Jools wrote:Lophiobagrus is meant to be able to kill fish with it's mucus. Anyone know more about that? If they do I'll split this topic off and put it in Africa.
So it was said somewhere (Brichard, <Cîchlids and All the Other Fishes of Lake Tanganyika>), but I have not seen this myself or heard/read any other reports to this effect.
I think this may be a case of an extreme fright response mistakenly thought to be a natural response in the wild. I have seen instances where the mucus from captured <i>Clarias</i> have killed other fish kept with it in a bucket. It seemed that other ostariophysans such as barbs were particularly prone, probably because they might have become particularly vulnerable to this sort of shock, given the large amounts of "schreckstoff" (alarm substance) in the water.
Otherwise, I have never seen instances where the mucus produced by the skin of any catfish being fatal to other fishes.
That said, substances produced by the axillary pore (located just above the pectoral spine) in some catfishes can be definitely poisonous to other fishes. I once caught an <i>Acrochordonichthys</i> during a field trip and placed it in a plastic bag already half full of sisorids, loaches and fast-water cyprinids. The catfish didn't like being kept in the bag and proceeded to produce a milky white substance that was thicker than the usual mucus coating on catfishes (it had the consistency like thick snot). This proceeded to kill everything else in the bag in the space of minutes. By the time I realized what was happening, everything else in the bag was dead (which was no big loss to me since they were destined for the killing jar anyway).
