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FACTSHEETS: March 2006 - no. 117

Pangasianodon hypophthalmus (Sauvage, 1878)

his month we welcome back regular U.K. contributor Chris Ralph with his insight on the "Iridescent Shark", Pangasianodon hypophthalmus , and his trepidation on keeping this large catfish in the home aquarium.

Pangasianodon hypophthalmus is a catfish which should never be imported due to the eventual size that it can attain, and the fact that it is a very nervous and skittish fish, which does not fare well in the confines of cramped aquaria. All too often this catfish is offered for sale as a juvenile fish at around 75-100mm and is quite often labelled as Pangasius sutchi or Iridescent Shark.

Pangasianodon hypophthalmus

Pangasianodon hypophthalmus

A couple of years ago whilst on a day out with Kate looking at some aquatic retailers we were horrified to find that this catfish was being offered as the fish of the week on a buy one get one free basis. Needless to say we shall not be venturing back to that retailer. If only these catfish remained small and manageable, but alas they do not.

These catfish are bred commercially in large ponds for the aquarium trade, which begs the question why? Obviously there is a demand or else this trade would not exist, how we control the importation of these fish is another story! Who in their right mind would want to keep a catfish that is capable of weighing in excess of 44kg?

Pangasianodon hypophthalmus = albino

Pangasianodon hypophthalmus - albino

There is also an albino form of this catfish which is also offered for sale. It is documented that this is a migratory species of catfish moving upstream to spawn in May-July. This fish has been introduced to other countries other than those documented below which include Bangladesh, Philippines, Singapore and Taiwan.

Aquarium size would need to be as large as possible but as an absolute minimum for a 450mm specimen I would suggest a 72” x 24” x 24” aquarium, even though I do not advocate the keeping of these catfish.

Common Name

Iridescent Shark, Sutchi catfish or Pla Sawai

Synonyms

Pangasius pangasius, Helicophagus hypophthalmus, Pangasius pleurotaenia, Pangasius sutch, Pangasius hypophthalmusi

Family

Pangasiidae

Subfamily

Distribution:

Southeast Asia: Namely the Mekong, Chao Phyra and perhaps Mekong basins; Thailand, Laos, Cambodia and Viet Nam. It is documented that this catfish has been introduced into additional river basins for the purposes of aquaculture.

Size

1300mm or 52” SL (standard length is the measurement from the tip of the snout to the base of the caudal peduncle).

Temp.

The ideal temperature range is 22-26°C.

p.H.

The ideal range is 6.5-7.5

Hardness

2-29°dGH

Characteristics

The body is best described as being elongated. The position of the mouth is described as being terminal. There are 6 branched dorsal fin rays and the pelvic fins have 8-9 soft rays. The gill rakers are described as being normally developed, with small gill rakers being interspersed with larger ones.

Colouration

The fins of this catfish are dark grey or black in colour. Juvenile specimens are described as having a black stripe along the lateral line with a second long black stripe below the lateral line. Adult fish are described as being uniformly grey in colour. These catfish have a dark stripe on the middle of the anal fin and a dark stripe in each of the caudal lobes.

Aquarium Care & Compatibility

Whilst this catfish is fairly peaceful avoid keeping it with small fish as they will eventually appear on the menu. It is best to keep this catfish with other large fish avoiding those species that are too boisterous.

Reproduction

There are no known records of aquarium spawnings of this catfish, which is most likely due to the adult size of these fish and the enormous size of aquarium required. To be honest it is quite a relief that these fish have not been bred in aquarium conditions.

Sexual Differences

It is documented that the males have darker stripes and are more slender than the females.

Diet

This catfish is best described as being an omnivore feeding on a mixed and varied diet that includes catfish pellets, catfish tablets, frozen bloodworm, floating food sticks and vegetable matter to name but a few.

Glossary of Terms

Gill rakers: Structure on the upper portion of the gill arches.
Lateral Line: A sensory line, along the sides of the body.

Etymology

Pangasianodon: Pangasius + an (Greek for without)+odon (Greek for tooth); in reference to the toothless state of the adult fish.
hypophthalmus: With an eye-spot below, (under).

References

Baensch, H.A. and R. Riehl 1985 Aquarien atlas. Band 2. Mergus, Verlag für Natur- und Heimtierkunde GmbH, Melle, Germany. 1216 p.
Catfish Association Great Britain Volume 1.
FishBase - www.fishbase.org.
Planet Catfish - www.planetcatfish.com.
Published in Practical Fishkeeping January 2006.
ScotCat – www.scotcat.com.

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ScotCat Sources

Article

Etymology-genera

Etymology-specific name

Online Sources

Fishbase

Wikipedia

Catalog of Fishes

GBIF

Fishnet2

iNaturalist