Tenebrosum Cory (CW160 / CW168)
Hoplisoma tenebrosum (CW160 / CW168)
A genuinely rare Brazilian Cory-type catfish, formally described only in 2025 after being known to specialist aquarists for years under the aquarium codes CW160 and CW168.
Hoplisoma tenebrosum is an unusual armoured catfish from the Rio Tapajós drainage of the Brazilian Amazon. Before receiving its scientific name, different forms of this fish circulated in the aquarium hobby as CW160 and CW168, with differences in snout shape initially leading aquarists to believe they represented different lineages.
Detailed examination eventually showed that these forms belong to the same species. Hoplisoma tenebrosum was formally described in 2025 by Tencatt, Ohara, Carvalho, Grant and Britto.
The species has an immediately recognizable appearance: a dark mask crosses the eye, two to three dark horizontal stripes run along the body, and pale yellow-beige markings contrast against a warm brown to beige base colour. Settled fish can also show subtle greenish-yellow iridescence around the gill cover and shoulder area.
Why this fish stands out
- Formally described as a new species only in 2025
- Previously known to Cory collectors as CW160 and CW168
- Bold dark mask running through the eye
- Two to three distinctive horizontal dark body stripes
- Warm beige to brownish-yellow body coloration
- Subtle greenish-yellow iridescence when settled
- Unusual nocturnal behavior compared with many common Cory species
- Excellent species for advanced Corydoras and Hoplisoma collectors
Best for
- Advanced Cory collectors
- Rare South American fish collections
- Peaceful soft-water community aquariums
- Natural botanical and Tapajós-style setups
- Species-focused breeding projects
- Aquarists looking for rare Corydoras-type catfish in Canada
Topick Aquarium Insight
Hoplisoma tenebrosum should not be treated exactly like another common Bronze, Panda, or Sterbai Cory. One of the most interesting characteristics documented for this species is its strong tendency toward activity after dark.
Wild fish were observed and collected at night rather than during daylight hours. A newly introduced group may therefore spend considerably more time hidden during the day than customers expect from a typical Cory.
Shaded areas, wood, leaf litter, roots, and a dark substrate can help the fish settle. Their reluctance to remain exposed under bright lighting should not automatically be interpreted as poor health.
A larger group can also greatly improve confidence. We recommend keeping this rare species with several of its own kind rather than as a single collector specimen.
What Were CW160 and CW168?
Before Hoplisoma tenebrosum received its formal scientific description, aquarists knew visually similar fish under two different CW identification codes.
- CW160: historically associated in the hobby with a different snout form and at one time placed with the Brochis-type lineage
- CW168: historically treated as a Hoplisoma / Corydoras-type form
The 2025 scientific revision examined these differences and demonstrated that the variation in snout morphology was not sufficient to separate them. Both CW160 and CW168 are now included within Hoplisoma tenebrosum.
These CW numbers remain useful aquarium-trade search terms, especially for collectors who knew the fish before its formal description.
Appearance
The most recognizable feature of Hoplisoma tenebrosum is its bold striped pattern.
Mature fish typically display:
- A broad dark mask crossing the eye
- Dark pigmentation around the front of the dorsal fin
- Two or three dark brown to black longitudinal body stripes
- Pale yellow, cream, or beige markings on the head and upper body
- Warm beige to brownish-yellow base coloration
- Greenish-yellow iridescence around the operculum and shoulder area
Individual patterns naturally vary. Fish originating from different known localities can also differ in stripe width, with some populations developing noticeably broader stripes than others.
Hoplisoma tenebrosum vs Hoplisoma noxium
These two species were scientifically described together in 2025 and can appear superficially similar. Both can show a dark eye mask and pale body markings, but their flank pattern provides one of the easiest visual differences.
- Hoplisoma tenebrosum: typically has two or three solid dark longitudinal stripes along the sides
- Hoplisoma noxium: has dark spots and irregular blotches rather than the same solid horizontal stripes
Correct identification is particularly important for collectors and breeding projects involving these newly described Tapajós Cory species.
Origin & Natural Habitat
Hoplisoma tenebrosum is currently known from tributaries of the Rio Tapajós drainage around Maués, Amazonas, Brazil. Documented localities include the igarapé Água-branca, also called Ipixuna, the igarapé Palomita, and the igarapé do Roncador.
The species inhabits stream environments associated with sand, fine substrate, leaf litter, submerged wood, roots, and marginal cover. These environments provide an excellent model for a natural aquarium setup.
Unusual Nocturnal Behavior
One of the most fascinating aspects of this species is its activity pattern. Wild Hoplisoma tenebrosum were observed and collected at night rather than during daytime surveys.
This does not mean the fish will never become active during daylight in an aquarium. Captive-bred individuals can adapt to aquarium routines, but dim areas and shaded cover are strongly recommended.
Feeding shortly before or after the aquarium lights dim can also be useful when newly introduced fish remain shy.
Behavior & Group Size
Despite its unusual appearance and name, Hoplisoma tenebrosum is a peaceful social Cory-type catfish.
We recommend keeping at least 6 individuals. Groups of 8 or more are preferred when aquarium size and availability allow.
A proper group helps the fish establish normal social behavior and usually makes shy individuals significantly more confident.
Occasional trips to the surface to gulp atmospheric air are normal Corydoradinae behavior.
Tank Setup
A mature aquarium with soft substrate, shaded areas, and excellent water quality is ideal.
- 20 gallons or larger recommended for a group
- Long aquarium footprint preferred
- Fine sand strongly recommended
- Driftwood, roots, and leaf litter provide excellent cover
- Leave open sand areas for natural foraging
- Floating plants can help reduce intense overhead lighting
- Gentle to moderate current
- Good filtration and oxygenation
- Mature, biologically stable aquarium strongly recommended
Avoid sharp or abrasive substrate. Fine sand supports natural foraging while reducing the risk of damage to the fish's barbels and underside.
Water Parameters
- Scientific Name: Hoplisoma tenebrosum
- Aquarium Codes: CW160 / CW168
- Family: Callichthyidae
- Origin: Rio Tapajós drainage, Amazonas, Brazil
- Adult Size: approximately 5–6 cm
- Temperature: approximately 22–26°C
- pH: approximately 6.0–7.0
- Hardness: soft to moderately soft water preferred
- Temperament: Peaceful and social
- Diet: Omnivorous bottom feeder
- Care Level: Intermediate
Stable water conditions are more important than constantly adjusting the aquarium to reach one exact number. Rare wild-origin Corys should be acclimated carefully and protected from sudden changes in temperature or mineral content.
Feeding
Hoplisoma tenebrosum should receive a varied diet specifically delivered to the bottom of the aquarium. It should never be expected to survive only on leftovers from other fish.
- High-quality sinking Cory pellets
- Fine sinking granules
- Frozen bloodworms in moderation
- Frozen brine shrimp
- Daphnia
- Blackworms or tubifex from safe sources
- Small live foods
- Quality omnivore bottom-feeder foods
Shy newly imported individuals may feed more confidently in subdued lighting or shortly after the aquarium lights are reduced.
Tank Mates
In the aquarium, Hoplisoma tenebrosum is best combined with peaceful fish that will not intimidate or outcompete it.
- Small and medium peaceful tetras
- Rasboras
- Pencilfish
- Peaceful dwarf cichlids in appropriately sized tanks
- Other peaceful Cory-type catfish
- Small peaceful South American community fish
Avoid large predators, aggressive bottom dwellers, and highly boisterous fish.
Shrimp Compatibility
Adult freshwater shrimp can generally coexist with Cory-type catfish such as Hoplisoma tenebrosum. They are not specialized shrimp predators.
Extremely small shrimplets may still be eaten opportunistically, so a dedicated shrimp aquarium remains the best option when maximum shrimp reproduction is the goal.
Breeding
Unlike many newly described species for which aquarium breeding remains completely undocumented, Hoplisoma tenebrosum has already been successfully bred under aquarium conditions.
Healthy females become broader and fuller-bodied than males when mature. As with other Hoplisoma, breeding groups should be conditioned with a varied, protein-rich diet while maintaining excellent water quality.
Fresh water changes, good oxygenation, and stable soft-water conditions may help stimulate spawning. Adults do not provide parental care and eggs may need to be separated when deliberate fry production is the goal.
Because this remains a newly described and uncommon species, successful captive breeding is particularly valuable for maintaining healthy aquarium populations.
Special Handling & Transport Note
Hoplisoma tenebrosum requires additional care during handling and transportation.
The species was specifically named in reference to a powerful defensive secretion released under severe stress. Field collectors reported that other fish placed in the same confined transport water could be killed after this secretion was released.
This behavior is primarily a handling and transportation concern rather than a reason to fear the fish in a properly maintained aquarium. Stress should be minimized and livestock should always be transported using appropriate professional procedures.
As with other Cory-type catfish, the sharp dorsal and pectoral-fin spines should also be considered when netting or handling the fish.
Canada-Wide Live Fish Shipping
Hoplisoma tenebrosum is available from Topick Aquarium in Canada when in stock. Local pickup is available in Markham, Ontario, and Canada-wide live fish shipping may be available depending on weather, route, size, and livestock condition.
Important Note
Hoplisoma tenebrosum was formally described only in 2025. Older aquarium references may identify the same species as CW160, CW168, Brochis sp. CW160, or Corydoras sp. CW168.
Pattern, stripe width, snout shape, and body colour naturally vary between individuals and populations. This variation helped create multiple aquarium codes before the species was scientifically studied in detail.
This is a social species and should not be purchased as a single decorative bottom feeder. A suitable group, soft substrate, dedicated feeding, shaded cover, and stable water are strongly recommended.
FAQ
What is Hoplisoma tenebrosum?
Hoplisoma tenebrosum is a rare Cory-type armoured catfish from Brazil's Rio Tapajós drainage. It was formally described as a new species in 2025 after being known in the aquarium hobby under CW identification codes.
Is Hoplisoma tenebrosum CW160 or CW168?
Both. Fish historically identified in the aquarium hobby as CW160 and CW168 are now included within Hoplisoma tenebrosum.
Is CW160 the same fish as CW168?
They were historically separated partly because of differences in snout shape. Detailed scientific study showed that this variation occurs within the species, and both forms were assigned to Hoplisoma tenebrosum.
Is Hoplisoma tenebrosum a Corydoras?
It belongs to the Corydoradinae group of armoured catfishes commonly called Corys. Its valid scientific name is Hoplisoma tenebrosum. It was formally described after the modern reclassification of the traditional Corydoras group.
Is Corydoras tenebrosus the correct scientific name?
No. The species was formally described in 2025 as Hoplisoma tenebrosum. Corydoras-style names may still appear in older hobby listings and online searches, but Hoplisoma tenebrosum is the valid scientific name.
What does Hoplisoma tenebrosum look like?
Adults typically have a dark mask crossing the eye, two to three dark horizontal body stripes, pale cream or yellow-beige markings, and a warm beige to brownish base colour.
How big does Hoplisoma tenebrosum get?
Adults reach approximately 5–6 cm, with females generally becoming larger and fuller-bodied than males.
Is Hoplisoma tenebrosum nocturnal?
It shows an unusually strong tendency toward nighttime activity in nature. Wild specimens were observed and collected at night, so shaded areas and subdued lighting are particularly useful for this species.
How many Hoplisoma tenebrosum should I keep?
Keep at least six, with eight or more preferred when aquarium size and availability allow. They are social Cory-type catfish and should not be kept individually.
Does Hoplisoma tenebrosum need sand?
Fine sand is strongly recommended because it supports natural bottom-foraging behavior and is gentle on the barbels and underside of the fish.
What is the difference between Hoplisoma tenebrosum and Hoplisoma noxium?
H. tenebrosum typically has solid dark horizontal stripes along its sides, while H. noxium has more irregular dark spots and blotches rather than the same continuous striped pattern.
Can Hoplisoma tenebrosum be bred in aquariums?
Yes. Captive breeding has already been documented, although it remains a rare collector species and is far less commonly bred than mainstream Cory varieties.
Is Hoplisoma tenebrosum poisonous?
The species can release a powerful defensive secretion when severely stressed, particularly during capture and confined transport. This is mainly an important handling and shipping consideration rather than a normal danger in a stable home aquarium.
Can Hoplisoma tenebrosum live with shrimp?
Adult shrimp are generally compatible, although very small newborn shrimplets can never be guaranteed safe with an omnivorous fish.