gravid female Tilapia?

[shadowrunner762]

greetings all,

Thought i would start a new thread on this one.

I got the fish sorted out as best as i could yesterday, and i have my breeder set in the 55gal tank. the fish (5 females and 1 male) have been in there 24hours now and i noticed something after i got finished cleaning the sieve.

see the top fish in the photo:
IMG_0829.jpg

I noticed the bellies on the females are swollen in size almost double since i inserted them yesterday. the male has a normal sized abdomen so i am correct to assume eggs are developing in the females?

I have noticed some courtship activity, but the male hasn't really taken up residence in the flower pot i set in there. So far i have noted occasional body rubbing.

any info would be appreciated, the sights i have seen just give the general information on the overall process.

btw the male is 38gm and 5in long, and the females are 20-25gm and roughly 4in long.

be safe

[kellenw]

I think you're gonna have some spawning going on within a week or so.

[shadowrunner762]

Hi Kellen,
Good to hear from you, hope all is good on your side.

Some other items I have noted is the fish for lack of a better term "kiss" there is a open jaw touching I noted, with usually the female darting away.

I have been observing the male/females in terms of physical make up it looks if the females have a more conical mouth and the male slopes down in a straight arc from his top fin to his mouth.

Some sights have talked about "pruning" the upper lip of the male for brood protection, any thoughts on that?

Thanks again

[kellenw]

Hey bud! Good observations. Those are all correct. The "kissing" behavior is common between male and female tilapia. It is thought to be a method the female tilapia uses to "size up" the male and make sure he's a worthy partner. This is pre-spawn behavior, so is very encouraging.

The anatomy observations are spot on as well. Some strains display this far more clearly than others though, and sometimes a female or two will just completely throw you off too (they'll have a lot of "male" physical characteristics).

Cutting the top lip off is a method of absolute last resort for me. I don't do it as a regular practice, even though I have had to do it a few times. Typically, I will just cull out any overly aggressive males. I find that if you provide enough structure in the tanks (essentially, hiding places), aggression is rarely a problem except on very rare occasion. I clean and process thousands of fish every year and tag and fin clip tens of thousands, but for some reason lip cutting really bothers me.

Make sure to keep me updated on your progress! Email or call me if you need anything.

[shadowrunner762]

Hey Kellen,

Figure you might be able to answer this. I noticed that the "male" in the group is hogging the food, I am feeding accross the tank to break up the the concentration of feed. The male is chasing the females around alot, to the point there looking to find hiding spots. Is it normal pre-spawning activity? Or is the male being overly aggressive here?

Another item I noted is that the females will do the circular nose to tail dance. Is that only done with male/females, or can any of them do it? Reason I ask is with further observation, I might clear up the issue if I mis-identified another possible male in the system. I have one fish that is questionable lol..

Thanks again

[kellenw]

The males will often hog the food, but after they go through a few spawn cycles they usually settle down. If there is another male in the tank, this bad behavior is amplified greatly.

All of the fish will do the "dance" regardless of gender. It is typically a pre-spawn activity. You'll see this commonly occur with male v male and male v female, but much less often with female v female. You may be right, you may have another male in the tank, who is just not displaying dominance.

[shadowrunner762]

HI all,

The wife and i decided to take a second look at the fish today since i was doing a water change. When i did the original look at the fish she had helped me out since i figured that 2 sets of eyes were better than one..

It turned out that with the photos we were looking at, the wife didn't realize that she was looking at the anul cavity instead of tho ovid ducts. lol... which with the new pictures that showed the fish oriented to the sexing, i got the "hmmmm" from her.

we went through all 6 fish... again.. and matched it to the new pics we had and we came the collective decision:
1) we have 6 fish in the cage
2) the wife thinks they "poop" alot.

lol...

so the consensus is to leave the fish in there since we couldn't see any difference now that we had a better pix, and let the filter system adjust to the new fish load. I think ill let them grow another 1" or so and try again. I did add several more 90degree elbows in the tank to give some more hide outs if the fish needed them till we sort this out lol...

If someone has a better way to do this visually i am all ears.. lol

be safe.

[kellenw]

Hehehe.... It's understandable. They are not the easiest to sex.

[shadowrunner762]

greetings all,

Was busy staring at the fish tonight in the breeder tank, and i think i might of noticed something of significance.
I noticed after i fed the fish that some of the fish (4 for sure) were doing the usual heavy displays of:
mouth sizing,
gill flaring,
and rubbing.

But tonight i noticed,
(sorry unable to get anyone to sit still long enough for photo lol)
between the anus and the tail fin:
a small 1mm max cone that protruded on the fish, during display activity.
I noticed that a definite convex arc, away from spine, from the anus past the sliver cone to the fin.

On 2 of them, no sliver/cone, and a slight concaveness (sorry no other way to explain it) from anus to fin, towards the the spine.

I think i might be closer to identifying the males to females.

anyone have any thoughts?

thanks