Truth be known, fish physiology probably changes by some degree from when a fish is a youngster, a teenager, middle age and old age,
To be sure, Bill, my metabolism ain't what it used to be!
More in-depth studies need to be conducted using big old fish
I agree with this so very much!
A good place to start is testing large fish for weight decline for periods of starvation at differing temps. The decline in weight is a function of metabolism and if large fish lose weight at slower rates than smaller fish do at the same temp ... then their metabolism is running slower. That's a very good initial test that at least tells us whether large fish have similar metabolic demand. This same test could detect stress by determining the temperature where metabolism falls off significantly. This would be evidenced by slower weight decline than lower temperatures. A particular interest for me would be understanding if there exist critical DO concentration that varies over a range of temperatures associated with a lower metabolism. If found, then it could serve as a scientific definition of thermo-hypoxic stress.
Additional tests with forage can be conducted to determine consumption at various temps. If the maintenance ration is consistent with the maintenance ration of small adult fish then this would demonstrate that the science I have relied on also applies to large fish. FWIW, the maintenance ration for a 7" LMB is estimated to be around 5.59 lbs BG/annum per pound of body weight for a Tulsa location. A 7" fish is still growing geometrically and so this may be too high for maintenance of adult LMB. LMB seem to merge with a linear path of annual growth once they reach 9 to 10" length. After reaching this milestone LMB tend gain annually at the same increment (eg 1 lb or more a year depending on climate and its internal clock for growth) if they are consuming to satiation. So, in particular, I would be interested in understanding whether there are differences of maintenance ration for 1 lb LMB and larger sizes (as large as could be tested).
I am more interested in characteristic growth, maintenance, and conversion up to no more than 6 years of life. I am totally uninterested in the comings and goings of geriatric LMB. So perhaps I will be able to contribute to our understanding of young to middle aged adults in the future.
