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22 Day Old Scarlet Shiner

Started by Guest_fundulus_* , Dec 20 2006 08:58 PM

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9 replies to this topic

#1 Guest_fundulus_*

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Posted 20 December 2006 - 08:58 PM

I received several bags of larval scarlet shiners, Lythrurus fasciolaris, from Phil Kukulski the other day in an Interstate hand-off. They're now in spawn-specific small aquaria, doing well eating an egg-yolk powder concocted by Phil. Several in one spawn were DOA, so I put them in 10% buffered formaldehyde. Above is a photo of one of them taken with a dissecting 'scope with a built-in digital camera. The magnification is 20X, and the fish is 5.9 mm long from snout tip to caudal tip. The fish was 22 days old. I plan to document larval growth in weekly intervals.

#2 Guest_dsmith73_*

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Posted 22 December 2006 - 08:47 PM

Very nice camera work there. How do these chromatophores distribute in the adult? It would be nice to see a photo-progression.

#3 Guest_fundulus_*

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Posted 23 December 2006 - 10:14 AM

Very nice camera work there. How do these chromatophores distribute in the adult? It would be nice to see a photo-progression.

I also now have photo sets of 20 and 27 day old individuals. As well as the lateral view such as I posted, I have dorsal and ventral shots too. I'll post some in the next coupla days. The chromatophores are present in adults, but aren't as distinct as other pigments appear in the skin. The larvae are almost transparent except for the chromatophores as you can see. The really interesting question is when and how fins appear.

#4 Guest_fundulus_*

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Posted 26 December 2006 - 06:06 PM

As threatened, here are two more photos of juvenile scarlet shiners, Lythrurus fasciolaris. The first one is 20 days old, and is 5.9 mm long.

The second one, below, is 27 days old and 6.25 mm long. I think it looks a little more like a "real" fish.

I have a 31 day old fish ready to photograph, hopefully later this week.

#5 Guest_dsmith73_*

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Posted 27 December 2006 - 10:03 AM

Very nice Bruce. I am very interested in seeing the final progression.

#6 Guest_fundulus_*

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Posted 01 January 2007 - 06:18 PM

Here's a shot of a 32-day-old scarlet shiner. The fish is 6.45 mm long, total length. Still no visible fins besides the caudal. I did a measurement and the mouth is 0.14 mm across; next time you think about the size of fry food, keep that number handy!

#7 Guest_edbihary_*

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Posted 01 January 2007 - 06:39 PM

I did a measurement and the mouth is 0.14 mm across...

I'm curious as to how you measure something so small? I can't picture how you would hold the fish still, and put a measuring tape up to its mouth. Obviously you didn't do that, but how, may I ask, did you do it?

#8 Guest_fundulus_*

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Posted 01 January 2007 - 07:58 PM

I'm curious as to how you measure something so small? I can't picture how you would hold the fish still, and put a measuring tape up to its mouth. Obviously you didn't do that, but how, may I ask, did you do it?

The fish is euthanized first, and then spends 24 hours in a 10% formaldehyde solution with phosphate buffer. The fish are posed on a glass slide with a depression filled with water. As to measuring them, I do it digitally. The software program Motic that comes with the digital camera has a sizing tool, allowing the measurement of lines or area, as long as you know the magnification of the image. So my estimate of 0.14 mm for mouth width was done by drawing a line between the lips of the photo. It's not the exact right perspctive but I think it's reasonably close.

#9 Guest_tricolor_*

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Posted 03 January 2007 - 03:07 PM

Isn't the growth rather slow? 32 days and still no fin?

#10 Guest_fundulus_*

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Posted 03 January 2007 - 03:27 PM

Isn't the growth rather slow? 32 days and still no fin?

Yeah, I think so. There's a lot of size variation among them. Several of the biggest ones now have fins, while some of them are smaller than the individuals I've showed. I've kept them fairly cool, 68 deg. F, which is probably slowing down the growth. I've set the heater higher.