Shark Tissue Samples Needed to Assist Phylogenetic Research
From the contents of this website, it is obvious I have a long-standing and passionate interest in shark evolution and interrelationships. Working with my colleague, Mahmood Shivji of Nova Southeastern University, I am presently undertaking an ambitious multidisciplinary project toward resolving some ambiguities in shark phylogeny. Essentially, we are combining evidence from molecular genetics and morphology to provide new insights into how living sharks are related to one another. To do that, we need tissue samples from as many shark species and from as many geographic regions as possible. Volunteers willing to collect shark tissue samples on our behalf are invaluable to this on-going research. At present, we are particularly interested in receiving tissue samples from members of the family Carcharhinidae from all regions except the western North Atlantic, but we will be very grateful for any properly collected and documented shark tissue sample. If you are willing to help but do not have access to the proper tissue preserving materials, send me your postal address via E-mail and I'll send you tissue collection vials filled with an appropriate preservative. Below are guidelines for collecting and documenting shark tissue samples.
Protocol for Elasmobranch Tissue Collection for Genetic Studies
The basic protocol is very straight forward. There are two very important steps to keep in mind:
- The species identity and other information (sex, length if available, and approximate geographic location of capture) must be recorded correctly. If the identity of the species is uncertain, please note that on the sample tube and on the data sheet accompanying the samples.
- It is absolutely critical that cross-contamination of tissues from one animal to another does not occur. The best way to ensure that cross-contamination does not occur is to use a new cutting tool (e.g. scalpel or razor blade) for each animal. The other option is to rinse and clean off the cutting tool (e.g. knife or scissors) between sampling each animal.
Sampling Steps:
- The best tissue sample is 1 or 2 pieces of fin (dorsal, pectoral, or pelvic) about the size of a thumbnail. A fin clip can be taken without sacrificing the animal. If the animal is to be sacrificed for other studies, then heart and muscle (in that order) are also good tissues for DNA. Fin is best.
- Place sampled tissue in vial provided and record species and sex - plus other data (capture location, length if available) -- in pencil on a piece of paper and slip that in the vial, too. Do not over-pack the vials with tissues: the preservative (either 95% reagent grade ethanol or a solution of EDTA, DMSO, NaCl) should be able to flow around the sample. If the sample is large, please cut it into smaller pieces to fit the vials.
- Please make sure the cap on each vial is closed tightly to prevent leaks during transportation.
- Vials with sample can be kept at room temperature (out of direct sunlight).
Supporting Photography:
If in doubt,
however slightly, of a species identification, place a
numbered or lettered card next to the specimen and photograph them
together. Two views of each specimen are ideal: A)
complete lateral (side) view, and B) underside of head and pectoral
fins. Write the corresponding number or letter onto the specimen data sheet
and insert it into the vial with the tissue sample from that animal. This will facilitate
identification of the source species later.
Submission:
Send tissue samples and photographs to me at:
Richard Martin
ReefQuest Centre for Shark Research
PO Box 48561
595 Burrard Street
Vancouver, BC V7X 1A3
CANADA
