<i>Hynobius nebulosus</i> (Kyoto)

[TJ]

 

[TJ]

T

 

[TJ]

These are "semi-wild" in the sense that over 2,000 of them are living together in a natural environment, but it's part of a research project and they're all PIT-tagged.

PIT (Passive Integrated Transponder) tags are small microchips (about the size of a large grain of rice) that are injected into a salamander so that they can be permanently identified. Researchers use hand-held scanners to detect the PIT tags. The scanner reads the tag's electromagnetic code and displays the tag's number.

 

[TJ]

A tagged and anesthetized H. nebulosus:

 

[pin-pin]

Hi Tim,

Do you have more photos of the process? It is interesting to see how they insert the device without harming the salamander.

 

[TJ]

Heya Pin-pin,

No, sorry to say I don't. At the time I took those pics, I had expected to have another opportunity to observe this procedure, but found out later it had only been scheduled for the one day

I also did not witness the actual insertion of the tag. But I did see newly tagged salamanders still "asleep" or groggy from the anesthetic, watched them revive, and then joined in releasing them into their semi-wild habitat.

The tags are really quite large considering the small size of the animal, and the practice is somewhat controversial (less so with larger caudates like Andrias japonicus). I'm told by those who do it that there's no problem <u>if the procedure is performed correctly</u>. It's particularly difficult and dangerous in the case of females hynobiids in which the egg sacs have become highly developed. As far as I know, the tag's inserted (using a needleless syringe) behind a front shoulder and then repositioned within the body. I'm sure there's a paper about it somewhere.

I also listened to the following interesting lecture...

Use of passive integrated transponder (PIT) tags to individually identify Hynobius kimurae
Misawa, Yasuchika & Matsui, Masafumi

...but didn't take notes. There'll probably be a paper available soon though.

 

[TJ]

"Passive integrated transponders (PIT tags) are becoming more popular in research, and are beginning to be used in amphibians. Sterile implants the size of a grain of rice are injected either subcutaneously or intracoelomically using a specialized syringe. A reader is then passed over the animal to reveal its unique identification number. In addition to being relatively expensive, microchip identification can be inconvenient, since the reader is required whenever an animal needs to be identified. Additionally, many amphibians have the ability to extrude foreign material from their bodies, especially if the material is placed subcutaneously."

Source: ILAR Journal V37(4) 1995http://dels.nas.edu/ilar/jour_online/37_4/37_4Amphibians.asp

 

[joseph]

Tim: Dunno if you know this or not, but how far away can the chips be detected from?

Personally, I would leave most of the populations untagged and only tag a small number for research as Im' sure the tag affects the survivability in some way.

 

[TJ]

Sorry Joseph, I have no idea.

I should have clarified before. This population is only for research. It's in a small habitat surrounded by buildings. All the sals there were either introduced or conceived there. It was started (I don't know when) with only a dozen or a couple dozen adults (I can't recall the precise figures) and some egg sacs. Considering it is now at over 2,000, I'd say the survivability rate is pretty good

Still, I get your point. There may be some whose longevity is affected...

 

[pin-pin]

Ah, too bad the publication will not have any lovely Tim-photos.

FK, (and correct me Tim, if it's wrong) PIT tags are for identification, not positional tracking. This way the researcher can tell "oh, this is salamander #4928" instead of clipping toes. Satellite tags are used for "location" of the animal, but I have yet to see one reduced to the size of a grain of rice (or two, depending on the variety

).

 

[joseph]

True, but I think some distance(such as alerting a researcher to an animal hiding under a rock in front of them)would be useful.

 

[TJ]

Yeah, exactly. In the research habitat mentioned above, there are over 2,000 live salamanders but some 3,000 tags have been used there to date, each costing around $8. So the researchers are understandably keen to recover them even after salamanders there die.