or our first factsheet of 2004 we spotlight on a species that could be deemed as one of the most dangerous freshwater catfish kept by aquarists. So as not to alarm unsuspecting keepers of this animal, the dangerous bit concerns the poison that can emanate from a gland on the pectoral fin spine and has been known to be fatal to some humans. If stung you should immerse the wound in very hot water so as to dissipate the poison and then get in touch with your local doctor.

Now that we have scared the living daylights out of you :-) we shall commence with a few facts on the Asian Stinging Catfish. This catfish for many years was in its own family, Heteropneustidae, and it is only very recently that it has been moved into the Clariidae family (Diogo, R., M. Chardon & P. Vandewalle, 2003) which many in the scientific community thought that is where it should be. There are differences between the two families listed below. This does mean now that the family Heteropneustidae is now invalid and is such retired.

Heteropneustidae: Short dorsal fin, two elongate pulmary sacs that run backwards from the gill through the muscles in the back.

Clariidae: Dorsal fin, large with many rays. Possess a much reduced air-bladder and their gills are stiffened to prevent their collapse when out of water and in a special part of the gill chamber are spongy arborecent (tree-like) organs growing from the upper ends of the gill arches.

Heteropneustes fossilis has the same attributes as the many Clariid species in that it can leave its chosen home and cross overland to an other body of standing water. This is helped by its body mucus which helps it from drying out

Depending on whose thoughts that you attain to, there is one other species in this family, Heteropneustes microps. The reason that I mention this is there is another theory that microps is a junior synonym of fossilis and they are one and the same fish. The for fraternity state that the difference is that H.fossilis has a separation (notch) between the caudal and anal fin and that H.microps has these two fins joined together. The against faction say that the the fusion of these two fins can be caused by injury and therefore are one and the same species (Rohan Pethiyagoda and Mohomed M. Bahir 1998).

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	Line drawing of Heteropneustes fossilis above showing the notch between the anal and caudal fins. Image of Heteropneustes microps left with fusion of the anal and caudal fins

All in all, not your usual catfish for the beginning hobbyist but something unusual for the experienced catfish keepers amongst us, and also a good challange for a breeding project. Give them a try.