Backyard Aquaponics
A place to discuss aquaponics

I recently set up a 55 gallon breeding tank and placed two of my smaller tilapia in it. The tilapia were very pale, almost white.

I put a large flower pot in each end of the tank, facing away from one another.

A few days later, I placed my largest tilapia in the tank. He was quiet for a day. I noticed that the water was in the 70's and put in a heater. The water temp is now in the lower 80's.

The large tilapia (I assume he's a male) is now constantly badgering one of the smaller ones. This tilapia has almost completely changed color. It is now gray with almost black striping. Is this stress? Is is something to do with mating?

Thanks.

My bluegill change colors all the time.

I noticed this sort of thing before myself. Not sure what causes it. I know the tilapia I have raised seemed to get more pigment as they matured. I have also noticed that bluegill, largemouth bass and channel catifsh all will be lighter (almost white) if they are in light colored muddy water. On the flip side they become much darker in clearer or tannin stained black water (like Florida in some spots). I would think it is some sort of a defense mechanism. I think it is quite normal.

I am new but hope my observations help.

Badgering from a fish that is dark gray color is most likely a female about to release fry. Check her mouth. Does she hold it clamped almost shut with her throat puffed out? Has it been about 2 weeks since you tried to invoke spawning?

Or is it the smaller one that is gray and being badgered? In this case, she doesn't want to put out and the male wants her to. Watch to make sure he doesn't kill her.

My tilapia change color all the time. The males colors intensify when they are excited or fighting. The females seem to change color in response to sunlight, or stress. A couple of my females turned almost black before they died -- I'm assuming the cause of death was harrassment by a male or an aggressive female.

I'm learning so much and having so much fun with my aquariums that I almost hate to put my fish in a big tank.

Janet,

What can this poor guy do to get her in the mood? He can't exactly do the dishes. How can I help?

The one fish I had that for some reason was cut open (probably got stuck in the drain then hurt itself getting free) was very stripey and dark. This is what a stressed-out tilapia looks like:

That's what I have then, one stressed out tilapia. It looks exactly like that.

Thanks.

Yep, if it has scales missing, slime coat ugly, fins tattered -- it is probably under stress. If possible, give it some alone time in some clean water that's about 75F to 85F with some salt. A bucket with an airstone might do in a pinch.

If I could figure out how to get the gals in the mood, I'd have lots of fry. The most success I've had is to keep guys and gals separate and then when the gal is plump, introduce them.

....oh, and make sure that they guy is really a guy.

Hi EMS, this thing can be related to retin opacity too, did they have white eyes before they died, in fact the body colour reacts to light intensity or stress or to social behaviour as said previously, sometimes when the fish loose vision the body reacts as if it was pitch black so adapt there colour to the environnement.
If there eyes were white, it is usually old fish or an excess or a lack of vitamin C, most often the fish food looses the vitamins well before it is eaten, specially fish farming fish food.

And concerning spawning most fish react to rain fall in the wild, the idea is to create a fake rain fall by changing water, and putting 4°C colder rain water in the tank for a few days and let the temp slowly increase to normal.

Hope this helps but fish spawning is not easy because a lot of factors occur in the wild that are not easy to reproduce, fresh live food, water temp, hardness, day light lenght, genetic, barometric pressure...

Janet: How's your new job? I hope its all right and not to stressful

New job is going OK. I still have a lot to learn, but it's coming along.

Janet, what do you mean here by "plump"? They all look the same to me in that respect. Two are much larger, I am assuming they are the males. Non seem to be more slim or plump than the others.

The fish that was harassing the smaller one is huge. Can I safely assume he's a male?

Rand

"Plump" in the belly region--and that's before chow time. You can also try inspecting the private parts. Right as the female is getting ready to spawn, she "blushes" around her genital opening.

Given that your fish are close to the same age, I'd say its a good bet that the largest ones are male--especially if they are aggressive, defending territory, and splaying out their fins.

Your fish are probably 2/3 male since I was culling for size. I would bet on the smallest 1/3 being female.

Plump is a good way to describe the females that are ready to spawn. -- They get a bulge right in front of their anal fin and sometimes their "port" swells up and sticks out.