Hemibagrus wyckioides
Asian Red Tailed Catfish
SynonymsTop ↑
Macrones wyckioides Fang & Chaux, 1949; Mystus aubentoni Desoutter, 1975; Mystus wyckioides (Fang & Chaux, 1949); Macrones wyckioides Fang & Chaux, 1949
Etymology
Hemibagrus: from the Greek hemi, meaning ‘half’ and the generic name Bagrus.
Classification
Order: Siluriformes Family: Bagridae
Distribution
Type locality is given simply as ‘Cambodia’, but this species is currently considered to occur throughout much of the Mekong river system in China, Laos, Vietnam, Cambodia and Thailand plus the Chao Phraya drainage in Thailand.
Some records pertaining to H. nemurus from the Lancangjiang (upper Mekong) basin in Yunnan province, southern China, relate to H. wyckioides, with the former actually restricted to the island of Java, Indonesia.
Habitat
Inhabits main river channels, including whitewater rapids, and performs localised migration into flooded forest during the wet season from July to October.
Maximum Standard Length
The largest bagrid species in central Indochina reaching at least 900-1000 mm and 70-80 kg in weight.
The largest specimen known to date measured 1300 mm.
Aquarium SizeTop ↑
Suitable only for public installations or the very largest private aquaria.
Maintenance
Likely to prefer dim lighting and access to refuges in the form of driftwood, large rocks or lengths of plastic piping.
An enormous filtration system and dedicated regime of water changes should also be considered mandatory.
Water Conditions
Temperature: 19 – 29 °C
pH: 6.0 – 8.0
Hardness: 36 – 357 ppm
Diet
This species is a predator feeding primarily on crustaceans and smaller fishes, although there should be no need to use such live foods in captivity.
Smaller specimens will readily accept live or frozen bloodworm, Tubifex and most dried foods whereas adults can be offered earthworms, prawns/shrimp, mussels, strips of white fish flesh and larger sinking pellets.
Juveniles require a relatively high-protein diet whereas adults should not require feeding on a daily basis with 1-2 meals per week sufficient.
This species should never be fed the meat of mammals such as beef heart or chicken since some of the lipids and other organic compounds contained in these meats cannot be properly metabolised by fishes, causing excess fat deposition and even organ degeneration over the long term.
Behaviour and CompatibilityTop ↑
Likely to prove aggressively territorial and incompatible with other fishes in all but the largest public installations and even then may attack its tankmates.
It’s also one of few freshwater fishes that appear unafraid of humans meaning care must be exercised when performing maintenance.
Sexual Dimorphism
The male has an elongate genital papilla located anterior to the anal-fin.
Reproduction
Unrecorded in aquaria but this species is produced in commercial quantities via artificial treatment with hormones.
Under these conditions incubation has been observed to take 30-38 hours at 28°C/82.4°F with the fry initially measuring around 5 mm TL.
The yolk sac is fully-absorbed after a further 3 days with the larval stage ending after 4-8 days and post-larval stage 9-12 days.
After 30 days the juveniles were fully-developed with an average total length of 42 mm.
NotesTop ↑
Juvenile specimens are sometimes available in the aquarium trade although their purchase is strongly discouraged, and given its eventual size, aggressive nature and the fact it can live for several decades this species shouldn’t be considered a home aquarium subject in all but the most exceptional circumstances.
H. wyckioides can be told apart from most other congeners by the diagnostic characters given in Ng and Kottelat (2013) for the H. wyckii species group (see below) and from other group members except H. maydelli by possessing red (vs. grey) fins.
It can be distinguished from H. maydelli by having a grey-coloured (vs. green) body plus a greater dorsal to adipose distance (9.6–13.6 vs. 4.0–7.0 % SL).
Hemibagrus has been divided into a number of putative species groups which may or may not represent monophyletic assemblages, and following a major review by Ng and Kottelat (2013) H. wyckioides is included in the H. wyckii group.
Members of this assemblage can be told apart from other congeners by possession of a broad, highly-depressed head, 50-54 vertebrae and light-coloured principal rays in both upper and lower caudal-fin lobes.
Currently valid members are H. maydelli, H. microphthalmus, H. wyckii, and H. wyckioides.
The genus Hemibagrus currently contains 40 nominal species which are distributed east of the Godavari River system in India and south of the Changjiang (Yangtze) drainage in China, with Southeast Asia a particular centre of diversity.
Many species are important food fishes and some are cultured for the purpose, or for sport angling.
Hemibagrus has previously been considered synonymous with Mystus but following Ng and Kottelat (2013) members can be diagnosed by their moderate to large adult size and strongly-depressed head shape with the interorbital region normally flat or slighly convex.
The grouping also shares a number of characters with the genera Sperata and Bagrus, and these three can be separated from other bagrids by the following: mesethmoid highly depressed (vs. not highly depressed), prominent (vs. reduced) dorsoposterior laminar extension of the mesethmoid, the first infraorbital with (vs. lacking) a posterolateral spine, enlarged (vs. moderate or small) premaxilla, and the metapterygoid with a long, free posterior margin (vs. contacting quadrate and hyomandibular).
Hemibagrus can be told apart from Sperata by possession of a a relatively short and slender (vs. enlarged and elongate) interneural and by absence (vs. presence) of a concave surface in the posterior portion of the posttemporal in which lies a portion of the swimbladder.
It’s distinguished from Bagrus by possession of 7, very rarely 8 (vs. 8-10) soft dorsal-fin rays.
References
- Ratanatrivong, W., 2011 - Unpublished dissertation from the Graduate School of KU and KU Library: 34-51
Breeding Enhancement of Red-tail Catfish, Hemibagrus wyckioides (Fang and Chaux, 1949) by Using Cyclodextrin Complex. - Ferraris, C. J., Jr., 2007 - Zootaxa 1418: 1-628
Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. - Kottelat, M., 2001 - WHT Publications, Colombo: 1-198
Fishes of Laos. - Ng, H. H. and M. Kottelat, 2013 - The Raffles Bulletin of Zoology 61(1): 205-291
Revision of the Asian catfish genus Hemibagrus Bleeker, 1862 (Teleostei: Siluriformes: Bagridae). - Ng, H. H. and W. J. Rainboth, 1999 - The Raffles Bulletin of Zoology 47(2): 555-576
The bagrid catfish genus Hemibagrus (Teleostei: Siluriformes) in central Indochina with a new species from the Mekong River. - Rainboth, W. J., 1996 - Rome, FAO: 1-265
FAO species identification field guide for fishery purposes. Fishes of the Cambodian Mekong.
May 14th, 2014 at 8:08 pm
Does anyone know if Asian Red Tail Catfish are caught in China? I know that by the time the Mekong River gets to Thailand that they are in that stretch of the river.