Identification of individual prawns with implanted microchip transponders

Implanted microchip transponders, of the type widely used in dogs and cats, can be inserted into the body of a prawn, and read in situ. Specimens of Macrobrachium rosenbergii were selected for preliminary studies. Two large males were implanted with transponders 14×2 mm in size, and 20 smaller individuals with 5×2 mm glass dummies as a test for survival rates. The transponders were inserted into the largest portion of the tail musculature, to minimize nerve cord and aortic compression, or inhibition of movement. Virtually all prawns, large and small, successfully tolerated the procedure. Most went through at least three molt cycles without loss of the implants or significantly increased mortality compared to controls. Implants were not affected by the artificial seawater environment nor the body fluids of the prawns. We suggest that the use of transponder devices, especially if they can be made smaller, is a viable technique in prawn aquaculture to identify `selected sires' and founders of new lines of animals with desirable phenotypes.