Catfish of the Month Right Arrow May 2018 • Article © Julian Dignall, uploaded May 03, 2018

Tandan, Australsk Ferskvandsmalle (Denmark), Dewfish, Eel Tail Catfish, Freshwater Catfish, Tauwels (Germany) - Tandanus tandanus   (Mitchell, 1838)

Wombats, Kangaroos and Quolls - the beautifully preposterous Duck Billed Platypus; these are just a very few of the better-known mammals of Australia. They are remarkably different from anything found elsewhere in the world. In aquatic circles, Australasian fishes, especially the Melanotaeniidae (Rainbowfishes) are well known and perhaps not quite as odd in comparison to the mammals I mention. Thankfully, Australian catfish are a welcome return to wacky form. They are odd looking indeed.

Catfish from this region belong to the family Plotosidae, a few species are marine or brackish but the majority are freshwater fish and, from time to time, exports are made. Tandanus tandanus are now protected in South Australia and Victoria states.

T. tandanus is larger catfish and is a valued food fish because of its flavoursome meat. Moreover, it is reasonably easy to catch although transferring from hook to plate is not without risk. Their sharp dorsal and pectoral spines will, if carelessly handled, puncture the skin and cause disproportionate pain for hours, and if not treated a few days or more.

Tandanus have an uninterrupted anal fin which is connected to the caudal fin and ends just posterior behind the dorsal; this gives an eel like appearance in young fishes although more mature fish are way too stocky to be thought of as a classic eel shape. In any stage of life, these fins and the six short, thick barbels and large eyes provide an unusual and appealing look. Although colouration is by no means striking being a mottled rusty-brown to olive green over the back and side three quarters, the underside is a plain creamy white. Colouration changes depending on surroundings and mood.

In its native habitat, they feed on insect larvae, prawns, crayfish, molluscs and small fish. In captivity, growing these fishes up to their large adult size is rewarding and straightforward. They readily eat prepared food in addition to similar food items to that which they encounter in the wild. Fed well, they grow quickly and are neither territorial nor aggressive. At any age, they are inquisitive and active fishes – ensure a tight-fitting lid and robust decorations and can be considered a true pet fish that will live for a decade or more.

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Jump to next section Cat-eLog Data Sheet
Scientific Name Tandanus tandanus  (Mitchell, 1838)
Common Names Tandan
Australsk Ferskvandsmalle (Denmark), Dewfish, Eel Tail Catfish, Freshwater Catfish, Tauwels (Germany)
Type Locality Lagoon near Tangulda, Namoi River, New South Wales; river between Gwydir River and MacIntyre River, New South Wales, Australia.
Synonym(s) Plotosus tandanus
Pronunciation Tahn dah ness - tahn dah ness
Etymology The origin of the name is unclear. Possibly from an Australian Aboriginal name for the fish. 
Article - Shane's World Species How to Put a Tandanus in Your Tank
Jump to next section Species Information
Size 850mm or 33.5" SL. Find near, nearer or same sized spp.
Identification Second dorsal fin originating above middle of body. Smaller fish (>30 cm) have a mottled coloration.
Sexing Males possess a long cylindrical genital papilla and females a triangular one.
Jump to next section Habitat Information
Distribution Eastern Australia.
Australia waters, Eastern Australia Waters (click on these areas to find other species found there)

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pH 6.4 - 8.0
Temperature 10.0-26.0°C or 50-78.8°F (Show species within this range)
Jump to next section Husbandry Information
Feeding Feeds on small crustaceans, insects, snails and small fishes in the wild. Carnivorous but not a fussy eater in the aquarium. Will take most frozen/live/prepared foods, especially meaty types.
Furniture Found in slow-flowing rivers and lakes with fringing vegetation, being more common in the latter. Hiding spaces in the form of PVC pipes and/or driftwood are necessary.
Compatibility A peaceful, solitary species. Juveniles may form loose aggragations. Should not be kept with smaller fishes.
Breeding Spawns when temperatures rise to between 20-24?Cduring spring and summer. Spawning is not stimulated by flooding. The number of eggs increases with size, ranging from about 2800 to 20600 eggs in females between 390 and 530 mm long. They build a circular to oval nest, generally around 0.6-2.0 m in diameter, from pebbles and gravel. During courtship, both male and femal circle and weave about the nest. The female then arches her body, agitates her pelvic fins and releases eggs about 30 cm above the nest. The eggs are spherical (about 3 mm in diameter), non-adhesive, and a light greenish yellow in color. The male fertilizes the eggs, which sink to the botom and settle into the gravel of the nest. One of the adults, usually the male, will remain at the nest until the eggshatch in about 7 days. The larvae are about 7 mm long when hatched, and barbels appear after 3 days.
Breeding Reports There is no breeding report.
Jump to next section Further Information
References Interior Aust.v. 1 - ppopp. 44, 95 - Pl. 5 (fig. 2)
McDowall, RM, 1996. Freshwater fishes of south-eastern Australia. Reed Books, Chatswood. 247 pp.
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Last Update 2014 Jun 18 09:22 (species record created: 2018 May 03 13:58)

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