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n the closing out of the year 2013 and the arrival of 2014 we have the last factsheet of the year and an insight into a species that over the many years of keeping various species of Catfish, I have yet to encounter the "Max Cat". Odd this as I have kept larger cats over the years including Sorobim lima, the larger varieties of Synodontis and the odd Hemibagrus species and also Chrysichthys nigrodigitatus which can get to a fair old size. I know some of the Hemibagrus species from the Bagridae family can get quite aggresive and Rhamdia quelen from the Heptapteridae family can also go down this route and be quite feisty.

Rhamdia quelen - adult from the Rio Purus

Rhamdia quelen used to be placed in the close family Pimelodidae. This is possibly the the most widespread of the numerous species of Rhamdia. There is even a blind cave-dwelling version from Trinidad and another described in 2005 as Rhamdia enfurnada, and is described from the Gruna do Enfurnado, Serra do amalho, southwestern Bahia State, middle São Francisco River basin. Troglobitic (cave dwelling) Rhamdia catfishes encompass at least eight taxa: R. quelen urichi (= Caecorhamdia urichi Norman, 1926), R. laticauda typhla Greenfield, Greenfield & Woods, 1982, R. reddelli Miller, 1984, R. zongolicensis Wilkens, 1993, R. macuspanensis Weber & Wilkens, 1998, R. laluchensis Weber, Allegrucci & Sbordoni, 2003, R. guasarensis DoNascimiento, Provenzano & Lundberg, 2004, from Venezuela, and the species described herein from Brazil. The form of R. quelen found in the Guacharo cave in Trinidad has been given the subspecies name of R. quelen urichi (Norman, 1926) Mees 1974. There is conflicting views that it should be a species in its own right as R. urichi, which was suggested by Silvergrip (1996). Another observation at the cave mouth said it was possible to observe all degrees of pigmentation and eye morphology, from pure quelen at the entrance to pure urichi at the end of the cave (Price and Endler, 1983)

There are at present 11 species of Rhamdia with 8 of these being in the Brazilian territory.

Rhamdia quelen - juvenile colours

Max Cat

Silurus quadrimaculatus, Pimelodus quelen, Pimelodus namdia, Pimelodus sebae, Rhamdia sebae, Heterobranchus sextentaculatus, Pimelodus hilarii, Rhamdia pentlandi, Pimelodus pentlandii, Rhamdia  hilarii, Pimelodus deppei, Pimelodus musculus, Pimelodus sellonis, Pimelodus stegelichii, Silurus sapipoca, Pimelenotus vilsoni, Rhamdia vilsoni, Rhamdia wilsoni, Pimelodus cinerascens, Rhamdia cinerascens, Rhamdia godmani, Pimelodus godmanni, Pimelodus micropterus, Pimelodus wuchereri, Rhamdia baronismuelleri, Pimelodus baronismuelleri, Pimelodus wagneri, Rhamdia wagneri, Rhamdia bransfordii, Pimelodus cuyabae, Pimelodus parahybae, Pimelodus queleni cuprea, Rhamdia guatemalensis oaxacae, Rhamdia oaxacae, Rhamdia depressa, Rhamdia guatemalensis depressa, Rhamdia barbata, Pimelodus boucardi, Rhamdia heteracantha, Rhamdia heteracanthus, Rhamdia nasuta, Rhamdia branneri, Rhamdia branneri voulezi, Rhamdia mounseyi, Rhamdia riojae, Rhamdia microps, Rhamdia pubescens, Silurus rivularis, Rhamdia micayi, Rhamdia quelen urichi, Caecorhamdia urichi, Caecorhamdella urichi, Rhamdia guatemalensis muriei, Rhamdia guatemalensis decolor, Rhamdia guatemalensis stygaea, Rhamdia saijaensis, Rhamdia sebae martyi, Rhamdia lehmanni, Rhamdia guatemalensis.

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Central and South America: Mexico to central Argentina. Type locality: Peru, Depto Loreto, right bank quebradita tributary to R. Samiria between Caño Pastos and Hamburgo.

35.0cm (15ins)

24-26°C (75-79°F)

Head moderately depressed, eyes small. Mouth wide and terminal. Maxillary barbels long, extending beyond dorsal fin. Pectoral spine stout, with serrations on posterior edge; adipose fin long and low.

Can be aggresive with one another which can lead to torn fins (see image above) but this trait may have something to do with the competition for food and the lack of hideing places.(Bichuette, M. E. and Trajano, E ; 2005). In the aquarium you should treat this species as you would any "Pim" and house them with tank mates that are the same size or larger and who occupy a different layer of the tank be it mid water or top. Provide plenty of hideing places if you intend to keep more than one individual. Not suitable to be housed with smaller species but should fit in with South American Cichlids and larger Characins in a spacious tank.

Not reported in the aquarium but breeder fish were subjected to induced reproduction through hypophysation using a crude common carp pituitary extract. Rhamdia quelen, has been studied and shownto be able to survive cold winters and grow fast in the warm summer (Barcellos, Kreutz, Quevedo, Fioreze, Cecirato, Soso, Fagundes, Conrad, Baldissera, Bruschi & Ritter 2004). Siluriformes, including R. quelen, are useful for aquaculture because of their texture, quality of flesh and high carcass yield (Ferreira, Nuner, Luz, Reynalte-Tataje, Esquivel & Restrepo 2001). The male's reproductive apparatus includes multi-lobed testicles and accessory organs for secretion and storage. Fertilization is external. Non-sticking demersal eggs (1.1 to 2.8 mm diameter) are laid down, hatching after about 48 hours at 22°C. Ten days later, the larvae weigh approximately 100 mg but growth is slow (0.5 to 1.15 g per day).

Not fussy so should be fed the usual aquarium foods such as flake, tablets, pellets, frozen and live food. Provide a varied diet.

Bichuette, M. E. and E. Trajano ; 2005. A new cave species of Rhamdia (Siluriformes: Heptapteridae) from Serra do Ramalho, northeastern Brazil, with notes on ecology and behavior. Neotropical Ichthyology, 3(4):587-595, 2005.
Bockmann, F.A. and G.M. Guazzelli, 2003. Heptapteridae (Heptapterids). p. 406-431. In R.E. Reis, S.O. Kullander and C.J. Ferraris, Jr. (eds.) Checklist of the Freshwater Fishes of South and Central America. Porto Alegre: EDIPUCRS, Brasil.
Catfish Association Great Britain; D.L./M.S. /7/79. Page 14.
Ferraris, C.J. Jr., 2007. Checklist of catfishes, recent and fossil (Osteichthyes: Siluriformes), and catalogue of siluriform primary types. Zootaxa 1418:1-628.
Froese, R. and D. Pauly. Editors. 2009. FishBase. World Wide Web electronic publication. www.fishbase.org, version (05/2009).
Marcelo BrunoVilaca Campos Gomes,Yuri Simoes Martins, Yoshimi Sato, Elizete Rizzo & Nilo Bazzoli. 2009. Early development of the silver catfish Rhamdia quelen (Quoy & Gaimard, 1824) (Pisces:Heptapteridae) fromthe Sa˜o Francisco River Basin, Brazil.
Proudlove G.S.; 2006. Subterranean Fishes of the World. An Account of the subterranean (hypogean) fishes described up to 2003 with a bibliography 1541-2004. International Society for Subterranean Biology Moulis. 300p.

Photo Credits

© Enrico Richter @