Catfish / Pangassidae / Iridescent Shark Catfish

Iridescent Shark Catfish, Asian Shark Catfish, Siamese Shark
Pangasius hypopthalmus

Synonyms: Pangasius sutchi
Physical description: An elongated fish whose body resembles the body of a shark. The body is elongated and the tail is deeply forked. This fish has large eyes and a small mouth. The body is silver to blue with a silver iridescence. The back is darker than the main body color. A slender, horizontal, white stripe extends from the base of the tail to the gill cover. The fins are light gray to transparent.
Size/Length: To 40" (102 cm) in nature, Usually not more than 12" (30 cm) in captivity
Similar species: Other Pangasius species. A similar-looking species P. pleurotaenia is reportedly smaller in size. A strong, powerful fish. This fish is commonly kept in aquariums in the Middle East and Southeast Asia.
Habitat: Southeast Asia; found in large schools swimming in rapid areas of large rivers near Bangkok, Thailand. This catfish has been distributed throughout Southeast Asia as a food fish.
S: middle
Aquarium: A 48" (122 cm) or 55 gallon (209 L) tank is only suitable for young individuals under 6" (15 cm). They grow quickly and need a large open area for swimming. Does best in substantially larger tanks (exceeding 60"). Likes to have morning sunlight. The tank should be well-planted with well-rooted plants. Use a filter that provides a strong current.
Water chemistry: pH 6-7.8 (7.0), 2-20 dH (8), 72-86°F (22-30°C)
Social behavior: An active fish that usually will not bother smaller tank mates that it cannot swallow. Likes to school while young.
Suggested companions: Gouramis, Knifefish, Asian Catfish, Loaches, Cyprind sharks, larger barbs
FOOD: Young-live; Brine Shrimp, Tubifex , insect larvae; flakes; pellets. Adults-vegetables; lettuce, spinach, frozen peas; pellets; large flakes.
Sexual differences: Males have darker stripes and are more slender.
Breeding techniques: Bred in ponds in native lands for food and export. Breeding has not been successful in an aquarium, because of the necessary tank size.
Breeding potential: 10. This fish cannot be bred in aquaria.
Remarks: Many professionals feel that this fish should not be kept in a private aquarium because of its size. This species can only be kept as a juvenile. The Shark Catfish have very bad eyesight and are nervous fish. Try not to tap on the glass, turn on light when it is dark, or startle this fish in any way. This species has been introduced throughout Southeast Asia as a food fish. Older Shark Catfish lose their teeth and thus will not harm even small tank mates. An albino variation has been developed in Bangkok and is now widely distributed.
Difficulty of care: 4. Young fish are hardy and live foods on a regular basis. 6. Adults become very large and must be kept in a large tank. They are vegetarians.

By Rhett Butler   Mongabay.com