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Bagrichthys obscurus

Ng, 1999

Last revised 2026Edit this page

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This species is rare in the aquarium trade.
This species is rare in the aquarium trade.Nonn Panitvong/Siamensis.org

Quick factsEdit

Max size
249mm SL10in SL
Aquarium size
120 × 45cm48 × 18in
Temp
24–28°C75–82°F
pH
5.5–7.0
Hardness
1–15dGH

Difficulty6 of 8 measures

Moderate

How the rating is worked out

Space
large tank
Water
flexible
Temp
needs a steady temperature
Diet
unknown
Temperament
peaceful
Social
one male with several females
Compatibility
choose tankmates carefully

Other demands

Each of these can raise the rating on its own, whatever the measures above say.

Hardiness
unknown

Before you buy

  • Needs dither fish to settle

    It may be seen more often if maintained alongside schools of 'dither' fishes, for which good choices include larger rasboras, medium-sized barbs or perhaps the glass catfish Kryptopterus minor .

Bagrichthys obscurus is a bagrid catfish from the Chao Phraya, Bang Pakong and Mekong watersheds in Thailand, Cambodia and Vietnam. One of the lancers, named for the extended dorsal spine in several members of the genus, it has a uniformly brown body with no pale stripe or blotches, a small mouth and a relatively short dorsal spine. It inhabits large, turbid rivers with slow flow, and is shy, nocturnal and territorial towards other bottom-dwellers.

Distribution

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Described from Roi Et province, northeastern Thailand and distributed throughout the Chao Phraya, Bang Pakong and Mekong watersheds. Recorded from parts of the latter in Cambodia and Vietnam and presumably also occurs in Laos.

Typically inhabits large, turbid rivers with muddy substrates and slow flow and moves moves into flooded riparian zones to spawn during the wet season.

Aquarium size

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Standard length
249mm SL10in SL
Aquarium base
120 × 45cm48 × 18in
Volume
~243litres~64US gal

A tank with base measurements of 120 ∗ 45 cm48 ∗ 18 in should be the smallest considered.

Maintenance

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A shy, nocturnal species so best maintained in a dimly-lit aquarium. Provide plenty of hiding places in the form of clay flowerpots, lengths of plastic piping, driftwood tangles etc.. Plants are not essential but useful in reducing the amount of light hitting the bottom of the tank as well as offering cover.

If you're keeping multiple specimens or other similarly-sized catfishes try to arrange the décor in such a way as to form distinct territories.

The heater should also be placed in such a way that it doesn't allow the fish to rest behind or against it. Also note that this species doesn't appreciate strong water flow.

Water conditions

Edit
Temperature
24–28°C75–82°F
pH
5.5–7.0
Hardness
1–15dGH

These recommendations come from this profile’s own figures. They contain affiliate links, so we may earn a commission.

Apparently feeds on small, benthic animals and organic detritus in nature but will accept most aquarium foods.

Small live and frozen fare such as Artemia, Tubifex, bloodworm, etc. are particularly suitable, and high-quality, sinking dried products enriched with Spirulina or other vegetable content should also be offered regularly.

Behaviour and compatibility

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Peaceful with species inhabiting other areas of the tank and has a relatively small mouth so is unable to swallow anything larger than a few millimetres in length.

It may be seen more often if maintained alongside schools of 'dither' fishes, for which good choices include larger rasboras, medium-sized barbs or perhaps the glass catfish Kryptopterus minor.

It is territorial towards other benthic species, especially conspecifics, and males in particular will not often tolerate each other in all but the largest aquaria. Keep a single male alongside 3 or more females for the best chance of long-term success as this should help reduce the chance of any single individual being targeted by the dominant male.

Sexual dimorphism

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Males possess a pointed, externally visible genital papilla located just anterior to the anal fin and noticeably longer barbels, while sexually mature females are normally slightly larger-bodied.

Reproduction

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Unrecorded in captivity as far as we know. In nature adults move into temporarily-flooded areas at the onset of the wet season to spawn.

Notes

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The vernacular name 'lancer' is derived from the extended dorsal spine possessed by several members of the genus, which currently contains 7 species.

B. obscurus is diagnosable from congerners by the following combination of characters: mouth opening relatively small and narrow; oral dentition significantly reduced; dorsal-fin spine relatively short with 15 or less serrae; inner and outer mandibular barbels crenulated; relatively slender body (depth at anus 15.1 - 18.4 % SL; caudal peduncle depth 6.7 - 8.3 % SL); short adipose fin (base length 43.3 - 48.9 % SL); genital papilla in males touching the first anal-fin ray; body colour uniformly brown with no pale midlateral stripe or blotches.

References

  1. Ng, H. H. (1999). Bagrichthys obscurus, a new species of bagrid catfish from Indochina (Teleostei: Bagridae). Revista de Biologia Tropical 47(3), 545 - 552
  2. Linder, R. S. and H. H. Ng (2002). Notes on the Lancers of the Genus Bagrichthys (Teleostei, Bagridae) Cat Chat: The Official Journal of The Catfish Study Group 3(3)

Distribution

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