My wife and I raise American Bullfrogs (Rana catesbeiana). We began to develop Bullfrogs as an aquaculture species in 1989 after graduating from the Technical Aquaculture Program at the College of Southern Idaho. We provide thirty six customers with live purpose-bred farm-raised Bullfrogs for scientific, medical, and educational purposes.
Our farm is on a 45' by 100' (14 m x 30 m) section of rented ground. We consider our farm to be sustainable. All of our Bullfrogs are produced on site year-round. No herbicides, pesticides, non-organic fertilizer, antibiotics, or electricity are used at our farm. A local mill supplies all of our feed. The collected manure from our animals is composted and the effluent water is used for irrigation. We are in business to make money, we do contribute 10% of gross sales to non-profit organizations, we have no debt, and have never accepted any public funding or government assistance.
You can tell the gender of adult Bullfrogs any time of the year by looking at the tympanic membrane (the circular structure behind the eye). Males have a large tympanic membrane that is about twice the diameter of the eye, a female's tympanic membrane is about the same diameter as the eye. During the breeding season the males will develop yellow coloring on the ventral surface of their head and their thumbs will become enlarged. Females don't develop the yellow coloring and their thumbs remain about the same size as the other three digits. Adult males are the ones that make the characteristic bellowing sound which comes from the tympanic membrane. The tympanic membrane also covers the hearing organs.
In the fall of 1994 the laboratory director at a major medical school saw a small ad that we had placed in the classified section of Reptile and Amphibian Magazine. She called and asked if we could supply her with 20 Bullfrogs to be used for training doctors in microsurgery techniques on blood vessels. We sent them to her; up to that point we had only sold a few pairs to enthusiasts.
A couple weeks later she called us back very excited. Most of the Bullfrogs had survived the surgery and had healed up. Something that had never happened before. She had a colleague who wanted some of our Bullfrogs for heart muscle studies. A light bulb came on in our minds. We had some flyers with some basic info on our farm-raised Bullfrogs printed up they featured a photo of my wife in her lab coat holding large Bullfrogs on her open upturned hands. We mailed them out to some medical schools and got a small response. In the meantime the first two researchers contacted more of their colleagues about our Bullfrogs and we got more orders.
It turned out that laboratory frog suppliers (our competition) were providing wild-caught frogs that were skinny and hyper-active, with worn off snouts, sores, broken bones and digits, and generally stressed out. Our fat, happy, and docile farm-raised Bullfrogs were the exact opposite and they were less expensive. Word spread in the research community, the rest is history.
Our original medical school still orders about 250 live Bullfrogs each year.
Our Bullfrogs average about $61.00/lb., overhead is pretty low now that most of our infrastructure is in place. We have a business License, a Commercial Rearing License, an Invasive Species Possession Permit, and a Live Fish Transport Permit.
Raising American Bullfrogs is actually raising two different animals at once.
Bullfrog larvae/tadpoles are fully aquatic. They are herbivorous/detritivores that will also opportunistically feed on dead animals. Their mouths are designed to scrape off bits and pieces of larger food items, they can also filter feed in "green water". Their diet has to be quite varied in order for them to maintain their health. They are also fairly active in their constant search for food. These factors presented major problems early on in our attempts to turn Bullfrogs into farm animals.
Once the tadpoles have morphed into the adult form, everything changes. They become semi-aquatic, carnivorous, mostly sedentary, ambush feeders. With their oversized mouth they will lunge at and engulf anything that moves. When the "prey" continues to move in their mouth they will use their hands and their eyes in an attempt to stuff it down their gullet and swallow it. If the "prey" doesn't move in their mouth, the Bullfrog will spit it out and wipe it's tongue off with it's hands and refuse to eat that thing again. In addition to engulfing large prey, Bullfrogs also have a long sticky tongue that is attached at the lower front of the mouth. They can flick this tongue out at smaller things that move and whip them back into their mouth. If the small "prey" continues to move, it is swallowed using the eyes to push it down their throat. If there is no movement in the mouth the item is spit out and not eaten again. These behaviors also presented major problems in our attempts to turn Bullfrogs into farm animals.
Along with Bullfrogs being carnivores with very large mouths, they are also cannibalistic. A Bullfrog will attempt to engulf and swallow another Bullfrog that is up to 75% of it's own weight. This can result in the eater being choked to death by the eaten. Very close attention must be paid to keeping the Bullfrogs sorted and segregated by size. "Shooters" can develop overnight. This means that a population of 50 gram average Bullfrogs can have some 70 gram Bullfrogs the next day. Care must be taken to remove them immediately. Tadpoles will also swarm and eat the skin off a morph that is unable to get away from them.
All of our Bullfrogs (larvae and adults) are raised in fiberglass troughs.
The breeding season is fairly short. We morph the larvae into froglets year-round in order to supply our customers year-round with the size, age, and gender that they require.
Larvae and adults are fed pelleted diets that are produced for us by a local feed mill.
We sell nearly every Bullfrog we can produce for laboratory, medical, and teaching purposes. A small fraction (less than 1%) are provided to zoos, museums, nature centers, and enthusiasts. No need to sell them for human consumption for a lower price.
Fascinating! Love the pictures. So do you control light and temperature to morph the frogs? How do you get them to eat pelleted feed? Very interesting to see a different aspect of aquaculture.
Do you make use of the fouled up water?
American Bullfrogs are poikilothermic, nearly every aspect of their life can be controlled with temperature and feed.
It was a five year struggle with dozens of failed attempts/experiments before my wife hit upon a solution to training Bullfrogs to eat pellets, followed by several more years of feed trials to get the pellets right for every life stage.
We strive to remove as much of our animals waste as possible from the natural aquatic environment. Our troughs and pens are all flow through systems with quiescent zones to settle the solids. We use 12 to 20 gallons per minute (gpm) or 45 to 76 liters per minute (lpm) at our farm depending on the time of year.
We collect the tadpoo and froguano from their respective quiescent zones separately. We then layer it into a wooden two bin composting set-up. As bin #1 dries and fills we churn it with a shovel and move it into Bin #2. We have a purpose-built plastic composter that was purchased from the local farm store in which we compost morts larger than tadpoles and morphs. The morts are covered with a layer of compost from bin #2. We don't have morts every day but this gives us a convenient non smelly way to handle them when we do. The finished compost is collected from access doors at the bottom of the plastic bin. The finished compost is unique in that the bones from the composted morts are fairly evident.
Our small farm produces about three cubic meters of finished compost a year. It is given to friends and used on our own garden.
We don't add sawdust. I think the tadpoo coming from herbivores has plenty of carbon in it. The froguano coming from carnivores is the nitrogen source. A couple of winters ago the center of the pile in the plastic composting bin was showing temps of 126 f (52 c).
We dug the compost into the garlic beds before planting our garlic project last fall. The garlic came up right away and grew all winter because the ground stays warm around the Bullfrog pens. The harvest has surpassed our expectations.
This is basically anecdotal evidence.
On May 15th we planted four Ichiban eggplants at the farm from a pony pak purchased at our local hardware store.
Two plants were planted in the light sandy loam with no amendments and two were planted in the same soil but with a couple shovels full of composted froguano dug into the soil first.
These photos taken August 2nd show a striking difference in the size and vigor of the plants. The larger plants have produced three good sized fruits but the smaller plants have yet to yield any fruit.
Both sets of plants have been given about the same amount of water.
Diego Footer on Permaculture Based Homesteads - from the Eat Your Dirt Summit