Page 2 of 3

Posted: Sun Jan 15, 2006 6:57 pm
by Emma Turner
Hi Andyroo,

We have found that certain families of fish seem to carry more mucus than others. When catching out fish for customers, some actually leave traces of mucus behind in the nets, koi are a good example of this.

Mucus however, can serve different purposes for different fish. For example, some cichlids produce mucus to feed their fry (i.e Discus) and this type is therefore unlikely to be toxic to other fish. Also, some of us on here have observed mucus in tanks containing Horse Faced Loaches (Acantopsis choirorhynchos). This can be found in the substrate and would appear to be linked with the fish's ability to burrow at high speed - the mucus almost acting like a lubricant.

This quote, from the book 'The Interpet Manual of Fish Health' (ISBN 0 86101 368 9), which I came across today, may also be of interest:
"Fish have an effective outer barrier in the form of scales and the layers of the dermis and epidermis, all of which provide some protection against disease organisms and physical damage. This outer barrier is further improved by a covering of mucus that contains a number of bactericides and fungicides. The mucous membrane is constantly being renewed, which also has the effect of sloughing off debris and dissuading the proliferation of external parasites."

Thank you for the kind comments about my loaches by the way. The biggest is about 11.5", there is a 10.5" one, several 8-9" ones, then a huge range of others right down to 3" (approx 45 Clowns in total).


Posted: Mon Jan 16, 2006 3:03 am
by ashdavid
andyroo wrote:Chiefkeith,

5-BIG fish predation. Sorry for being a bit of a neophyte, but i don't know what a dovii is... nasty no doubt. Cichlid? A gulper or more of a biter? I work in corals here, and what i've seen in fish predation on fireworm polichaetes (a major coral predator: they have nasty irritating defensive spines/hairs) is that if a fish can swallow it hole it will, but if it can't it won't even try. I reckon we're looking at something similar. The dovii couldn't swallow it... though it kept on trying, which kind of screws up my theory... maybe they're immune or a little dim... so eventually gave up with little (survivable) damage to the clown. But the jaguar and the perch did gulp it down in a single go... past the lips or taste buds or smell receptors which may have warded off disaster.
Very interesting that the perch has never eaten another clown and isn't so big on live food/feeders anymore. He may have learned something (?) Also of note is that this perch victim had only just been put into the tank. Defences take energy, so a loach not feeling stressed may not produce the toxins right away, thus the perch didn't feel it until afterwards, or not at all. How long were the loaches and jags/dovii together prior to consumption? With the puffers... i don't know, but that in nature puffers eat some nasty smelling and likely chemically acitve stuff like sponges, tunicates and whatever else they can catch and crunch up.

PS: Ashdavid... I hear you run a 2000gal set-up.... i've been hired to create a large, idiot-proof marine tank for a hotel. Any suggestions or contacts? I did this kind of work in Uni in Vancouver, but it's a different ballgame now...
My dovii is a chewer, he chews his food and spits it back out then repeats the process over and over until it is palitable enough to eat. He tried to eat the loach in the same way , but it seemed the spines were posing the biggest problem. BTW the loaches where in the tank long before the other fish and were tank mates for about 3 months before any aggression towards the loaches occured, then over a period of a year a loach here and there would fall prey to big cichlid.

The Jag also eats he food in the same manner. The perch on the other hand is a swallower, anything that dose not fit in its mouth is safe. He ate feeders after that incident ,but I have now successfuly weaned him onto prepared foods and even if a feeder is in the tank he will go for the prepared food as opposed to the feeder.


P.S. what do you want to know about with setting up a 2000g tank?

Posted: Mon Jan 16, 2006 1:23 pm
by andyroo

Have you got any photos on-line of your 2000gal set-up?
I'm producing a budget for the client, so my questions will have to do with costs in the initial and for ongoing maintenance. Feel free to contact me directly at this (profile) e-mail addy.


Thanks for your input. The LFS has a couple of red-tail cats (10-15cm) and i was thinking about investing... but if there's potential for my little clown to meet his maker, i'll put it off. I've actually read that these cats have irritant chemical in the slime of the red tail as well... out of interest.


Posted: Mon Jan 16, 2006 7:48 pm
by chefkeith

Posted: Tue Jan 17, 2006 9:05 pm
by ashdavid
Thanks chefkeith for posting those links. BTW my next tank is going to be reall,really big!!!

As for cost, I live in Japan, so I can't help you there, but filtration on big tanks and what material to use for construction can pose a problem if you want to discuss that?

Posted: Thu Jan 19, 2006 2:46 pm
by chefkeith
My view on chemical defenses is changing. By checking the other forums, it seems that most clowns are doing well with predator fish.

I’m starting to think that their razor sharp spines are not the only thing fending off most of these big fish. One guy said his clown "just swims right up to the Oscars and steals the food out of their mouths..."
That’s a confident loach.

I’m about 50/50 now. I've looked into this further.
Here are some interesting threads I've found- ... hp?t=91116 ... hp?t=44651 ... hp?t=72170 ... ge=2&pp=10 ... php?t=2636 ... php?t=6441

Posted: Thu Jan 19, 2006 6:42 pm
by Azmeaiel
Hi, I have also found that some clowns will line their favourite hideout with mucus. I kept 4 small clowns in a 60 gal a few years ago where they made their home in a fake castle. To my horror I put my hand inside one day and found a 3mm greyish mucus :x . needless to say it was cleaned out but was back again days later. repeated the process and it was back again. It was only when I found all the clowns wedged inside that I linked it to them. I guessed at the time they did this so as not to damage themselfs on the surface of the tight space in which they seem to prefer to hide. BTW it smelt nasty!

Posted: Mon Feb 11, 2008 7:21 am
by Dutch
Just a selfish bump so I won't loose the thread. :wink: (I'm sure most here who haven't read it will be interested.)
Still reading though but I'm on a timer.

Posted: Mon Feb 11, 2008 8:16 am
by shari2
I nominate chefkeith to lick one of his clowns...

<shari runs!>

Posted: Mon Feb 11, 2008 9:49 am
by helen nightingale
Dutch, thanks for bumping it, it is fascinating reading :D

Shari, i agree

Posted: Mon Feb 11, 2008 11:13 am
by Dutch
A very interesting read. Although I don't think I would get PhD-funding for it. :wink:

I did a quick search on publications on this and noticed that although there seems to be knowledge of different types of mucus secreting cells in the skin of fish, most papers on the subject are rather old.

I did like this introduction from a 1974 paper....
"We recently heard from Dr. H. Ids, an ichthyologist at Kitasato University, that he noticed the rapid death of small fishes, for example, the damselfish Chromic notatus, when they were placed in a container with coral-gobies Gobiodon spp. or scooped with a net which had been stained with the mucus ofcoral-gobies . This information led us to examine whether coral-gobies possess a skin toxin. Five species of Gobiodon collected at Ishigaki Island were found to have in the skin peculiar cells assumed to secrete a toxin which was positive in both taste and ichthyotoxicity tests."

Occurrence of a skin toxin in coral-gobies Gobiodon spp.
by Yoshiro Hashimoto and Kazuo Shiomi

Posted: Mon Feb 11, 2008 11:45 am
by mickthefish
on the subject of toxic substances in fish, certain cory's under stress of being transported exude a substance from near the gills/pectoral fins which Ian fuller captured in a photograph.
i can ask him if i can use the pic to show you all.


Posted: Mon Feb 11, 2008 11:52 am
by chefkeith
shari2 wrote:I nominate chefkeith to lick one of his clowns...

<shari runs!>

Posted: Mon Feb 11, 2008 4:11 pm
by andyroo
Chemical defenses in fish are not uncommon at all, sometimes emitted as in cowfish and boxfish, sometimes in slime/mucus coats as in moses sole and soapfish. Spines and retained/internal poisons i won't get into. Much less common in fresh water.

Re: funding, this would be a relatively easy chase. Contact the USAID and/or EU International Development offices in/for Indonesia/Borneo and ask about proposal generation, particular to pharmaceutical derivatives in/from fish. Can fit into value-added or aquacultural concepts for rural income generation. (note liberal use of buzz-words).
Look up how to write a good proposal on-line. That should be the first step, actually- right after we con ChefKeith to lick a clown loach and report back.

If you wait for funding to come to you, you will end up spending your life/career studying something that someone else thought was interesting or valuable, and that you will quickly realize actually sucks :)


Posted: Mon Feb 11, 2008 4:36 pm
by daspricey
This thread also begs the question,

Do other botiine loaches have toxic defence mechanisms?

BTW Andyroo, i know some people with a 20x6x4ft tank(Or something very similar)!


Ps, i have noticed mucus bits lying around the my tanks which hold weather loaches!