Lophiobagrus mucus story & factoids...

[Sid Guppy]

First off; what HH -Siluris- describes about his Asian cat, -killing the other inhabitants of the collecting bag with slime- is documented by Pierre Brichard:
In his "Cichlids and all the other fishes of Lake Tanganyika"-book he writes about Lophiobagrus cyclurus:
"a single Lophiobagrus cyclurus placed in a jar, proceeded to secrete such an amount of mucus, that the whole jar was filled with it, and the consistency was that of gelatine; like the liquid had changed into rubber or something"
This book is for the Tanganyikan fishenthousiast, what Burgess big Atlas is for the catfish-lover. A bit outdated on nomenclature and some facts; but until now, still the most complete work on these fish. (after that one, only cichlid-books have been written on Lake Tanganyikan fish). The only other written account on non-cichlid fishes of Lake Tang is http://www.tanganyika.netliberte.org but you need to know French (wich I do; a bit).

Other Lophiobagrus mucus -related facts, from my own experience:
-about the mucus: I once had an adult pair in a 100 liter tank. Because the male was bent on killing the female; ripping off her fins and skin; I had them separated by a perspex pane, placed somewhat in the center. At one time, some other fish were residing in that tank, because I had to use it as a quarantaine-tank annex isolation tank as well (I didn't have my current options; many tanks). The tank was decorated with some rocky caves and a riversand 1" bottom.
Once I bought 4 Phyllonemus typus; I put them with the female, who was much more docile. After one time however I saw them having skin problems, like burns. They were also 'floating' in the water, and showing off signs of imbalancy. I took them from that tank, and put them with the other Tangfish, despite not having been quarantained for 4 weeks. They recuperated pretty fast, and have been fine. Strange thing however; since the resided in a likewise tank in the LFS with maybe 40 Lophiobagrus (small ones); and looked fine when I bought them.
At an other occasion I had to isolate a male Ophtalmotilapia heterodonta -Featherfin-, to give the females some rest, and put him in with the Lophio's in the same tank.
He started to behave stressed after a few days, and one morning floated dead in that tank. There wasn't a single scale missing, but looking at the state of gills and his wide open mouth; he obviously had suffocated to death in the night....? His colors were more virulent than they ever were when he was alive! I used carbon on that tank, the whole time it was used.

[Silurus]

Which brings me back to the point that this may not be the result of regular skin mucus secretion, but rather, something from the axillary pore (doradids and pangasiids are known to secrete a milky white substance from this pore as well, that AFAIK, has not been reported to be posionous to other fishes).
Since there are a fairly large series of three or four different <i>Lophiobagrus</i> species in the collection here, I'll examine some on Monday to see if this pore is especially well developed.

[Dinyar]

FWIW, I've had L. cyclurus shipped to me with multiple fish in a plastic bag. The first time, there were two to a bag and they were in the bag for about 36 hours. Both survived. The second time, there were three to a bag, they were in the bag for 72 hours(!), one died. I suspect it died because 72 hours in the bag was too long. There was a distinct ammonia smell when I opened the bag.

Silurus' schreckstoff hypothesis is an interesting one. I have had knowledgeable importers tell me the only time they recommend adding tranquilizers to shipping bags is when they shipping multiple small to medium ostariophysans in one bag.

The report of the mucoid substance released from the "axillary pore" is also very interesting and is something I've never heard of before. Do all catfish have this? Other orders? What is its function? Can it be seen with the naked eye or a loupe? If so, where should we look and what should we be looking for?

Dinyar

[Sid Guppy]

Currently I got three subadult Lophio's at home, and one baby (from a spawn made by two of the subadults). One of the subadults (the 'leftover') has a more stubby shape and a clear edge on the tailfin.(like the tailfin of a Leaffish, or the edge of the tail of Ctenopoma acutirostre -Giant Bushfish)
The adult aggressive Lophio's from my post (wich I traded away) had this too.
According to the descriptions, L cyclurus should have dark edges, but I never saw that. Only a slimmer fish in wich the coloration goes to the edge of the fins and a stubbier one with clear tailfin edge.
Know anything about this? subspecies or so?

[Silurus]

It seems that not all catfish have this pore (or maybe they are not readily visible in some catfish groups). The pore is normally located just above the base of the pectoral spine behind the cleithral (humeral) proces. Very obvious in some catfishes like pangasiids. And also very obvious in recently-preserved <i>Acrochordonichthys</i>, because there is usually a plug of the congealed milky-white substance there !

[Dinyar]

Currently I got three subadult Lophio's at home, and one baby (from a spawn made by two of the subadults). One of the subadults (the 'leftover') has a more stubby shape and a clear edge on the tailfin.(like the tailfin of a Leaffish, or the edge of the tail of Ctenopoma acutirostre -Giant Bushfish)
The adult aggressive Lophio's from my post (wich I traded away) had this too.
According to the descriptions, L cyclurus should have dark edges, but I never saw that. Only a slimmer fish in wich the coloration goes to the edge of the fins and a stubbier one with clear tailfin edge.
Know anything about this? subspecies or so?

According to Eccles, <Field Guide to the Freshwater Fishes of Tanzania>, Lophiobagrus asperispinis has both a stubbier shape than L. cyclurus AND clear fins. I also notice that one of my Lophiobagrus has a lighter color and clear edges to the fins. Can't say for sure whether it's stubbier than the others.

Dinyar

[Silurus]

I looked at both <i>L. cyclurus</i> and <i>L. aquilus</i> today and both species have a very large axillary pore. In fact, the pore is still covered by a plug of congealed mucus in many specimens.
It is also hypothesized on pg. 20 of Bailey & Stewart (1984) that the secretion comes from the axillary pore, who noted that the glands associated with the pore were more greatly enlarged than those of <i>Chrysichthys</i>.
So, good evidence that it is the axillary pore secretion and not the mucus on the skin that is the culprit.

[Dinyar]

Currently I got three subadult Lophio's at home, and one baby (from a spawn made by two of the subadults). One of the subadults (the 'leftover') has a more stubby shape and a clear edge on the tailfin.(like the tailfin of a Leaffish, or the edge of the tail of Ctenopoma acutirostre -Giant Bushfish)
The adult aggressive Lophio's from my post (wich I traded away) had this too.
According to the descriptions, L cyclurus should have dark edges, but I never saw that. Only a slimmer fish in wich the coloration goes to the edge of the fins and a stubbier one with clear tailfin edge.
Know anything about this? subspecies or so?

SG,

I wondered about this and checked my own fish, all of which had clear edges on the caudal and dorsal fin. As you say, it is sometimes claimed (e.g., Eccles, <Field Guide to the FW Fishes of Tanzania>, FAO) that L. cyclurus has deep black edging to the fins.

Yesterday I received a copy of "Bagrid Catfishes of L. Tanganyika..." (thanks, Santa!), which presented original descriptions of three new Lophiobagrus species (L. cyclurus had been described earlier). Nice illustrations of all four Lophiobagrus species, including L. cyclurus. The illustration and accompanying text clearly shows/says that L. cyclurus has CLEAR fin edges.

Cheers,
Dinyar

[Sid Guppy]

Wow!
this means we've bred another species!
tanx
The "dark edges" description I've got from Scotcats' factsheet on Lophiobagrus; but I might have already mentioned it....

The weird thing however, is the very different character. Whereas the L cyclurus that I've had, where VERY aggressive to each other (in a 130G tank!) up to the point of one getting killed by it's conspifics; the "other one" without the clear edges; are very nice, as Lophio's go.
My first L cyclurus were an adult couple (male 10, female 8 cm big). That male was always ripping off mucus and skin from the female; chasing her through the entire 2-meters tank etc. I had to separate them; when I tried to breed them. My second couple were youngsters, about 5 cm (male) and 4 cm (female). They were the replacements in the big tank, but after a few months it was clear, that the female was chased again, and rarely ate (she grew 1 cm in 8 months, whereas the male grew to 8 cm). I tried to couple that big male with the older, bigger female; wich was a mistake; setting all four of them in a tank with ample hiding place (more numbers; spreading aggression) was an even bigger; I lost that male. He had his tail, his adipose and half of his skin ripped off, and died. After that, I was so sick and tired of them, I sold the male to a Belgian fishkeeper, and the female to a different person.
The "edge-less" Lophio's were a young couple residing in a friends' tank. I gave him my tiny female (the last Lophio I had) as well.
But after I helped him, with his tank setup and care we found a few babies! They are obvious pure 'edge-less' Lophio's as we found both parents with their young under a rock. We could only catch a few; his tank had diseases in it, and only one baby Lophio survived. (He doesn't breed his fish on purpose; just has 1 tank. It's me who raises the youngsters of many fish)
Now he quit with Tangs, and al his Lophio's are mine again. They're digging another home, right now! The true cyclurus female is tolerated and miraculously, behaves truly nice. Baby #1 is growing like anything (after a bad start).
If anything happens again, I'll keep it posted.l