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n the occasion of our 201st factsheet on ScotCat, eminent catfish author and enthusiast, Steven Granthas returned to pen a factsheet on one of the more overlooked catfish families. namely the South American family Trichomycteridae, which are commonly known as Parasitic Cats or by the local indigenous populations as "candiru". Over to Steve for his summary on the identification of Ituglanis amazonicus.

[画像:Ituglanis amazonicus]

Ituglanis amazonicus

I. amazonicus was described from “Cudajas, Brazil”, which could be Codajás, a municipality on the Amazon River. There is also a lake called Lago Badajós which used to be referred to as Lago Cudajas, and this is northwest of the municipality.

The specimen pictured here was one of a number that were imported from Rio Amazonas in Peru. The colour is a little faded due to it being photographed freshly imported. Galvis et al (2006), Mol (2012) and Le Bail, Keith and Planquette (2000) report it from Colombia (Amazon River), and Suriname and French Guyana respectively.

I originally thought they were I. laticeps (Kner, 1863) but after checking the description it states there were no markings on the fins of the type specimens. Datavo (2013, personal communication) indicated that the specimen has the right number of pectoral fin rays ( I + 5) for I. amazonicus and despite it not matching the colour and pattern given for that species in Datavo and Landim (2005), this specimen exhibits one of a variation of patterns in I. amazonicus. Some I. amazonicus have a very faded pattern with very few or small spots but the two patterns can be found within one population of the same species. Furthermore adult I. laticeps have the pattern shown here and it may be a junior synonym of I. amazonicus.

[画像:Ituglanis amazonicus = dorsal and caudal]

Ituglanis amazonicus - dorsal and caudal view

These are sometimes sold or seen as I. metae but that species has a more rounded caudal fin (albeit that us not always a reliable indicator as the fin can often be damaged) and also has one more pectoral fin ray (I + 6). I. guayaberensis (Dahl, 1960) also has a similar pattern but that species has even more pectoral fin rays (I + 8). Both I. metae and I. guayaberensis come from further north, in the Orinoco system in Colombia.

Despite their inclusion in the family commonly called ‘parasitic catfish’ so far reports of behaviour in aquariums are that they are peaceful towards other fish, and usually to each other. However, there has been one report of some specimens being attacked and ostracised from the group, with bite marks on the body and fins.

They like to hide during the daylight hours so something like a cave, thick plants, or wool mops should be provided.

They will sometimes feed in daylight hours but to make sure they are getting adequately fed, you should add some food after lights out. They will eat bloodworm, tubifex, and earthworms chopped into small pieces.

None

None

Trichomycterinae

South America:Amazon River basin and rivers of French Guiana and Surinam: Peru, Colombia, Brazil, Surinam and Guyana.

8.0cm. (3¼ins)

24-26°C (75-79°F)

Long, cylindrical body. Three pairs of barbels. Pectoral fin with I + 5 rays. Light greyish to light orange / brown base colour with greenish to brown spots of different sizes and distribution.

Generally peaceful but can sometimes fight amongst each other.

As yet unknown.

There are no proven external sexual differences, but females are probably more robust in the body.

Readily accepts all manner of live/frozen foods.

Barbels: Whisker-like structure on the heads of most catfish.
Caudal fin: The tail.
Pectoral fin: The paired fins just behind the head.
Synonym: Different name for the same fish.

Ituglanis: itys, ityos = circle in Greek; glanis = a fish that can eat the bait without touching the hook; a catfish in Greek.
amazonicus: From the Amazon River

Dahl, G., 1960. Nematognathous fishes collected during the Macarena Expedition 1959. Part I. Novedades Colombianas v. 1 (no. 5): 302-317.
Datovo, A. and M. I. Landim, 2005. Ituglanis macunaima, a new catfish from rio Araguaia basin, Brazil (Siluriformes, Trichomycteridae). Neotropical Ichthyology v. 3 (no. 4): 455-464.
Eigenmann, C. H., 1917. Descriptions of sixteen new species of Pygidiidae. Proceedings of the American Philosophical Society v. 56: 690-703.
Eschmeyer, W. N. (ed). Catalog of Fishes. California Academy of Sciences. (http://research.calacademy.org/research/ichthyology/catalog/fishcatmain.asp). Electronic version accessed 24 February 2013.
Galvis, G. et al, 2006. Peces del medio Amazonas – Region de Leticia. 1-546.
Kner, R. and F. Steindachner, 1864. Neue Gattungen und Arten von Fischen aus Central-Amerika; gesammelt von Prof. Moritz Wagner. Abhandlungen der Bayerische Akademie der Wissenschaften, Mathematisch-Physikalische Classe, München. v. 10 (1. abth.): 1-61, Pls. 1-6.
Le Bail, P.-Y. , P. Keith and P. Planquette, 2000. Atlas des poissons d'eau douce de Guyane. Tome 2 - fascicule II. Siluriformes. 1-307.
Mol, J.H.A., 2012. The Freshwater Fishes of Suriname. 1-889.
Morris, P.J., M.H. Sabaj, and C. Hoeflich. 2004. All Catfish Project Support Site. [WWW image database] URL https://acsi.acnatsci.org.
Steindachner, F., 1882. Beiträge zur Kenntniss der Flussfische Südamerikas. IV. [With 3 subtitles.]. Denkschriften der Kaiserlichen Akademie der Wissenschaften in Wien, Mathematisch-Naturwissenschaftliche Classe. v. 46 (1 Abth.) (in 1883): 1-44, Pls. 1-7.

Photo Credits

© Steven Grant @ Catfishes of the World