Evaluation of marking and tagging methods for genetic studies in carp

A variety of marking and tagging methods were tested on common carp (Cyprin us carpio L.) with the aim of identifying suitable methods for genetic stud ies in this and other species of carp. Elastomer and Alcian blue dye markin g; Cold and Silver nitrate branding; Floy; Fingerling, Carlin disc and visi ble implant tags; and fin clipping were all tested on a range of sizes of c ommon carp (from mean weights of 10-25 g up to 600-800 g). The branding and tagging methods tested did not give satisfactory retention rates. A combin ation of elastomer marking and fin clipping was then tested as a method for strain identification in a growth comparison trial on catla (Catla catla H amilton) and found to be satisfactory for this purpose. Passive integrated transponders (PIT) tags were used to individually identify catla of wild or hatchery origin being grown for use as broodstock. These had almost 100% ( 98.8%) retention rates, but are expensive compared to most other tagging me thods.