Pond Boss
Posted By: Instar Fulton's factor and Carp - 02/19/13 04:10 PM
I am looking for a source for the accepted Fulton's factor values for common carp (Cyrinus carpio).
Posted By: esshup Re: Fulton's factor and Carp - 02/19/13 04:31 PM
Is Fulton's factor values the same as relative weight?
Posted By: Dave Willis Re: Fulton's factor and Carp - 02/19/13 05:51 PM
Instar, this is probably more information than you want, but maybe not?? smile Regardless, here goes. It's really hard to find accepted values for Fulton's condition index because the values get larger as fish get bigger. So, as an example, the accepted values for 10-15 inch carp would be a lot lower than for 25-30 inch carp. I hope that makes sense. If you are familiar with Fulton's condition factor, you might be familiar with Carlander's Handbook of Freshwater Fishery Biology, Volume 1? It would at least have some comparison information on Fulton's K from other fish populations across North America. I might be able to photocopy those pages and mail them to you??

Instar, if you meant the standard weight equation for common carp (so you can calculate relative weight, as Scott asked in response to you), I have that in either metric (mm-g) or English (inches-pounds) units. I could give you the equation right away here on the Forum, or if you gave me a day or so, I could get an extended standard weight table for common carp. I'd need to know if you wanted inches-pounds, or mm-g.

Scott, no, Fulton's condition factor is not the same as relative weight. It was a pre-cursor and is more difficult to use. Again, this is probably overkill but Fulton's condition factor using fish total length and metric units (mm-g) is 100,000 times the weight, then divided by the length cubed. smile Sorry....
Posted By: ewest Re: Fulton's factor and Carp - 02/19/13 07:30 PM
Here is the history - btw Fulton did not devise the idea or formula nor is it particularly accurate even though used for a long time.

http://folk.uib.no/nfiag/nfiag/reprints/NashETAL2006Fisheries.pdf
Posted By: Dave Davidson1 Re: Fulton's factor and Carp - 02/19/13 09:46 PM
Hey Dave, now I see why RW got popular.
Posted By: Dave Willis Re: Fulton's factor and Carp - 02/19/13 10:28 PM
Yes, Dave, you always quickly cut to the heart of the matter. smile
Posted By: esshup Re: Fulton's factor and Carp - 02/19/13 11:23 PM
Dr. Dave (to differentiate from the Guv):

I thought I read something a while back and then it bounced to RW (WR), with a formula, so that's why I was asking.

Now, the big question is:

For our purposes, are the RW charts "good enough" for wild caught and raised fish? Or is Fultons Factor more accurate?
Posted By: ewest Re: Fulton's factor and Carp - 02/20/13 01:48 AM
There are other condition indices. Fulton is not particularly accurate. Sex , time of year , spawning condition , location , species and size class among others.

RW and the eyeball test are enough IMO.

Just went back over Wr (relative weight), Kn (relative condition factor) and Fulton in Fisheries Tech 2nd and am even more uncertain. Looks like they all have limitations but do provide useful info.
Posted By: Dave Willis Re: Fulton's factor and Carp - 02/20/13 02:51 PM
Scott, both Wr and Fulton's condition factor (usually K or C) use the same information, so honestly would have the same accuracy. Did the pondowner or biologist use a good scale or cheap scale, did they measure to the millimeter or just to one inch, or even are they using mm-grams vs inches-pounds? I will spare you the discussion of accuracy vs precision. smile

"Good" or "high" Fulton's (or similar) condition factors will vary by fish species and by fish size, so it is hard to interpret without comparison data. I think that is what Instar was originally requesting. The advantage of Wr is that a value of 100 means the same thing for all fish species, and all lengths of fish within a species. Thus, much easier to use. However, you have to have that reliable standard weight equation of expected weights by length for each fish species. Do you trust the darn scoundrels (darn biologists) who created each equation? smile

Now for an advertisement! Just by chance, Sir Lusk and I are just starting a series of articles on Wr in Pond Boss magazine. In the upcoming issue, we talk about how to calculate Wr, warn a little bit about how the Wr values will change seasonally, and then provide the standard weight tables for largemouth bass and bluegill. For the next year or so, we'll work through a lot of the common fish species. Right now, I'm working on the article for the May/June issue in which we are doing walleye and yellow perch ("coolwater" fishes). So, everyone stay tuned for that. Advertisement closed. smile
Posted By: Instar Re: Fulton's factor and Carp - 02/20/13 04:07 PM
Thanks gentlemen.

For some reason, PondBoss did not notify me of comments to my original post.
I have found the Fulton's factor condition values for most other freshwater game fish, but not common carp.
Posted By: esshup Re: Fulton's factor and Carp - 02/20/13 05:21 PM
Dave:

Those articles will be a good library reference! Thanks for the answers.

A for do I trust them, it depends who they are. wink
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