A note by Dr. Willis about relative weight:
Folks -- just one caution on interpreting these "standard weights" that we use in the American Fisheries Society reference books.
These "standards" are based on what we call the "75th percentile." That means, for any fish species, for its entire geographic range, for all times of year, 75% of the fish will weight LESS than the standard, and only 25% of the fish will weigh more.
Thus, this value is a little deceiving. We typically calculate relative weight values (actual weight divided by the standard weight for a fish of that length, and then multiplied by 100). Many people think that a Wr of 100 is necessary for fish to be in good condition. In reality, any time you hit about 90 or above, your fish are average or above average. So, don't set an unrealistic goal! 90 is often quite good. However at 90% are those fish achieving the best growth possible? Also note that the RW changes throughout the seasons and year to year due to several reasons.
Hope this helps,
Dave Willis
Relative weight is an index used by fisheries biologists to determine if a fish is in good condition, fat, or thin. It is calculated by dividing the weight of a fish by the expected weight for a fish of the same species at the same length growing rapidly with plenty of food. In the scientific and management literature, this index is usually multiplied by 100 to put it in whole units or percentages. A relative weight below 80 is very thin, around 90 is average, and greater than 100 is considered fat.
Removing Bass Northern Pond
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=20045#Post20045More On Removing LMB
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=21180#Post21180Original Bass at 3 lb & what is needed for getting the best annual growth to get them to trophy size in Indiana,
Included bass growth increment estimates and needed forage per acre,
Plus forage weight needed for adult LMB to maintain annual body weight
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http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=20722#Post20722Bass Heavy vs Stunting
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http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=145580&page=1Questions and Study on angling, catch and recapture
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http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=148095#Post148095What to do with harvested LMB?
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=22401#Post22401Death rate in LMB � mortality
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=22339#Post22339LMB Life Span
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=96912#Post96912http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=22223#Post22223http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=461456&#Post461456Aging Bass
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=130599#Post130599LMB Genetics
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=23352#Post23352Multiple strains - mortality rates - trophies
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=401117#Post401117http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=404369&page=1F1 vs Flordia Strain Northern strain Bass Pros & Cons discussion
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=474327#Post474327North American Journal of Fisheries Management 28:516�522, 2008
American Fisheries Society 2008
Physiological and Ecological differences among FLMB, NLMB, and their hybrids have been documented. For example, they exhibited different critical and chronic thermal maxima (Fields et al. 1987) and different mortality rates when held at low temperatures (Carmichael et al. 1988). In addition, FLMB and NLMB differ in the timing of spawning, growth rate, reproductive success, and survival (Isely et al. 1987; Gilliland and Whitaker 1991; Philipp and Whitt 1991).
Performance differs among endemic units within the historic range of FLMB and NLMB. For example, growth and survival differed between progeny of parents from different drainages in Illinois (Philipp and Claussen 1995). Similarly, swimming performance differed between Illinois and Wisconsin populations of bass (Cooke et al. 2001). Lastly, the survival, growth, and reproductive success of the local stock were higher than those of the nonlocal stock when comparing performance among Wisconsin, Illinois, Texas, and Florida populations at each locale (Philipp et al. 2002).
Growth After stunting
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=23698#Post23698When to stop harvesting LMB
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http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=24218#Post24218Average growth for both sexes of bass in Texas are:
Age I 8 inches, Age II 12 inches, Age III 15 inches, Age IV 17 inches, Age V 18 inches.
From
http://fisheries.tamu.edu/files/201...ment-and-Management-Recommendations-.pdfGood Growth for LMB?
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=125384#Post125384Growth of pellet eating bass Alabama
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=465588#Post465588Growing good sized LMBass in smaller ponds
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=504997#Post504997Forage, optimum stockers/ac, best growth - Florida, Texas
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=461292#Post461292LMB genetics here in Texas are found to be some of the best. Overtons fisheries here comes to mind. I have seen 2.9 lb growth in my pond in 10 months here starting with a 2 or 3" lmb fingerlings. Five lbs in less than 3 years is doable here.
Optimum LMB Growth North - Wisconsin 4" 2 lb/yr at 16"
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=454741#Post454741 More about bass growth questions
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=370091#Post370091Bass relative weight (Wr) weight changes
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=112084#Post112084Wr or Rw Chart
http://lakework.com/wp-content/uploads/2013/01/Largemouth-Bass-Relative-Weight-Index.pdfLMB relative weight Wr and thin bass pics
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=107618#Post107618Food needed for growth
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=130299#Post130299How many fish-bluegill will bass eat per day?
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=429238#Post429238Link from discussion above to the amount of food needed per day by large bass.
http://www.bassresource.com/fish_biology/trophy_bass_prey.htmlThere should be some sort of conversion factor for how many pounds of fish need to be eaten per pound of predator for that predator to grow normally. It would take a better 'bean counter' than me to figure that one out.
I do know that many LMB can grow 1 lb per year (maybe more weight gain in the south with a longer growing season). This equates to about 10 lbs of live meat (bugs, crayfish, fish, amphibians and birds) of some sort per year per fish. If we use a 16" lmb (2.25 lb std wt) as an example this means it could eat around 226 to 453 four inch BG (10-20g ea) to get 10 lbs of BG. More individuals would be consumed if BG were smaller and if the BG were 5" fewer (66). If we had 30 16" lmb in an acre and each was eating 350 BG per year this means they are consuming around 10,000 4" BG per year. If that 10 lbs consumed fish were 2.7" FHM this would for 30 LMB consumers equate to around 44,100 FHM. See now why LMB ponds are often low on forage fish???? Plus as you should be learning by now you do not want your largest or even large bass eating or thriving on FHM or they if they do they will not be gaining weight. Keep reading for more information and answers.
The example above of 30 16" LMB has 67.5 bass pounds per acre - reasonable amount. If each of those bass ate 10 lbs of all fish this is 300 lbs of forage, about all the forage fish weight that would normally live in one acre. Normally I think one would want the predators to eat no more than 60-72% of the existing forage fish stock each year. You need a significant amount of breeder forage fish to carry over to the next spawning year to again create you a forage surplus. In reality there are in natural pond food systems, rarely 30 16"+ bass per acre; too many predators for what that pond can naturally produce. Fish ponds are communities generally comprised of fish of various sizes; many more little ones than big ones. Just a few big predators per acre at the top. I don't think all of those 30 16" bass will eat 10 lbs of forage. Some of the bass may just maintain or slightly increase their weight whereas the most aggressive ones may eat a few more fish than 10 lbs and the majority consume weights somewhere in between 2 to 10 lbs. We should probably cull those slow growing bass. In addition a certain percent of the annual diet will be items other than BG such as other bass, and various vulnerable meat items that live in or around the pond. Diversity of forage items is a key item in well managed ponds.
Feeding Pellets to LMB
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=19991#Post19991Using only female bass to produce primarily all big LMbass
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=387220#Post387220Problems and Optional Ideas for All Female Bass
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=559368#Post559368
