Read this article from a Fergus Falls Minnesota newspaper.

 

How fast do fish actually grow?

> In Otter Tail County [MN], fish typically only grow during 3 months of the year, Jun, July and Aug. Once water temps begin to decline in Sep, fish growth stops and excess calories are preserved as fat for the long winter ahead instead of continued growth. In the spring, energy is spent on spawning instead of growth. With such a short window of opportunity for fish to grow, many anglers are surprised to find out how long it takes to produce a “keeper” sized fish.   > The type of lake a fish lives in also determines how fast it may grow. Shallow, fertile bodies of water tend to warm quicker in the spring and have more productive food chains. Growth rates tend to be faster in these types of lakes. Deep, less fertile lakes take longer to warm in the spring and have less productive food chains, which leads to slower growth rates.   Now, for the more-popular species in MN’s Otter Tail County. Keep in mind that most gamefish species sexually mature at about the same age as anglers consider them keepers: > Walleye: Typically about 6″ in length after their first year of growth. On average, a 14-15″ walleye (1 lb) is 4-5 yrs of age. A 20″ walleye (3 lbs) is usually 7-8 yrs of age. Walleyes in excess of 20 yrs of age have been documented in Otter Tail County.   > Bluegills: In most lakes, bluegills don’t reach a “keeper” size of 7-8″ until they’re 6-8 yrs of age.   > Black crappies: Most anglers consider a 10″ crappie a “keeper” and on average, a fish that long would be 5-6 yrs of age.   > Bass: A 14-15″ bass (2 lbs) is on average 5-6 yrs of age. A 20″ bass (5 lbs) is approximately 10-12 yrs of age.   > Northern pike: Typically reach an average length of 25″ (4 lbs) at 4-5 yrs of age. A 34″ pike (10 lbs) is 8-10 yrs of age.   > Muskies: Can reach lengths of 50″ or more, which typically takes 15-20 yrs.   > Lake sturgeon: Don’t sexually mature until they’re 20-25 yrs of age, and will have attained a length of 50-60″ or greater at that point.

A biologist at a BASS Elite event in 2015 told me that it takes about 10 years for a bass to reach 20 inches/5 pounds here in the north.

 

Pretty astonishing how long it takes for some of these fish to reach a specific size here. Its obvious that we need to more so abide by selective, restricted harvest. Over harvesting of certain species like large bluegills has been well documented.

I think this is close 

A-Jay

Always interesting how different climates impact fish growth and lifecycle.

 

In Florida I always hear a largemouth will grow 10 inches the first year, then between a half pound to two pounds a year depending on male/female and available food.

 

Not sure if this is science based or dock talk, but I’ve heard the average 5 pound Florida bass is a 4 year old female, with 6 years being the top of the average life expectancy.

Interesting information.  I've always wonders how fast different species of fish grow, and how climate affects them.   

 

 

In the South it takes about 4 years for bass to reach 5 lbs, but they only live to be about

8 years old. The World Record smallmouth was approximately 13 years old which made

it unique. 

Bass are Bass buy very different between species. Smallmouth, Largemouth and Spotted bass grow at different rate and live different lifespans.

Old oldest “Bass” recorded is a Smallmouth at 23 years, it was a smaller male as I recall. 

Florida strain Largemouth grow very fast but only live 8 to 10 years in Florida, 12 to 15 years in cooler California reservoirs.

It’s all about water temperatures for cold blooded fish like Bass, that aren’t true Bass, they are in the Sunfish family.

Tom