Tank dynamics for the past three months - changed again today...

My 55 gallon which contains a large dominant longear, a Hybrid (red ear/green), a smaller longear and a blue gill has been slowly changing dynamics over these past three months. The large dominant longear has been the king fish in the center of the tank since I stocked it back in late September although he was only about 4 inches long then. Today he is over 6 inches long. The hybrid is currently about 7 inches long.

Month 1.5:
All other fish except him, at first were hiders staying mostly back behind the log or rocks and the dominant kept them there forcefully. They ventured out only at feeding time and it was difficult in ensuring all got proper amounts to eat. They all quickly took up protective positions after the feeding. Then after about a month and a half the hybrid started inching out from the log in the back and staking new positions. Eventually, he left the safety of the log entirely and staked a position central behind some plants. When the dominant longear challenged him, which was frequently, he did non-dominant posturing but refused to go back to the log. Eventually, he started to posture against the dominant a little when challenge. He continued to work his way to the right side to the right side of the tank till he was right side and in front. The dominant longear still challenges him a dozen times a day but the hybrid now stands his ground and they frequently furiously chase each other in a tight circle. At feeding the hybrid is now the first one to come front and center and get food.

Month 2:
The bluegill which is now about 4.5 inches long, probably smaller because it was difficult for him to get food during the feeding period at first also initially maintained a position completely behind the log coming out only at feeding time up to the second month. After the hybrid moved out from the log, the bluegill has slowly been working his way out and eventually I found him half the time behind the log and alternately to the right behind some pipes. This further changed over time to passing slowly back and forth between the two positions and then to one of spending half the time out in the plants at the back of the tank. He is challenged frequently by the longear but now no longer dashes to safety but rather slowly just moves off stage to what ever stops the aggressive behavior. Now, he immediately comes to the front at feeding time in the morning and joins the longear and the hybrid in the feeding fray and no longer hides as much as he used too.

Month 3:
The smaller longear, now about 5 inches, has always been the shyest. Initially, he always stayed behind the log and rarely got his share of food in the first month, never coming out to join the gang at feeding time. I had to work at it to make sure he got anything. Then, after about a month, he would pop his head above the log at feeding time in the morning and wait till the dominant longear was distracted and make a mad dash to the food and then back to behind the log. At about two months, he would pop out entirely from his hiding position which is on the extreme left side of the tank and wait for food opportunities during feeding times. This would bug the hell out of the dominant longear and he would chase him back to behind the log at every opportunity he had. After another few weeks he actually started coming all the way to the front and joined the gang in the initial feeding fray. He did not stay long and the dominant longear was aggressive but the smaller longear did not dash back quite as fast as he used to to his side of the tank.

This continued till this morning - about three months from capture. Today, I am feeding the fish and the smaller longear (about 5 inches) comes out to the front and joins the fray. The dominant longear makes a move to chase the smaller one back to the log and the smaller one turns his side to the dominant longear but does not budge his position. They were side to side for quite a long time fin waving, arching their body with some pushing but the smaller one stood his ground. I swear it looked like the dominant longear actually looked startled and perplexed. After feeding, the smaller one went back behind the log but I am sensing that he will soon come out and stake a claim at the left side of the tank, no longer hiding behind the log, which will be as far as the dominant longear will then be able to move him.


I find this all greatly entertaining and instructional. There is no doubt that these fish have a personality and think things through. I am glad I finally put the native tank together.

Usil

Edited by Usil, 16 December 2011 - 04:14 PM.

The stocking arrangements in my tanks are somewhat different from yours so it's quite interesting for me to read about the dynamics in your tank. Heck, it'd be interesting even if they were stocked identically. It's just plain fun to discuss fish. With the enjoyment you're getting with this tank I'm surprised you're not looking into another one yet with different species.

Very entertaining reading,
Thanks for posting.

Steve.