What food carries the most protein??? a 5" shad, a 5" bluegill or a 4" crawdad??? Anyone know...........

5" BG full grown with and having a belly full of optimal or aquamax or similar feed. lol

Thats a good question but I would be you would get the most bang for your buck with the BG.

I would say the BG as well at those sizes. Your looking at maybe 14 grams of protein for the shad and crawdad. I bet 18 to 21 grams for the BG I bet. Just a guess tho.

RC

I would agree with the BG as well. Purely based on...at the lengths given, the BG would weigh the most being a taller fish than the shad and a 4" crawdad doesn't really have much to it. Gram for gram though could be a different story. Then I might bet on the crawdad as most of it's body mass is meat and gut.

Good question. I have some info - will find. Hint its not what you think. My guess for nutrients craw 1st , shad 2nd and BG 3rd. Based on the quality of the item not size.

Eric, that brings up a question: Does it matter what kind of feed the BG eat that are subsequently eaten by the LMB?

If one kind of feed contains superior nutrients, of course it should grow bigger BG. But my question is will that BG, ounce for ounce, be more nutritious for LMB than others?

You know what they say... You are what you eat.. lol

I don't know but I would think a well fed BG would be much better then one fending for itself in the wild, but yes good question hopefully Eric and get some answers for us. Thanks Eric!!

RC

An excellent question ! I would guess that a well conditioned fish is a better food source than one the same size but underfed. Because all food is broken down into its basic components and then used by the fish, most well conditioned fish are equal in quality. Probably some minor differences but I have not seen any info on that.

That of course assumes "well conditioned". If all the forage fish in the pond are obese (containing to much fat) then that could pose other problems.

I think you will find that the nutrition value of high to low goes from shad, sunfishes, then crayfish.

When considering nutrition value, it might help to figure nutrition value per ounce of weight, then figure out how many ounces each of those 3 food items weigh at that length.

i.e., a 5" BG will weigh more than a 5" shad or a 4" crayfish if all in the same "good" body condition.

Is the crayfish measured from tip of claws to end of tail or from tip of carapace to the end of the tail?

I ask this question based on what is happening at La Perla Ranch and the growth of bass from the prawns............wonder if there is anything similar one could stock here in the midwest similar to those Prawns.

Large species of CRAYFISH. Keep in mind that prawns won't spawn in freshwater ponds thus you are buying & stocking prawns each year in the forage pond. Crayfish will readily reproduce and grow in ponds. Don't overlook he is also stocking trout each year as forage.

I think in nutritional studies they measure by body weight.

Many studies are on either wet weight and dry weight and are on equivalent basis (apples to apples)comparison. Bill I think but not sure that ounce for ounce craws are high up the scale due to the meat and fat value.





The clupeids examined during the present study
appear to be intermediate in nutritional value in
comparison with other forage fishes. Mean fat percentage
of Dorosoma spp. (24.2%) exceeded that
ofLepomis spp. (15.2%) and fathead minnows Pimephales
promelas (19.1%), but was less than that
of mosquitofish Gambusia affinis (25.8%) and
golden shinersN otemigonusc rysoleucas(3 4.8%)
(Davis and Boyd 1978). Bluegills Lepomis macrochirus
had lower caloric contents (1.06 kcal-g-•
on a wet-weight basis) than gizzard and threadfin
shad (1.17 kcal-g • on a wet-weight basis) (Minton
and McLean 1982); preliminary data collected
for the present study also showed Lepomis spp. to
he lower in caloric content than the clupeids. The
primary reason for the lower energy content of
Lepomis spp. is probably a higher ash content,
rather than a lower fat content. Mean ash content
of Lepomis spp. was 23.8%; the mean for Dorosoma
spp. was 16.1% (Davis and Boyd 1978).
Scales ofLepomis spp. are larger and thicker than
those of Dorosoma spp., and their skeletal structure
may be more substantial. Scales are about 30-
35% ash on a dry-weight basis (Lagler et al. 1977).
Condition factors are considered to he indicators
of the "degree of well-being, relative robustness,
plumpness or fatness" of fish (Laglet 1956).
Thus, one would expect that fat and caloric contents
would have a strong positive correlation with
condition factor. This was not the case in the
present study; r values were low and variable.
Therefore, condition factors cannot always be
considered to be reliable indicators of the true
"plumpness or fatness" of fish, though seasonal
variation of condition factors do correspond to fat cycles in menhaden Brevoortia spp. (Dahlberg
1969) and in Pacific herring Clupea harengus pallasi
(Hart et al. 1940).

Eric, it'd be interesting to see where trout fit on that comparison.

Yes it would be nice to see a comparison using trout, since I am considering adding some this next winter. Would also be nice to see prawns. I've looked at the feeding of prawns but I think a growout pond is necessary or the cost when buying a grown rawn gets pretty costly

I would not look at this as a strictly protein issue. If protein in excess relative to energy you are gaining nothing. I will be the rainbow trout, if cultured and in good condition, will give a better protein to energy ratio than wild stocks that may seasonally be lower in fat. Crayfish are seasonally very variable in energy that would only partially be offset by cherry picking for peelers / soft-shelled crayfish.

Feed your forage to meet more than just the vitamin and fatty acid issues typically of concern.

I haven't taken the time to read the study, but I wonder if calories expended chasing the food comes into effect? Crayfish aren't fast, and don't take a lot of energy to catch, where I suspect fish are chased and missed more often.

Crayfish easier, usually to capture, although actual intake may be lower per unit of effort because so much of the crayfish is essentially fiber.

Esshup that's a good question!! I bet you got to be right. How many times does that LMB miss that fast 4 inch BG v.s. a crayfish. I bet you a bunch... Or how many times has that bass looked at both and said meh this crayfish is easier to catch it's right here.... lol

RC

I used to play with Spotted Bass individually confined to aquariums where each would eat from my hands. They loved the crayfish offered but in terms of the actual mass of intake, they could consume for fish as they packed tighter in the gut. That was not an issue with soft crayfish whch where also more nutrient dense.

Additionally, the crayfish will retreat to burrows during most of the day when pressured by bass. Crayfish are thus not they easy to consume.

Good points!!

Abstract.—We attempted to control a population of papershell crayfish (Orconectes immunis) in an 11-hectare fish-rearing impoundment in Jackson County, Wisconsin, by using traps and by stocking largemouth bass (Micropterus salmoides). Crayfish were harvested with traps during the summer of 1985, and the pond was stocked with 386 largemouth bass (mean weight, 1.1 kg) in spring 1986. The pond was drained in the fall of 1985 and 1986, and crayfish burrow counts were made to estimate the population. In 1985, we trapped more than 18,000 crayfish, of which 72% were adult males. Trapping had minor effect on the young-of-the-year crayfish. In 1986, the crayfish population was reduced by 98%, predation by largemouth bass being the probable major cause of the reduction.

I would take information available in the paper to calculate mass of crayfish available for consumption during course of study. Then compare that in terms of calories what generally consumed with fish as a prey base. Papershell crayfish are very vulnerable to predation by bass, that is why I seldom see the species in abundance where crayfish eating fish like black basses and members of the goggle-eye clan are abundant.