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Frequently Asked Questions

Find answers to our most frequently asked questions. Please contact us if you have any further questions or would like more information about AQUI-S® or Fish Welfare – our team is always happy to help.

1. Why would you want to anaesthetise fish?

AQUI-S® is most commonly used to manage stress and animal welfare in aquaculture operations and during scientific research.  Like any other animal, fish are highly sensitive to stressful situations – which can result in high mortalities, fish that are more susceptible to disease and fish that have reduced growth potential. When stressed during the terminal harvest, fish can be damaged and have compromised muscle quality which leads to reduced market value. Find out more about fish welfare HERE.

2. Who can buy AQUI-S®?

In all territories where AQUI-S® is registered, it is done so as a veterinary medicine. This does not necessarily mean, however, that you require a veterinary script to order the product. Please use the CONTACT US section to enquire with your local distributors about the order process.   

3. Who is using AQUI-S®?

AQUI-S® is used in the aquaculture and fishing industries, by universities and research organisations, private and public aquaria, fish breeders, local councils and by hobbyists. Our biggest customers are Salmon farmers in Europe and around the world, where AQUI-S® is routinely used to improve welfare during disease treatments and to increase the value of the final product. AQUI-S® is also used extensively for live lobster transport to international markets.

4. What are the applications?

The applications for AQUI-S® are endless. AQUI-S® reduces stress and improves animal welfare during general handling, health checks, vaccination, disease treatment, live transport, slaughter, euthanasia, general research, aquarium maintenance and animal surgery.  It can be used for light sedation during long transfers, right up to deep anaesthesia such as that required for surgery. Check out an overview of the products applications HERE.

5. Can fish feel pain?

There is sufficient evidence to suggest that fish and crustaceans can experience both pain and fear.  Learn about FISH PAIN and CRUSTACEAN PAIN & WELFARE in these sections of the website.

6. What animals can I use AQUI-S® on?

AQUI-S® is effective on all aquatic animals with developed gill structures – finfish, crustaceans, molluscs and elasmobranchs (sharks & rays). Here at AQUI-S New Zealand Ltd, we always recommend new customers using AQUI-S® conduct a simple bench trial to determine the best dose for their application, species and operation. Feel free to CONTACT US directly to discuss setting up one of these bench trials.

7. How does AQUI-S® work?

AQUI-S® is a liquid formulation which is dispersed in the treatment water, where the active ingredient is absorbed across the gills of the fish. It then acts on the central nervous system to induce anaesthesia and analgesia (pain relief). The same dose can be used to treat a population of different sized individuals, as they effectively self-dose as they ventilate.

8. What are the active ingredients?

The active ingredient of AQUI-S® is isoeugenol – a natural compound derived from the essential oil of the clove plant, Syzygium aromaticum. Our AQUI-S® 20E product contains eugenol, also derived from the clove plant.

9. Is it safe?

The active ingredients are GRAS (generally recognised as safe). As a fragrance with a spicy, carnation-like odour, isoeugenol is incorporated into numerous household and personal hygiene products, including perfumes (0.4%-0.8%), cream lotions (0.015%-0.1%), soaps (0.03%-0.3%) and detergents (0.003%-0.3%). As a flavouring agent, isoeugenol is added to alcoholic and non-alcoholic drinks, meat, baked foods and chewing gums. Isoeugenol is also a by-product of the smoking process in fish and meats.

10. Does it work on people?

AQUI-S® is extremely effective when used on aquatic animals. The active in AQUI-S® is readily absorbed into the bloodstream of aquatic animals via the gills. A similar systemic action is not possible in mammals for obvious reasons.  Therefore, AQUI-S® will not induce the feeling of sedation or anaesthesia in someone who is inadvertently exposed to the active.  We would still prefer to be proactive in this space by recommending all operators wear personal protective equipment (PPE) as per the label directions.

Similar actives are, however, known to have local analgesic properties when used in dentistry. 

11. Can I use AQUI-S® for my pet fish?

Yes! AQUI-S® can be used whenever your fish might get stressed – from transporting it home from the pet shop to introducing it to a new tank, doing water changes and tank cleaning, or treating for diseases.

12. What happens to AQUI-S® in the environment?

The active in AQUI-S® will biodegrade in water and will not bioconcentrate or persist in the environment. Environmental effects data indicate that when AQUI-S® is used at normal treatment concentrations ranging from 20 mg/L to 40 mg/L, the active in AQUI-S® is safe for acute exposure and, after release to open water, will be rapidly diluted to levels considered safe for chronic exposure to aquatic organisms.

13. Are fish that have been sedated with AQUI-S® safe to eat?

Yes! In territories where AQUI-S® is registered with a zero withholding period, the authorities have determined that a fish harvested in combination with AQUI-S® are safe to eat.  Regardless, isoeugenol is likely consumed as part of your daily diet even if you don’t know it.  As a flavouring agent, isoeugenol is added to alcoholic and non-alcoholic drinks, meat, baked foods and chewing gums.

14. Does using AQUI-S® during harvest make the fish taste different?

Residual AQUI-S® in the tissue is not enough to affect the flavour or smell of a harvested fish. The energy being conserved during a rested harvest will, however, result in a fish with a favourably higher pH and a fillet that is often perceived to be sweeter than a stressed fish at harvest. This difference can sometimes be mistaken for the taste of clove. Read more about quality improvements HERE.

15. Where can I buy AQUI-S®?

We have distributors who sell our products around the world. Find a distributor near you in the CONTACT US section of the website.

16. How do I know how much AQUI-S® to add?

AQUI-S® is highly concentrated so you will need to ensure the correct dose is used for your specific application. Dose rates can be found in the various application pages on this website. In order to determine how much AQUI-S® you need for your tank, we urge you to use our online calculator HERE.  If you have any doubt or questions then please don’t hesitate to reach out to our technical team.

17. What support do you offer your customers?

At AQUI-S New Zealand Ltd, we want to share our vast knowledge with you. Our staff regularly conduct trials with new and existing customers to ensure AQUI-S® is used in a way that produces the best result for the customer and the biggest welfare gain for the fish. Feel free to CONTACT US directly with questions or requests for further information.