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Preserve and Lake Management Articles

Fish that Eat Plants

Grass carp, White amur, Grass minnow (Ctenopharyngodon idella).  What’s in a name?  These fish are in the common carp family and are one of the world’s largest minnows. Perhaps we should call them Grass Minnows. They are originally from the Amur River in Siberia and China.

Size
They grow rapidly, from 10” to 20” in one year and can reach a weight of 20 pounds (24” long) by their third year.

Appetite
They eat only plants; lots of plants. As youngsters, they can eat five times their body weight in plants daily! As adults they still can eat 100% of their body weight each day during the warm weather.

What does triploid mean?
Triploid grass carp (the only ones permitted in Florida) have three sets of chromosomes (instead of the normal two) which render them sterile. Triploids are produced artificially and regulated by the Fish & Wildlife Commission (FWC).

Would grass carp help my lake?
Plants are a natural part of all lakes. Aquatic vegetation provides habitat for feeding, reproduction and shelter for many species of fish, amphibians, reptiles and birds. Fisheries biologists recognize that healthy balanced lakes have about 30% of the lake covered with plants.
Certain plants, usually invasive, exotic species such as Hydrilla have no natural enemies in Florida. These plants can make your lake unusable and easily spread to other lakes. It’s in everyone's interest to eliminate these plants. Grass carp are an excellent solution to some weed problems.

How do I get grass carp?
The FWC requires a simple and free application. A FWC biologist will evaluate your application and if the permit is approved, recommend the number of triploid grass carp to deal with your problem.  If your site has escape routes, you are required to install a fish barrier before your permit is issued. Consent of all waterfront property owners is also required prior to permitting.

Fussy eaters
Grass carp eat a lot, but they have very distinct tastes. They have to be on the verge of starvation before they will eat plants they don’t like.  Their feeding preferences change as they mature. Visit http://aquat1.ifas.ufl.edu/photocom.html to see images of the plants.

Please call if you want more information about grass carp or plant control. (941) 284-0440

Crass Carp Favorite Food
Frequently eaten

Brazilian elodea
Duckweed
Elodea
Hydrilla
Musk-Grass, Chara
Pondweed
Slender Spikerush
Southern Naiad
Widgeon-grass

Sometimes eaten
Filamentous Algae
Bladderwort
Coontail
Eelgrass
Fanwort
Maidencane
Naiad, Marine
Nitella
Salvinia
Soft rush
Spikerush
Torpedo grass
Water-meal

Rarely eaten

Alligator-Weed
American Lotus
Azolla
Baby-tears
Bacopa
Bog-Moss
Bulrush
Burhead Sedge
Cattail
Common Arrowhead
Duck-Potato
Frog's-bit
Hygrophila
Knotgrass
Limnophila
Para grass
Parrot's-feather
Pennywort
Pickerelweed
Red Ludwigia
Rush Fuirena
Sawgrass
Sedges
Smartweed
Spatterdock
Water-hyacinth
Water-lettuce
Water-lily 
Water-shield

For more information regarding stocking fish and bio-control feel free to call our Beautiful Ponds office (941) 488-1942.

Animals