Common or Comet Goldfish?

[Liumchen]

And does it make a difference in terms of care?

I got him as a gift from my housemate's six year old son just a couple of days ago. He's currently sharing a tank with some tropical fish, including a few Zebra danios, bloodfin tetras, and juvenile Chinese Algae Eaters. They will soon be upgraded to a much larger tank (60 gallon, with heater).

This brings me to my third and final question. If I keep the heater on a low setting (Roughly 22C/72F, give or take, with the goal of overlapping the desired temperatures for tropical fish and cold water fish) can they stay together?

The tank they are in now is a 10 gallon unheated, with the surrounding room temperature hovering around 25C/77F, with minute dips at night. All fish are healthy and active.

Thanks for your help!

 

[Autumnsky]

The tail looks longer than a common GF.

The Comet can get to 12 inches long in the body providing they are kept in good conditions. They are NOT a fish to be kept with Chinese Algae Eaters /CAE.

The CAE will mature and generally get aggressive and even more problematic, they tend to favor sucking on the mucus of fish particularly as GF have a nice coating of it.

There are fish which will do fine in cooler tank environments, White Cloud Mountain Minnows, (could be food with a mature GF in a tank environment), Platy, Endlers, the Zebra Danios and your Bloodfin Tetras too. Will need a minimum 4' / 1.25M tank.

The Comet is not a good companion for slower eating GF the fat bodied ones - especially like Telescope eyes.