Research to Business
Offer: 630

An ID card for fish

A barcode for fish enables individual animals to be identified and tracked, especially in research and fish breeding.

A detailed view of the plastic thread with an all-round well visible barcode structure made of gold.

Not only can fish be admired in zoological aquariums and in ponds, rivers and the sea, they also play an important role in genetic research. For this purpose, it is important to be able to identify individual animals, both for medical examinations and for series of experiments with schools of fish in which the animals have to be observed.

State of the art

So-called RFID chips are used for non-contact identification with electromagnetic waves. Here, a reading device reads a transponder in or on the organism. Underwater, however, this method fails because the radio frequency’s signal strength is too low. On the other hand, colour markings and injections are not traceable and have to be renewed regularly. What both marking methods have in common is that the foreign bodies and colours disturb the natural behaviour of the fish and fellow members of the species. Thus these behavioural studies are not representative.


Scientists at the KIT Institute of Microstructure Technology (IMT) are solving this problem with tiny barcodes and infrared camera technology. With the aid of lithography, the standardised barcode, made of gold, is attached to a thin biocompatible plastic thread. This flexible thread is injected into the fish underneath the dorsal fin, so that it can hardly be felt under the skin and is invisible. Only with the aid of infrared irradiation, in which the bodies of the animals appear to be almost transparent, is the barcode visible for the infrared camera. Special image recognition software helps in evaluating the barcode. The unambiguous barcodes ensure that the animals can be distinguished from one another. In addition, when several cameras are used, movements in the aquarium can be tracked.


In the initial step, the technology has been developed for research, although it is also suitable for very different areas, for example for identifying high-value fish that are being bred, for large-scale aquariums or for fish breeding. In the food sector, the barcode could be used to maintain the traceability of the delivery chain.

Options for companies

KIT is looking for institutions and enterprises that are interested in applying the technology and seeks to discuss further fields of application for this marking method.

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Your contact person for this offer

Dr. Aude Pélisson-Schecker
Innovation Manager Energy
Karlsruhe Institute of Technology (KIT)
Innovation and Relations Management (IRM)
Phone: +49 721 608-25335
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