NRDPFC









Fish SampleSubmission for Genetic Analysis (fin clip)

Sampling procedures for live release

Collect a fin clip (pectoral, pelvic, adipose or caudal) from each fish being sampled. This method allows us to investigate DNA only, but is the least damaging to fish and works well for releasing fish alive. This is also an easy method to use if members of the public are assisting in the sampling program. Whenever possible, it is preferable to get a large sample size (at least 30 to 50 fish) from each population to ensure a representative sample for that population. Larger sample collections (up to 100 fish per population) are also useful, but not essential.

  • Taking a fin clip for genetic samples using a clean knife, scalpel, or scissors, cleanly remove a whole or partial fin from the fish being sampled. For salmonids, the adipose fin works well as a DNA source and comes off cleanly. For sampling adipose, pectoral or pelvic fins, cutting the entire fin off will heal more quickly and cleanly than removing part of the fin. If a piece of the dorsal or caudal fin is removed, do not take more than one square centimeter of tissue.
  • Dirt and any visible parasites should be removed from tissues as these can affect genetic analyses.
  • Clean the cutting tool(s) and forceps between samples to minimize sample cross-contamination. Rinsing in water and wiping with a clean tissue or cloth is recommended.

Tissue storage

How the finclips are stored and preserved may vary depending on what information is desired from the population and/or individual fish. If field crews are recording data from individual fish (i.e. collecting data for more than generating population means), tissue samples should also be preserved individually.

Individual (scale envelopes):


  1. Label a standard scale envelope (unbleached kraft paper) with all relevant details (date, waterbody, location (latitude and longitude), species, individual fish identification, length, weight, etc.)

  2. Place the finclip in the envelope and loosely close the envelope. Do not seal the envelope, as air and moisture should be allowed to escape to help the fin sample dry out.

  3. If the fin sample will also be used for aging, separate the first three fin rays from the rest of the fin before placing both fin pieces in the envelope.

Individual (ethanol preservation):


  1. Place the fin clip into a small glass or plastic vial containing high strength (80% to 95%) ethanol. The ethanol will preserve the tissue and the DNA at room temperature, so does not need to be refrigerated.
  2. Label each vial with a permanent marker. Ensure each sample can be identified later to collection site, date, fish species, individual number or ID if appropriate, etc.

Population (pooled samples):

If it is not necessary to link genetic data back to morphological data for individual fish (i.e. link genetic profiles of individuals back to their length, weight, age, sex, etc.), finclips from multiple fish within a single population can be pooled for preservation and storage.

  1. Place all fin clips from a single population into a glass or plastic jar containing high strength (80% to 95%) ethanol.
  2. ONLY fish of the same species and from the same location should be placed in the same bottle. Make sure to use one bottle per species if collecting multiple species from the same site.
  3. Label each bottle with a permanent marker. Ensure that each sample set can be identified later to collection site, date, fish species, individual number or ID if appropriate, etc.
  4. Use a pencil to write out the same label information on a piece of paper and place it inside the sample bottle. This will ensure that sample collections can still be correctly identified if the outside label comes off or becomes illegible.
  5. Store the sample bottles at room temperature until ready to be shipped (see below).

If no ethanol is available, fins from individual fish can be dried and stored together, although this can be a bit tricky. Individual finclip samples should be dried before putting them together in an envelope or bottle, to prevent fins from sticking together and causing cross-contamination between samples. Dried fins are also much more fragile, and may break apart during storage or being shipped. For these reasons, it is better to preserve pooled population samples in ethanol rather than drying them.


Label Information

SPECIES:
INDIVIDUAL ID: (if applicable)
LOCATION: waterbody name (sampling location; include latitude and longitude if possible)
DATE: YYYY/MM/DD


 

Natural Resources DNA Profiling and Forensic Centre
DNA Building, Trent University,
2140 East Bank Drive, Peterborough, Ontario, Canada, K9J 7B8
Phone: (705) 748-1011 ext. 7126| Fax (705) 748-1132
Email: info@nrdpfc.ca