Tilapia experiment

[duanes]

Picked up a group of Tilapia zillii juvies back in March, all about 1".
Put 6 together in a tank with 3 Nimbochromis, but put 1 zillii in a community tank (no other Tilapia) also put 1 Nimbochromis in the same tank.
Both tanks had same frequency and amount of water changes, received equal food rations.

after 5 months the Tilapia raised together (above) are @ 25% smaller than the one raised in a tank with no other Tilapia (below)

same results with the Nimbochromis

raised with other Nimbochromis above, no others of the same species in the tank below

Although the one tank has only 2 species, the bioload of the community was @ the same, it has 6 different species.

 

[LS2012]

Interesting outcome Duane. Are the single specimens male or female?

Sent from my Nexus 10 using MonsterAquariaNetwork App

 

[RD.]

Nimbo in the second pic is fat, not sure about larger, which suggests that it could easily compete with the other fish at feeding time.

 

[duanes]

The pic of the fat Nimbo is right after a feeding, the other before.
Not sure of the sexes of either Tilapia or Nimbos at this point, although I believe I see egg spots on both Nimbos anal fins. Could be I just happened to separate out males.
I also have a group of 15 Astatheros that have been growing up together for about a year, and all are very similar in size, my plan is to split them up in the next few weeks, and see what if anything in growth rate differences are apparent.

 

[cornbread_5]

you going to breed the zilli

 

[duanes]

If luck goes my way, and a pair forms, I would separate it out to get a spawn.
I find breeding of all cichlids to be my aim.

you going to breed the zilli

 

[5Spot Junkie]

Where did you pick the zilli up from? I'm interested in finding these. Very interesting outcome. I wonder why the single one is larger

 

[duanes]

The zillii were from a local aquarium society auction, might have been BAPed, think there were 9 fry in the bag for just a couple bucks.
They have been readily available in the Chicago/Milwaukee area for the last few years

My theory is the dominant fish produces hormones that may hold growth of others back in the small space of a tank.

 

[newworld]

For what it's worth I have found the zilli in the San Antonio river to be quite different in appearance and color, to your strain which is probably the same as the chicago....

 

[duanes]

I also believe mine are the same strain as chicago, it'd be interesting to see the difference from the San Antonio river zillii , do you have any pics?
The feral ones probably get all kinds of nutrients from algae, tank fish don't get.
I saw some schooling with young bass in a park in Sarasota Fl that looked similar to mine, they were in a small lake that had a very light colored sand bottom, could have been hybrids though. The ones in Aktun Ha in Mexico were darker.
Mine are still small, largest is only 4"-5"
Aktun Ha below, Tilapia show up about 4 minutes into the video.
https://www.youtube.com/watch?v=OT8GK9ZaJJo

For what it's worth I have found the zilli in the San Antonio river to be quite different in appearance and color, to your strain which is probably the same as the chicago....