HomePrevious PageSite Map

Print This Page


Aquaculture of Texas

Craig Upstrom Creates All-Male Freshwater Prawns

from Neo-Females


On December 9, 2011, I interviewed Craig Upstrom, owner of Aquaculture of Texas, the oldest and largest freshwater prawn hatchery (Macrobrachium rosenbergii) in the United States.  Now in his 26th year, Upstrom has shipped more than 80 million animals (mostly postlarvae, but also juveniles) to prawn farmers in the USA, Mexico, the Caribbean, Canada, Hawaii, Europe, Africa and the Philippines.  His customers include small and large farms, universities, high schools, zoos, aquariums, medical labs, environmental testing labs and foreign governments.  In addition, he has set up a system of regional prawn nurseries in the United States, so that farmers can get a jump on the season by stocking juveniles, instead of postlarvae, at the beginning of the growout season.


Upstrom’s most recent achievement is the development of all-male prawns!


Shrimp News: How did you get started in the prawn hatchery business?


Craig Upstrom: A family in Fort Worth, Texas, financed the start of Aquaculture of Texas, and I worked for them doing maintenance and research.  I bought a controlling interest in the hatchery 20 years ago.


Shrimp News: How many prawn farms are there in the United States?


Craig Upstrom: There are about 150 farms.  Some of them are fish farms that are growing prawns on the side, and some of them are less than a quarter of an acre in size.  The biggest farms might be fifteen or sixteen acres.


Shrimp News: Do you recirculate the water in your hatchery?


Craig Upstrom: You bet, I’m at an inland location and don’t have access to saltwater (prawns require a marine environment during their larval stages), and it gets cold here in the winter, so I have to heat my water.  I really don’t have any choice in the matter; I have to retain the salt and the heat in the water.


Shrimp News: How has the concept of regional nurseries worked out?


Craig Upstrom: The regional nurseries use technology that I developed over the past twenty-five years, and they have really worked out well.  Currently, I work with nine regional nurseries in the United Sates.  It’s really the only way to get juveniles prawns to the farms at the beginning of the growout season, which means we must have nurseries that are heated during late winter so that farmers can stock in the early spring.  This concept is unique to the United States.  It’s not done this way in the rest of the world because in the rest of the world prawns are grown in much warmer climates.  I give all my technology away to the regional nurseries; however, with the new all-male prawns, I might move to a formal contract or a franchising arrangement.


Shrimp News: So you basically make your money by selling postlarvae to the nine regional nurseries?


Craig Upstrom: That’s right, we sell then postlarvae in late winter, and they sell 30, 45 and 60-day-old juveniles to the farmers in the spring.  Currently, for normal postlarvae, I’m charging $30 a thousand.  From hatching, it takes a prawn 30 to 33 days to reach the postlarval size, about twice as long as it takes for Penaeus vannamei.  Juveniles are generally sold from the regional nurseries at 8 to 12 cents each, which works out to between $80 and $120 per thousand.


Shrimp News: Do you also sell juveniles?


Craig Upstrom: Yes, I sell them for about $80 a thousand, less for small ones and more for big ones.  The size of the order also affects the price.


Shrimp News: Do you produce any market-size animals?


Craig Upstrom: Some.  I do a lot of research on growout systems, intensification, equipment, tanks and that sort of thing, so I always have some mature animals around that I can sell.  I used to rent some ponds for growout, but I’m not stocking any ponds now.


Shrimp News: How do you ship your postlarvae to the prawn nurseries?


Craig Upstrom: We put them in plastic bags and Styrofoam boxes and send them airport-to-airport, or via Federal Express and UPS.  If it’s more cost effective to deliver them ourselves, however, we truck them to the farm.  Also, some people come to the hatchery and pick them up.  I also export prawns to farms and research facilities around the world.  Exports are really nice because the orders don’t all come in at the same time the way they do during the spring stocking season in the United States.  Exports allow me to spread the costs of running the hatchery over a longer time frame.




Double ZZ All-Male Prawns





Shrimp News: Why grow all-male prawns?


Craig Upstrom:


• Males grow much faster than females, and reach a larger size.

• The market likes large prawns and pays more for them.

• All-male prawns have the potential to double pond production in the USA.

• All-male ponds eliminate skewered size distributions in ponds.

• The process requires no chemicals, hormones or genetic manipulations.


Shrimp News: How do you create all-male prawns?


Craig Upstrom: It’s basically done through the removal of the androgenic gland in the males, which turns them into neo-females.  We then mate those neo-females with normal males to get all-male offspring.


Shrimp News: How did you learn how to do that?


Craig Upstrom: A fair amount of research has been done on creating all-male prawns, but the only concept that made sense to me was the work being done on the removal of the androgenic gland, so I started by reading all the research I could find on the androgenic gland in crustaceans.  Unfortunately, most of it was theoretical.  It took me more than four years to perfect procedures that worked.  It was all trial and error experimentation.


Shrimp News: I like the name—“Double ZZs”—that you’re using for the new, all-male prawns.  How did you come up with that name?


Craig Upstrom: In crustaceans, the sex chromosomes are ZZ for males and ZW for females (unlike mammals that are XY and XX), so ZZ means they have two male chromosomes.


Shrimp News: Will you have all-male animals ready for sale by the spring of 2012?


Craig Upstrom:  I should!  Last year, I produced 100,000 in one batch.  I hope to have millions of animals ready for the spring of 2012.


Shrimp News: Did you do any growout trials with those 100,000 animals?


Craig Upstrom: Yes, we stocked two of six, 1.5-acre ponds at a customer’s farm in Texas with 20,000 double ZZs per acre.  Due to the extreme drought in Texas last year and chronic low dissolved oxygen levels in his ponds, production was down; however, the largest and highest production of prawns came from the ponds stocked with “Double ZZ’s”.  Not a single female was found in those two ponds.


Shrimp News: How much are you going to charge for the Double ZZs?


Craig Upstrom: I haven’t figured that out yet.  Tentatively, I’m thinking about $60 a thousand.  The nurseries will probably double that figure and sell them for $120 a thousand, which is not a whole lot more than they’re getting for normal juveniles.  I think the production of all-male progeny is going to give the United States prawn farming industry the kick that it needs to move to much higher of production levels.


Information: Upstrom’s website provides lots of information on getting started in prawn farming.

Information: Craig Upstrom, Aquaculture of Texas, Inc., 4141 East IH-20 Service Road North, Weatherford, Texas 76087, USA (phone 1-817-594-4872, email upstrom5@airmail.net, webpage http://www.aquacultureoftexas.com).


Source: Craig Upstrom.  Telephone Interview byBob Rosenberry, Shrimp News International.  December 9, 2011.


Print This Page
HomePrevious PageSite MapTop