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 e are continuing the predator theme this month ( Nov.2004) with another beastie, the "Helicopter catfish" from the upland rivers in Thailand down to Indonesia. This species of Wallagonia is not exported as much as its cousin Wallago attu but a few aquatic publications have W. leeri captioned as W. attu and I will point out the differences later in these two closely related species.

Wallagonia leerii

First of all we at ScotCat must stress that this is not really a catfish to keep in your aquarium and as they are creeping up more and more on importers lists you must keep in mind that it can grow to a mostly unmanageable 6ft in length and would need a fish only diet the older it gets, as you can tell by the girth of its mouth. It strikes me as strange that it is now offered to unsuspecting aquarists although these specimens were in very good condition and were around 18inchs in length when photographed in the aquatic stores tanks.

Wallagonia leerii

To distinguish W. attu from the very similar W. leeri you have to look at the dorsal fin first. W. attu has a pointed extension while W. leerii does not and is more rounded at the tip. The mouth gape of W. attu ( see above) reaches beyond the insertion of the eye and W. leerii has the mouth only reaching to the beginning of the eye. W. attu has a longer anal fin than W. leerii with 77- 97 with the latter possessing between 64-75 fin rays. You can see below the massive mouth and the rows of conical teeth.

There are at present 5 species of Wallago listed on Fishbase (2010), our factsheet of the month Wallago leeri, now Wallagonia leerii, W. attu, W. hexanema, (which is probably W. attu, W. maculatus, and a new species which was described in 2004 by Heok Hee Ng from mainland Southeast Asia, Wallago micropogon, now Wallagonia micropogon

Wallago attu - view of mouth

To distinguish W. leerii from the very similar W. attu you have to look at the dorsal fin first. W. attu has a pointed extension while W. leerii does not and is more rounded at the tip. The mouth gape of W. attu (see above) reaches beyond the insertion of the eye and W. leerii has the mouth only reaching to the beginning of the eye. W. attu has a longer anal fin than W. leerii with 77- 97 with the latter possessing between 64-75 fin rays.

Remarks: Cited in Fishbase as Wallago but in the Catalog of Fishes in the current status (2018) Wallagonia micropogon is stated to be a synoymn of Wallagonia leerii and could be the one and same species. The diferences between Wallago and Wallagonia are complex and are due to the different bone structures. Wallagonia was placed by Myers (1948) and nearly all subsequent authors as a junior synonym of Wallago, but it is was later recognised as a distinct genus by Roberts, T. R. 2014.

Helicopter catfish, Trey stuak (local name)

Wallagonia miostoma,Wallago nebulosus, Ompok nebulosus, Wallago miostoma, Wallagonia tweediei, Wallago tweediei

Silurinae

Asia: Thailand to Indonesia.

180.0cm (6ft)

20-25ºC (67-77°f)

5.5-7.0.

Body elongated, compressed. Abdomen rounded. Head large, depressed. Snout spatulate, somewhat protruded. Teeth villiform in bands on jaws and in patches on palate. Two pairs of barbels, one pair each of maxillary and mandibular. Mouth reaching to anterior margin of eye. Mandibular barbels shorter than pelvic fin. 12-16 gill rakers on 1st arch. 64-75 anal fin rays.

Light golden brown on upper body with broad black band reaching to caudal peduncle from posterior of insertion of dorsal fin. Silver spangle effects adorning this band. Older larger adults lose this colouration and tend to be all over silver.

This catfish is not meant to be in an aquarium as it will view any other fish as lunch. Only suited to very experienced aquarists who can give this catfish an indoor heated pond and plenty of room.

Not possible in an aquarium setting as in their local habitats they leave the deeper water and spawn in the shallows.

As juveniles they will eat pellet and tablet foods and meaty foods such as earthworms and beef heart. As adults they will only except a living fish diet.

Walago(nia): Bleeker, in 1851 took the Indian fish name 'Wallagoo', gave it generic rank, and used it in connection with a new species.
leerii: Named in honour of Leer.

Baensch, H.A. and R. Riehl 1985 Aquarien atlas. Band 2. Mergus, Verlag für Natur- und Heimtierkunde GmbH, Melle, Germany. 1216 p.
Rainboth J. Walter; Fishes of the Cambodian Mekong. FAO Rome 1996.
Froese, R. and D. Pauly. Editors. 2004. FishBase. World Wide Web electronic publication. www.fishbase.org, version (09/2004).
Ng, H. H. 2004. Wallago micropogon: A new species of silurid catfish (Teleostei: Siluridae) from mainland Southeast Asia. Copeia, 2004 (1): 92-97. [1].
Jayaram, K.C.; The Freshwater Fishes of India, Pakistan, Bangladesh, Burma and Sri Lanka - A Handbook. Zoological Survey of India, Calcutta 1981 p.206-210.

Photo Credits

© Allan James @