Aggro Silver Dollars?

[Sumpin'fishy]

I have 4 Silver Dollars around 2" length each. They each are slightly different size, though. This question is regarding the second largest SD is getting pretty aggressive with the others, especially the largest one. They have been circling each other frequently today and "vibrating" or "twiching" while circling, then lunging at each other. No damage is really taking place (pretty blunt noses!) but they look to be serious about it. The aggro one is constantly chasing one of the others around, if not the largest.

My best guess is that he is trying to make a play for dominance. Maybe the largest is female and the aggro one is male. What do you guys and gals think? I have never noticed this aggro behavior before today in them.....normally they shoal very peacefully. Is this common?

There is a 6" Blackbelt cichlid in the tank with them and they generally all get along well. Just don't touch his food!! He's not bothering them or vice versa in this situation.

 

[OrionGirl]

Could it be courting behavior? I'm not that familiar with silver dollars, but the behavior is similar to courting behavior seen in many other fish.

On a side note, my recent trip to the LFS included overhearing the following exchange:

Customer: Will those red hook silver dollars be okay with aggressive fish?
LFS: Depends on--what are you putting them in with?
Customer: I got a big green terrier.

I about died--had to run out before chastising him for dyeing a dog green and keeping it in a tank.

 

[ChilDawg]

You mean that that's not what a dogfish is???

 

[Sumpin'fishy]

That's a classic!

I have had good response from adding my SD's.....they are pretty quick and agile (though they don't look it!) and are able to get out of the way when lunged at by my Blackbelt. They also work well as a team and have "learned" how to pick up food off the floor from the same spot as the BB. One of them makes a slow move in, the BB usually lunges at him to get him away from the food, and the others take quick darts into the food zone and grab a quick bite! Then they repeat it in different order.

Another thing that helps IMO, is having 4 SD's since they are so small the bigger fish get confused when chasing them.....they also "school" together further confusing the aggro fish! They even did well in the tank before my Jack Dempsey died from uncertain reasons. He was at least 6" and the dominant one. No problems with SD's getting hurt! GOOD DITHERS!!!