I have a white sucker that I got last summer. He has grown from 3 to about 6 inches since then. I have him in a planted, and pretty heavily stocked 55 gallon aquarium. Do these guys continue to grow, or will his growth be stunted in the aquarium?
These days I only go for fish that I know will stay small.

Your fish could double in size from the current size. I doubt he's stunted in a 55.

Growing to the size of the tank is an old wives tale but like many tales it was based on a little truth. Fish produce a growth pheremone that can help slow down or stunt the growth of others of their kind. This helps them compete against each other for food. This can be best seen in a tank of fry if you dont do regular water changes. The strongest fish grow faster bigger while the rest fall behind. Do more frequent water changes & they all progress more evenly. Now back in the early days of fish keeping, water changes werent done as regularly as we do now, so fish were getting stunted when kept in to small a tank. Regardless, for example, if you stick an sucker or goldfish in a 10 gallon tank, it will outgrow the tank.

Edited by exasperatus2002, 05 June 2010 - 10:20 AM.

Growing to the size of the tank is an old wives tale but like many tales it was based on a little truth. Fish produce a growth pheremone that can help slow down or stunt the growth of others of their kind. This helps them compete against each other for food. This can be best seen in a tank of fry if you dont do regular water changes. The strongest fish grow faster bigger while the rest fall behind. Do more frequent water changes & they all progress more evenly. Now back in the early days of fish keeping, water changes werent done as regularly as we do now, so fish were getting stunted when kept in to small a tank. Regardless, for example, if you stick an sucker or goldfish in a 10 gallon tank, it will outgrow the tank.

Yep, that's what I have read and basically believe. I just needed someone else to help me figure it out. I got a new 55g today that will house my shadow bass, pumpkinseed, black bullhead, and sucker.
Thanks!