It's a given here that 80% of all research funding applications are turned down, and PhD proposals take a year to get through.
I still have a lot of orientation to do. I've tried to come up with projects for my masters traineeship, but even that has been difficult.
Go! ChefKeith Go!
sterbai and gossei are one of the worst of the cory's for doing this, what we have found in some way it depletes the oxygen in the water and will kill all the other occupants of the bag/tank .
this pic was given courtesy of Ian Fuller & CorydorasWorld.com
Has this been tested by actually measuring O2 levels in the water and in the mucus?...it depletes the oxygen in the water...
Is the Cory hurt or sick?
Has it been determined that this stuff is actually toxic? Or do the other fish die of low oxygen?
If this mucus is specific to the gills, perhaps it does have something that attracts oxygen and helps the Cory to get oxygen from the water; its killing ability is incidental or secondary. I would think in a flowing stream it would get diluted too fast to do the fish much good as defense, and in an enclosed body of water it could kill the fish that created it, once it was released...
If it kills by being toxic but the Cory is immune to the toxin, then the oxygen depleting might be secondary.
Happy fish keeping!
the female in the pic did die the male survived but only just.
these were perfectly healthy fish before they were caught and put in the show tank,
by the looks Diana this pic was taken at the show venue.
but this mucus/fluid is only done by a certain number of corys,
the two mention with the pic are i'd say the worst of the bunch.
a freind took all his breeders to an auction to get shut of them as well as their off-spring, the adults were dead or near to death when they were pulled out of the poly box but none of the youngsters were affected with the stress the adults shown.
all the fish were individually bagged.
i'll ask Ian if anyones tried to see what this thing coming out of the gills is.
The gills, and any epidermal epithelium, can secrete mucus and stress can cause excess secretion.
I haven't read it yet, but I have a paper called 'Function of fish mucus' from 1994. It's old, but if I can spare the time I'll look it through.
I think Diana has a very keen observation. The natural situation vs. the bag they are transported in, or the aquarium they live in. There's a big difference there.
What are the major predators of Bornean creeks/rivers?
Reptiles might be found in deeper water, or shallow, sun-lit or shade. I do not think that taste or smell plays much of a role in dictating to reptiles what to eat, either. (I might be all wet, here, it would not be the first time)
Predatory fish might be found in waters where there is more cover for them to hide, but not all predators hunt from ambush.
Of what benefit is a substance that can kill the fish that produced it?
Well, if it only killed under conditions that are not found in nature (Confined to a tank or bag, poor water flow, recirculated water of limited volume...) then the killing is a secondary or lower ranking effect, not likely to occur often enough in nature to become an evolutionary force. Hmm...
If, for some reason wild fish were confined to a small pool (Dry season...Small enough water volume that this toxin might kill) then what is the potential survival rate, anyway? Isn't such a pool drying up? Wouldn't so few fish survive that the death-by-drying vs death-by-own-toxin is not likely to be a factor. The fish is dead. That it could not tolerate the toxin that it produced in such a confined location is not important. It cannot reproduce. If it was more tolerant of the toxin, it would still be dead, and still cannot pass on tolerant genes.
The same species of fish, in a larger body of water that can produce a bad tasting toxin might be spat out by a predator, or might make the predator so sick that the predator leaves others of the species alone. The fact that the bad tasting toxin might have killed the fish in another setting is immaterial. The toxin has done its job of protecting the species. That predatory mammal will now be leery of spotted catfish, and will teach its young that spotted cats taste bad.
Happy fish keeping!
In the CL, the mucus chemical appears to be a stress-reaction: not produced in happy animals, thus they can be eaten, but produced in animals chronically exposed to predation or related stresses, such as in a predatory tank or in a bag. Remember how your other clowns freak-out when one is caught in the filter- there's a chemical signal produced at least. Do other loach spp do the same when a school mate is damaged/killed? Not that i've seen, nor have i seen this reaction in other families/fish.
Just a thought, but these two species know each other. Arowana and Clown Loaches both come from Borneo and Sumatra. Maybe an instinctive reaction?andyroo wrote: I'd watch the arawana go in for a taste, then back
off at the last moment.
It doesn't explain the behavior of the other fish yet, but I like that there is a relationship between these two species.
Who is online
Users browsing this forum: No registered users and 3 guests