Introducing Digifish™ – RFID Fish Tagging  

Fish research can often be challenging. Distinguishing between different fish within a group can be particularly difficult, especially when researchers are looking for a specific, unidentifiable fish in an environmental study. 

To tackle the issues associated with studying fish, such as their size and delicacy of fish groups in preclinical and environmental research, Somark developed Digifish as an extension of our existing technology, Digitail. Digitail boasts as the world’s smallest RFID tagging system and provides one of the simplest and most accurate means to study rodent populations. This is particularly beneficial when researching larger groups, as traditional methods like ear tagging can be quite cumbersome for lab technicians.  

Digifish incorporates many features of Digitail, adapting the world’s smallest RFID tag designed for rodents to be suitable for fish populations. 

This blog aims to highlight the benefits of using Digifish for researching fish cohorts, our partnership with experts at Hinchinbrook FRyID, and the reasons why researchers should consider adopting Digifish in their methodologies to enhance data collection efficiency, accuracy, and convenience. 

From Digitail to Digifish™: Evolving RFID Tracking Technology

Digitail was developed after the introduction of glass transponders, which were initially used in pets and later adapted for lab animals. Glass transponders required researchers to use 12-15-gauge needles, necessitating skilled technicians to accurately surgically implant the transponders into rodents. Recognising these challenges, Somark created Digitail, which replaced the large gauge needle with a more user-friendly and enhanced welfare 21-gauge needle, allowing even novice technicians to perform the injections with ease. 

Customers around the world recommended Digitail for various rat and mouse studies, praising it for its ease of implantation, readability, and reliability. The primary goal of Digitail was to enhance the welfare of research animals. It received accolades for improving animal welfare, achieving 100% accuracy, and enabling immediate data capture of animal IDs into research systems. 

The flexible and flat form factor of DigiFish™, measuring just 6mm long, 0.5mm wide, and 0.25mm high, makes it suitable for subcutaneous or intraperitoneal placements in much smaller and more delicate fry and common laboratory fish species, such as zebrafish and guppies. The new tag is quick and easy to apply using Somark’s automatic preloaded sterile applicator system, features a permanent 24-character ID, and is easily read out of water by a high-powered UHF reader.

Core Benefits of Fish Tagging for Fish Cohorts and Research Programs 

Why Traditional Fish Tagging Methods Fall Short 

Traditional methods of fish tagging and identification, while still in use, do not provide the reliability and accuracy offered by Digifish. 

One such method, Batching, involves grouping fish into separate tanks for study (control and variable or genotype). This approach lets researchers distinguish between groups. It does not track the behaviours or outcomes of individual fish, and data can become easily confounded or biased by variation between individual tank conditions or social structures.

Another outdated technique is visible implant dye marking, which involves applying small dots of colored dyes to each fish, either underneath the skin or on the fin. These dyes may be visible or fluoresce under specific UV lights. This method has its drawbacks: it is extremely tedious to apply, the dyes can fade and migrate, there are a limited number of colour variations, and it relies on manual visual checks, which may be subjective depending on the researcher. It is generally considered to be a Batch Marking technique except in very small groups of fish.

Fin clipping is another Batch Marking method, and it is arguably the most destructive way of tagging fish. This technique involves intentionally clipping parts of a fish fin to create a mark. Not only does this cause harm to the fish, but it also requires manual visual recording and can skew research results. As a result, the fish may experience significant stress and trauma, and research objectives may be biased by increased risk of infections.

While traditional fish identification methods have served laboratories well for years, they are beginning to show their limitations in today’s fast-paced, high-precision research environment. In summary, traditional methods simply cannot meet the demands of modern preclinical research. 

How Digifish™ Revolutionises RFID Tracking for Fish Cohorts 

Digifish was developed to address the challenges in fish research and enhance the process, making it smarter, faster, and more reliable. Here are its key features: 

• Unique IDs for Every Fish: Each fish receives a permanent 24-character ID that can be read using UHF technology, eliminating the need for stressful physical tagging. 

• True Individual Tracking in Groups: Even within large groups, every fish can be monitored individually, allowing for precise tracking of individual metrics such as growth rates and response to test variables, while controlling for external variables such as water quality and feed rates equally amongst the group.

• All-in-One Digital Integration: Each ID is automatically linked to an individual fish, providing a comprehensive view of each specimen. 

• Stress-Free Monitoring: The system uses automated tracking methods that minimise handling, helping to improve fish welfare and provide cleaner, more reliable data. While tags still need to be removed for manual scanning, the overall process reduces stress compared with traditional methods

• Scalable and High-Throughput: Whether conducting a small experiment or a large-scale study, Digifish ensures that your data remains accurate, consistent, and easy to manage.

With Digifish, researchers finally have a system that meets the demands of modern preclinical research while prioritizing the welfare of fish. 

Partnering with Hinchinbrook FRyID to Advance Fish Research 

Somark has partnered with Hinchinbrook, a world leader in fish marking and tagging technology focused on fish research, to create FRyID. This innovative equipment is perfect for non-laboratory research, including environmental toxicity studies, restoration effectiveness research, population monitoring, and more.  

By combining Hinchinbrook’s expertise with Somark’s advanced technology, we have revolutionized the accuracy and quality of data in fishery research. Hinchinbrook has been a distributor of FRyID since 2019, and it is available for purchase on their website. 

Thanks to our collaboration with Hinchinbrook, we have successfully tested FRyID on a variety of species, beyond just Zebrafish. FRyID has been implanted in Chinook and coho salmon, steelhead trout, shiners, smelt, goldfish, and zebrafish, with sizes ranging from 27 to 80 mm in fork length. As with all fish tagging systems, performance may vary based on species, size, implantation site, environmental conditions, and the tagger experience. 

 

Best Practices for RFID Fish Tagging and Cohort Tracking – Digifish™ 

Digifish and FRyID systems are revolutionizing the way researchers track individual fish, especially in situations where precision and welfare are crucial. These systems are particularly suited for zebrafish disease modelling, as monitoring the progression of illness or treatment of responses in individual fish is vital. Additionally, they excel in environmental and ecological monitoring of small fish species, enabling scientists to study movement, behavior, and survival over time without excessive handling. Longitudinal studies and early-life behavioral research also benefit, as each fish is equipped with a permanent, unique ID from juvenile stages onward, ensuring continuity throughout long-term research. 

Key Considerations for Successful RFID Fish Tagging

To ensure accurate and welfare-friendly tracking, there are several important considerations:

• Tag size: Must be suitable for the fish’s mass and species to avoid stress or injury.
• Rapid and accurate injection technique: Proper administration ensures the tag remains secure, and the fish stays healthy. 
• Tag reading: UHF tags cannot be read underwater, so tags must be removed from the water for scanning. Using our recommended readers ensures the most accurate and consistent reading of tag numbers.
• Anesthesia: To reduce risk of injury to fish, it is generally recommended to anesthetize for tagging and collection of measurements. Anesthesia is not required for subsequent scanning of tags, which can be done quickly and effectively with the fish contained in an aquarium net.

Consult Experts for Your Fish Cohort Tracking Needs!

Choose Digifish™ for Smarter, Welfare-Focused RFID Tracking 

In conclusion, Digifish and FRyID represent significant advancements in fishery research. Their ability to maximize data readability and collation has revolutionized the field. These methods make traditional approaches, such as batch marking, seem outdated, and prioritize the well-being of research subjects. Digifish employs minimally invasive techniques that are straightforward to use, even for novice technicians. 

We strongly encourage you to book a virtual demo to see how Somark can transform your research. 

If you’re interested, please reach out to us or explore some of our other innovations, such as Labstamp and Digitail. 

Contact us today.