Hi,
Does anyone know of any companies that build trackers (radio or otherwise) that could be implanted into Fundulus notatus. I would like to do some mark- recapture studies and was thinking of using radio transmitters (not sure if they get that small).

Or, if anyone has any other ways to do mark-recapture on Fundulus notatus. I know you can use injections of colored elastomer. Any other ideas?

Thanks!!

There are PIT tags small enough for these fish, but they are rather expensive compared to other methods, which will limit the number of fish you can mark. Injected markers or fin tags are probably the way to go.

There are PIT tags small enough for these fish, but they are rather expensive compared to other methods, which will limit the number of fish you can mark. Injected markers or fin tags are probably the way to go.

Do you know who makes the PIT tags? And what size PIT tags I should be looking for? Thanks.

I totally agree with Nathan. PIT tags should be the way to go. This is where I get my PIT tags for robust redhorse. Here are three sizes. The smallest ones will be fine for studfish.

Radio Telemetry

Species & Habitats

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F. notatus isn't as big as a studfish though. Even the smallest of pit tags are still fairly large. Plus, there isn't much cavity space in a small fish. For the cost and potential mortality what does a PIT tag get you that a VIE won't? You know the exact individual, that is about it. Plus, do you want to pay for a PIT tag to end up in the belly of a smallmouth? VIE's are cheaper, easy to use, and come in many colors (for many cohorts) and don't require a radio reciever or transponder. Plus, because you'd be using topminnows, you could do much of your monitoring from a distance and not actually have to capture the fish, further decreasing the chances of mortality or some covariate entering your expirement. If your VIE colors correspond to a cohort, say males of X-Y mm long, you can still get pretty useful information. One more cost-benefit example...F. notatus aren't exactly as high up the conservation ladder as robust redhorse. There is a good reason why pit tags are used, plus the money is available.

If you REALLY wanted to find out and there is no literature about this (I can't believe there isn't, in fact I would almost put money on there being studies of tagging on F. julisia and a surrogate), you could conduct a small lab study using both tags to check for an acceptable retention and mortality rate at different sizes and sexes.

F. notatus isn't as big as a studfish though. Even the smallest of pit tags are still fairly large. Plus, there isn't much cavity space in a small fish. For the cost and potential mortality what does a PIT tag get you that a VIE won't? You know the exact individual, that is about it. Plus, do you want to pay for a PIT tag to end up in the belly of a smallmouth? VIE's are cheaper, easy to use, and come in many colors (for many cohorts) and don't require a radio reciever or transponder. Plus, because you'd be using topminnows, you could do much of your monitoring from a distance and not actually have to capture the fish, further decreasing the chances of mortality or some covariate entering your expirement. If your VIE colors correspond to a cohort, say males of X-Y mm long, you can still get pretty useful information. One more cost-benefit example...F. notatus aren't exactly as high up the conservation ladder as robust redhorse. There is a good reason why pit tags are used, plus the money is available.

If you REALLY wanted to find out and there is no literature about this (I can't believe there isn't, in fact I would almost put money on there being studies of tagging on F. julisia and a surrogate), you could conduct a small lab study using both tags to check for an acceptable retention and mortality rate at different sizes and sexes.

I agree with Matt - VIE is probably the way to go here.

For the sake of discussion, I will add that we have been successfully tagging brook trout down to 65 mm using 12 mm full-duplex PIT tags. I believe Biomark is now marketing an even smaller tag (8 mm or so). Tags cost $3-6 each, and your looking at a bare minimum of a few hundred dollars for a handheld reader (but you can easily sink $$$ into readers).

Good point. I didn't even think about the relative amount of tissue for the tag to go into is significantly smaller in fish like studfish. I just knew that radio-tags were an absolute no-go. Nathan, Matt and Dave suggestion of visual tags are the most feasible option (monetarily and for fish survival).

Dave, are your trout holding the tags fairly well? In robust redhorse, we have noticed that some of these PIT tags are 'migrating' to other parts of the body where they were not injected. This is sometimes confusing us when certain year-classes are tagged in certain areas, but the tag has shifted to another position.

Good point. I didn't even think about the relative amount of tissue for the tag to go into is significantly smaller in fish like studfish. I just knew that radio-tags were an absolute no-go. Nathan, Matt and Dave suggestion of visual tags are the most feasible option (monetarily and for fish survival).

Dave, are your trout holding the tags fairly well? In robust redhorse, we have noticed that some of these PIT tags are 'migrating' to other parts of the body where they were not injected. This is sometimes confusing us when certain year-classes are tagged in certain areas, but the tag has shifted to another position.

Brook trout tag retention rates seem to vary widely with ontogeny, sex, and surgical technique. We used to tag all fish by making a small incision (~1 mm)
just below the pectoral girdle and pushing the tag in. With this approach, retention rates on small trout seem to be good, but large females are very adept at shedding these tags (we suspect they spawn them out with the eggs). As a result, we're now tagging individuals >130 mm FL via injection in the dorsal sinus - this seems to be much better on large fish.

Thanks everyone! I think elastomer is the way to go! They don't make radio tags small enough for topminnows (smallest I've seen are about 7 mm and 0.25 g) and the PIT tags are likely too big, too. I appreciate everyone's input!