They are sort of underwater lawnmowers. A full grown one is about 6 foot and 100 pounds and eats 200 pounds of aquatic weeds a day. Mine is pretty small, just 27 inches and 8.4 pounds.
http://www.clovegard...jg/grasscarp.html
![]() They are sort of underwater lawnmowers. A full grown one is about 6 foot and 100 pounds and eats 200 pounds of aquatic weeds a day. Mine is pretty small, just 27 inches and 8.4 pounds.
http://www.clovegard...jg/grasscarp.html |
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![]() Check your numbers in your post, please. :-)
Pretty fishie, though. Cheers, Scott. |
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![]() Eh? Looks good to me. 6 foot 100 pounds eats 200 pounds a day, mine 27 inches 8.4 pounds. Yes, a full size grass carp can eat twice its weight in a day.
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![]() Let's see... http://en.wikipedia.org/wiki/Grass_carp
The grass carp grows very rapidly, and young fish stocked in the spring at 20 cm (8 inches) will reach over 45 cm (18 inches) by fall, and adults often attain nearly 1.2 m (4 feet) in length and over 18 kg (70-90 pounds) in weight. They grow 10 pounds a year at least. They eat up to 3 times their own body weight daily. They thrive in small lakes and backwaters that provide an abundant supply of fresh water vegetation. Ok, I can understand when they're young and growing rapidly, they could eat more than their body weight. But when they weigh 100 pounds? http://www.aquanic.o...s/srac/3600fs.pdf (4 page .pdf): Research has shown that juveniles (2.4 to 6 inches, 6 to 15 cm) consume 6 to 10 percent of their body weight in vegetation each day (wet weight basis). As fish grow, the consumption rate increases. Fish weighing 2 to 2.5 pounds (1 to 1.2 kg) can consume more than their body weight each day (in some cases 300 percent). Larger fish can consume up to their body weight per day under ideal conditions. Reportedly, fish larger than 10 pounds eat only 20 to 30 percent of their body weight. Obviously, at these consumption rates grass carp can quickly reduce vegetation if stocked in proper numbers, in good quality water, and at optimum temperature. I guess it depends on the circumstances, but I would still be astounded if there was a 100 pound fish out there that ate 200 pounds of grass a day. AFAIK, the amount of food eaten as a fraction of body mass usually decreases as mass increases (thermodynamics argues that trend - it's an effect of the surface to volume ratio). E.g. Bee Hummingbirds (half their body mass in food, 8x their body mass in water per day - http://www.avianweb....hummingbirds.html ) versus Elephants (which have inefficient digestive systems like the grass carp: up to 600 pounds of food a day for a 12,000 pound elephant - http://en.wikipedia.org/wiki/Elephant ). I remember that some expert on sharks was interviewed when "Jaws" came out. My recollection is that he said that a Great White would live for 6 months or more after eating one person, so terrorizing a town like that wasn't realistic.... (Shocking, I know.) FWIW. :-) Cheers, Scott. |
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![]() . . or not clear enough about size - or yours are over conservative. I'll have to do a little more digging. In any case, they are good eaters.
Now I'll find out if they're good eating. |
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![]() 18 kg (70-90 pounds)is off base as 18 kg is less than 40 lbs. Alex
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![]() ...And citation requested.
The grass carp grows very rapidly, and young fish stocked in the spring at 20 centimetres (7.9 in) will reach over 45 centimetres (18 in) by fall, and adults often attain nearly 1.2 metres (3.9 ft) in length and over 18 kilograms (40 lb) in weight. They grow 10 pounds a year at least. They eat up to 3 times their own body weight daily. They thrive in small lakes and backwaters that provide an abundant supply of fresh water vegetation.[citation needed] -Mike
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin, 1759 Historical Review of Pennsylvania |
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![]() A source with original cites seems to be http://www.dfo-mpo.g...ibrary/286222.pdf (52 page .pdf), but it doesn't give all the numbers in the Wiki entry.
p.10 The colour of adult grass carp is dark gray on the dorsal surface with lighter sides (white to yellow) that have a slightly golden shine. Fins are clear to gray-brown (Page and Burr 1991, Opuszynski and Shireman 1995). p.13 As with most species, growth in grass carp is a function of age, size and abiotic factors such as density, nutrition, temperature and oxygen (Chilton and Muoneke 1992). The most rapid length increases seem to take place in age 0-4 fishes, while weight increases are especially pronounced for age 4-6 fishes (Chilton and Muoneke 1992). Shireman and Smith (1983) presented mean length for each year class for grass carp found in the Amur River basin (Figure 10). (It's a good paper.) HTH. Cheers, Scott. (Who never wanted to know this much about Grass Carp...) |
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![]() This is because they are all triploids (created by damaging the eggs immediately upon fertilization). Triploids only reach about half the weight of diploids and live only half as long, but they eat about 90% as much as diploids eat. They have the advantage that they are sterile, since the California agriculture folks are very sensitive about alien lifeforms reproducing here.
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![]() But, I got Grass Carp all written up (and got nearly half the fish eaten). Then I had to rewrite the Common Carp page (probably more applicable to most people) so it was of the same format and quality as the grass carp page.
And while I was at it I rewrote and revised pretty much the entire carp section of my Fish Varieties page and replaced the mislabeled photograph for Crucian Carp. The old picture was of a carp, I have no idea what kind of carp, but definitely not a crucian. Grass Carp http://www.clovegard...d/sf_carpgrz.html Common Carp http://www.clovegard...d/sf_carpcoz.html Fish Varieties http://www.clovegard...eafishv.html#carp |
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![]() Grass Carp page:
"Personally I don't have a problem with the spines, As with most fish ..." Period before As? Common Carp page: (As above) Varieties of ... page: "It's ability to survive in low oxygen environments made it possible to keep goldfish in fishbowls before the advent of areated acquariums." Its, aquariums. "Actually, Vietnamese catfish is a genus known as "Shark Catfish" from its shape and is different from American Channel Catfish both in flavor and the shape of the fillets which are wider and flatter - bit it's still catfish, not sole." but "This air breathing catfish quickly becomes a pest in subtropical areas. to another." Fragment. "This one can easily be identified by the rows of yellow spots on it's underside and the rounder face" Its, Missing period. "It's habits and characteristics are very similar to the Goliath Grouper of the American coasts." Its. "This fish is endangered by pirate fishing and it's slow rate of maturing." Its. (If you mean the contraction of "it is" or "it has", then use the apostrophe. Otherwise, if you mean possessive, leave it out.) :-) HTH. Cheers, Scott. |
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![]() An "its" check on that file - a lot of that stuff is years old.
As always, thanks for the corrections, they are very helpful. |