Hi All,

I know I'm *way* overthinking this, but the process is half the fun...

I'm trying (somewhat successfully, I think) to raise gambusia as feeders. I didn't do an overall initial count on my population when I started, but I'm pretty sure I only had 3 males. I recently transferred the population to a new tank, and counted 14 males. Either I was way off in my initial count, or I now have more fish. The thing is, I've never actually seen a female give birth, nor have I seen a fish that I was sure was a new fry. In a tank full of hungry gambusia, only the best hiders would likely make it, so I'm not entirely surprised that I've never seen newborns.

Anyway, this got me wondering about marking fish so that I could track individuals without keeping them in separate tanks. Like I said, this is clearly *way* beyond what one needs to do to just raise feeders, but might be fun.

So... what are the options? If I just want to distinguish "new" fish from "existing fish", a single mark would work. Fin clipping? Looks to me like the "real" way to do it is with Visible Implant Elastomer tags, http://www.nmt.us/products/vie/vie.htm. Multiple colors/mark locations give a way to track individuals, which could be fun. But... it's very expensive stuff for just "playing".

What other options are out there for marking fish?

Thanks,
Jase

I personally use VIE and PIT implants with some of my fish but we are definitely not talking about feeders with that price tag..

I have in the past injected Temporary dye to track specific fish for various reasons (Not much different from what is used in the infamous Dyed / tattooed fish)

Thanks much for the reply. What's available as a temporary dye? Is there one that's less toxic than some of the ones used in the "painted" aquarium fish trade?

Cheers,
Jase

I personally use VIE and PIT implants with some of my fish but we are definitely not talking about feeders with that price tag..

I have in the past injected Temporary dye to track specific fish for various reasons (Not much different from what is used in the infamous Dyed / tattooed fish)

Tattoo ink and regular old food coloring are two I have used..
Food coloring lasts a very short time but is useful at times.

I'm personally not 100% sure what they are using for these painted fish but it would likely be just fine. It is not the dye or ink that causes high mortality in these fish, it is the handling and stress of the procedure that weakens and kills them.

Sharpie.

Hi All,

I know I'm *way* overthinking this, but the process is half the fun...

I'm trying (somewhat successfully, I think) to raise gambusia as feeders. I didn't do an overall initial count on my population when I started, but I'm pretty sure I only had 3 males. I recently transferred the population to a new tank, and counted 14 males. Either I was way off in my initial count, or I now have more fish. The thing is, I've never actually seen a female give birth, nor have I seen a fish that I was sure was a new fry. In a tank full of hungry gambusia, only the best hiders would likely make it, so I'm not entirely surprised that I've never seen newborns.

Anyway, this got me wondering about marking fish so that I could track individuals without keeping them in separate tanks. Like I said, this is clearly *way* beyond what one needs to do to just raise feeders, but might be fun.

So... what are the options? If I just want to distinguish "new" fish from "existing fish", a single mark would work. Fin clipping? Looks to me like the "real" way to do it is with Visible Implant Elastomer tags, http://www.nmt.us/products/vie/vie.htm. Multiple colors/mark locations give a way to track individuals, which could be fun. But... it's very expensive stuff for just "playing".

What other options are out there for marking fish?

Thanks,
Jase

We have been using VIE with sunfishes although retention rates not good when animals constantly scratched while in confinement. The seringe we use for VIE also might a bit harsh for such a little fish. PIT tags will be too big for but all bu the largest females Gambusia. I would use microscissors for pelvic fin clips.

Sharpie.

Are you serious, or just kidding? Always hard to tell with you, Irate. I guess I could potentially see that working rather temporarily if you could manage to dry a fin well enough to mark it.

Are you serious, or just kidding? Always hard to tell with you, Irate. I guess I could potentially see that working rather temporarily if you could manage to dry a fin well enough to mark it.

It's gotta be worth a try!

Ask a vet if you can get some silver nitrate sticks, they will make a non-toxic black mark that usually lasts 6 mo to a year (or two) in elasmobranchs, anywhere from 1-6 months in teleosts, in my experience. With teleosts though, especially something as small as Gambusia spp. you have to be very careful, just a split second contact and then flush with saltwater or saline solution or you will burn through a fin quite quickly!!! (I've disfigured the caudal fins of a few dozen Fundulus and Cyprinodon figuring this out the hard way)

...can't find my copy of Nielson's 'Methods of Marking Fish and Shellfish' at the Moment, but it is a wonderful reference (AFS Press- 1991 or 1992 I believe)
Hope this helps,
-Barrett

Ask a vet if you can get some silver nitrate sticks, they will make a non-toxic black mark that usually lasts 6 mo to a year (or two) in elasmobranchs, anywhere from 1-6 months in teleosts, in my experience.

Excellent, thanks much for the suggestion.