are approximately 2.2mm in diameter, and are usually laid in Java Moss. The eggs are not very adhesive and are easily damaged if you try to move them. The eggs hatch in four days. For more information on breeding Corydoras/Hoplisoma go to the breeding articles section of the website.

Males are more slender than the females and the ventral fins in the female are rounded whilst the males are pointed.

Adults can be fed the usual good quality flake food, frozen bloodworm, tablet foods, white and grindal worms. For new born fry the usual fare of microworm, fry flake and brineshrimp after the fry have used up their yolksac.

Caudal fin: The tail.
Caudal peduncle: The narrow part of a fish's body to which the caudal or tail fin is attached.
Dorsal fin: The primary rayed fin(s) on top of the body.
Gills: The organs utilized to obtain oxygen from the water.
Lateral line: A sensory line, along the sides of the body.

melini: Named in honour of Swedish herpetologist Douglas Melin, who collected the type series.

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.
Ferraris, C.J. Jr., 2007. Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. Zootaxa 1418:1-628.
Ian A. M. Fuller & Hans-Georg Evers 2011, Identifying Corydoradinae Catfish: Aspidoras-Brochis-Corydoras-Scleromystax-C-numbers & CW-numbers 141p. Ian Fuller Enterprises.
Seus, Werner: Corydoras, The most Popular armoured catfishes of South America.
TUBS creativecommons.org
www.corydorasworld.com

Photo Credits

Top image: © Allan James @
Second Image: © Hans-Georg Evers
Third image: © Mona Opland
Fourth image: © Johnny Jensen ©