Fish and Aquatic Conservation

AQUI-S®20E INAD #11-741

photo of a Largemouth bass
Largemouth bass in coontail.
Credit: Ryan Hagerty, /USFWS


Aqui-S®20E is a liquid containing 10% eugenol that is applied as an immersion bath treatment. Aqui-S®20E is only available for purchase through AquaTactics Fish Health. The primary goal of field studies conducted under INAD #11-741 is to evaluate the efficacy of Aqui-S®20E for use as an anesthetic/sedative in all freshwater-reared finfish, freshwater prawn, all saltwater-reared finfish, and sharks. Fish may be treated between 10 – 100 milligram (mg) eugenol per L for up to 15 minutes. Treatment duration will vary dependent upon species, water temperature, and level of sedation desired. AQUI-S®20E should be applied as a single treatment event. For field use, both freshwater and saltwater finfish treated with AQUI-S®20E can be released immediately back into their natural environment; for hatchery use, a 72-hour Investigational withdrawal period is required; and if other INADs that are authorized by the FDA are used with AQUI-S® 20E then the longest withdrawal time needs to be followed. To participate in the INAD Program for AQUI-S®20E visit the data collecting site.

Please read the Study Protocol prior to any treatments. It contains the protocol, SDS, and a copy of the forms to be used as a guide for collecting data that will be entered into the online INAD database. The FDA authorization letters for this INAD are currently only available by emailing Bonnie Johnson .

INAD objective/purpose: Collect scientific data necessary to establish the effectiveness AND safety of AQUI-S®20E as an anesthetic/sedative in a variety of fish species under a variety of environmental conditions.

Drug Name

Drug Source
AquaTactics Fish Health
12015 115th Avenue NE, Suite 120
Kirkland, WA 98034

Tom Goodrich
Phone: 425-922-4208
Fax: 425-629-8095: email:

Sedation levels:

  • Handleable level of sedation is the most commonly used sedation type. This is a lighter level of sedation that has a shorter treatment duration (i.e., fin-clipping, PIT tags, or weights and measurements).
  • Anesthesia to surgery levels of sedation will only be used when fish require a deeper level of sedation and has a longer treatment duration (i.e. surgical implantation of a radio tag).

Method of administration: Immersion; standing bath treatment only

Treatment dosage:

  • 10 to 100 mg eugenol/L (note: AQUI-S®20E is 10% eugenol – active ingredient). Treatment dose will vary dependent upon species, water temperature, and level of sedation desired.
  • The following options are the doses and duration recommendation for fish sedated to the handleable level:
    • Option A: Handleable sedation for salmonids is between 25 – 40 mg/L; sedation time no longer than 5 minutes; and recovery time less than 20 minutes.
    • Option B: Handleable sedation for non-salmonids is between 40 – 100 mg/L; sedation time no longer than 5 minutes; and recovery time less than 20 minutes.

Treatment regimen:

  • Treatment duration is up to 15 minutes. Treatment duration will vary dependent upon species, water temperature, and level of sedation desired.
  • AQUI-S® 20E should be applied as a single treatment event.

Investigational Withdrawal period:

  • 72 hours for hatchery use
  • Freshwater and marine finfish that are sedated by resource managers as part of field-based fishery management activities can be released immediately after treatment. The immediate release provision is for field use only.
  • No Investigational withdrawal period is required for fish that are not susceptible to legal harvest for a period of 72 hours post-treatment.
  • Euthanized fish must not be sent to slaughter or be otherwise available for food.
  • If another INAD is used along with AQUI-S®20E treatments then the longest withdrawal time must be followed.

Concomitant treatments:

  • Only INADs that are authorized by the FDA can be used during the AQUI-S®20E treatments. No other chemicals are allowed to be administered for 2 weeks prior; during; or 2 weeks after the AQUI-S®20E treatment. Contact AADAP for additional information regarding concomitant treatments.

Required test parameters:

  • Investigator must collect data documenting: 1) time to sedation; and 2) time to recovery from sedation. Investigator must also report general fish behavior and any adverse effects relating to treatment.
  • If the recommended handleable levels of sedation are not used then a deviation statement is needed in the Results Report form explaining why a lower/higher dose was used. Treatment doses cannot exceed 100 mg/L.
  • If fish used in a hatchery study are released prior to 72 hrs post-treatment, then a reason for this early release is needed to show how they are not catchable in the Results Report form.

Limitations or restrictions on use of drug:
  • Investigator must follow all instructions in the Study Protocol for INAD 11-741 regarding drug acquisition and handling, fish treatment and disposition, and data reporting requirements.
  • Drug discharge must be in compliance with local NPDES permitting requirements.

Required INAD fee: $700/facility/year

AADAP Contact Information:
Ms. Bonnie Johnson, FWS-AADAP
Phone: 406-994-9905
Fax: 406-582-0242