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Dollar x Longear ?


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#21 Guest_centrarchid_*

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Posted 15 December 2008 - 11:42 AM

Moving forward with development.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar at almost 72 h post-fertilization. They were not incubated in same system until the last 24 hours so some differences owing to environment. Differences if obvious, should be apparent by swimmup / exodus.

longear x longear
Attached File  LE_Reelfoot_X_LE_Horshoe__12_15_08___1000_2.5x.jpg   123.16KB   1 downloads


longear x western dollar
Attached File  LE_Reelfoot_X_WD_St.Francis__12_15_08___1000_2.5x.jpg   163.83KB   2 downloads

#22 Guest_centrarchid_*

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Posted 16 December 2008 - 01:50 PM

Starting to see behavioral differences. Longear x longear prolarvae much more active when disturbed than longear x western dollar. Morphologically nothing major stands out as different.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar at 96.5 h post-fertilization.
longear x longear

Attached File  LE_Reelfoot_X_LE_Horshoe_12_16_08___1130_1.6x.jpg   173.9KB   0 downloads



longear x western dollar

Attached File  LE_Reelfoot_X_WD_St._Francis__12_16_08___1130_1.6x.jpg   169.85KB   1 downloads

Edited by centrarchid, 16 December 2008 - 01:52 PM.


#23 Guest_centrarchid_*

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Posted 18 December 2008 - 01:30 PM

We missed images for yesterday because we got too busy. Survival of hybrids still good. All prolarvae getting difficult to capture with plastic pipets. They are also starting to orient with vent down and pectoral fins are evident and moving.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar at 145.25 h post-fertilization.
longear x longear
Attached File  LE_Reelfoot_X_LE_Horshoe_12_18_08___1215_1.6x.jpg   128.18KB   0 downloads


longear x western dollar
Attached File  LE_Reelfoot_X_WD_St._Francis_12_18_08___1215_1.6x.jpg   122.09KB   1 downloads

#24 Guest_centrarchid_*

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Posted 19 December 2008 - 10:32 AM

Fish had to be euthanized with MS-222 for photographs. They now hop along bottom with ventral side down. We still have refinements needed to standardize lighting. Ottoliths in head visible under this lighting regime.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 166.5 h post-fertilization.
longear x longear



longear x western dollar

Attached File  LE_Reelfoot_X_WD_St._Francis_12_19_08___0920_1.6x.jpg   197.05KB   1 downloads

Attached Files


Edited by centrarchid, 19 December 2008 - 10:43 AM.


#25 Guest_fundulus_*

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Posted 19 December 2008 - 11:13 AM

It's a fun series already. Now the yolk sac is much smaller, and jaw development is more pronounced.

#26 Guest_centrarchid_*

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Posted 20 December 2008 - 02:15 PM

Exodus is eminent, likely tonight. Prolarvae now swimming off bottom for brief periods within nest. Fish euthanized with MS-222 for photographs.

We have difference developing but little hard to see. Longear x Western Dollar developing rays of lower caudal lobe faster than longear x longear.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 192 h post-fertilization.
longear x longear

Attached File  LE__X_LE__20.jpg   191.95KB   2 downloads

longear x western dollar

Attached File  LE__X_WD_20.jpg   163.71KB   2 downloads

#27 Guest_centrarchid_*

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Posted 21 December 2008 - 10:10 AM

We have separation!

Longear x longear still operating on engenous reserves (yolk) so still prolarvae. They are also still nest bound. Longear x western dollar sunfish endogenous reserves exhausted and exogenous feeding underway. Brine shrimp nauplii applications began late yesterday. Nauplii remains visible in GIT (gastrointestinal tract) despite major clearing induced by euthanization.

Exodus (swimmup) of longear x western dollar complete. Exodus of longear x longear should occur tonight. Differences in swimmup may be do to variation in early incubation stage when longear x longear held a little cooler.

Pigmentation of longear x western dollar darker and body is apparently less expanded vertically along body axis than longear x longear. Previous experience (with other taxa) suggest pigmentation differences are not a function of exodus.

Longear x western dollar has straiter profile of rostrum / forhead which is evident in most comparisons as prolarvae have developed.

Disparity mentioned previously concerning rays of lower caudal fin lobe maintained ( longear x western dollar more developed) and now more visible owing to adjustments in lighting regimen. Resolution of posted images not as clear as images saved to hard drive (especially in terms of fine detail associated with rays) owing to reduction used to control memory allocation requirments of website.


Fish euthanized with MS-222 for photographs.


Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 213 h post-fertilization.
longear x longear

Attached File  LE__X_LE__21.jpg   126.02KB   1 downloads

longear x western dollar

Attached File  LE__X__WD_21.jpg   122.52KB   2 downloads

Edited by centrarchid, 21 December 2008 - 10:57 AM.


#28 Guest_nativeplanter_*

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Posted 22 December 2008 - 01:13 PM

Centrachid,
These posts are fascinating! Thanks for putting them up!

#29 Guest_BenjaminS_*

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Posted 22 December 2008 - 03:57 PM

I second that! Very awesome pictures, would love to see more as the little ones develop, if that's ok.
Don

#30 Guest_centrarchid_*

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Posted 22 December 2008 - 05:10 PM

Exodus (swimmup) of longear x longear complete. LE x LE hyper and crowd bottom when I approach. I hope not too many hoppers. LE x WD hang in water column and much easier to catch.

Longear x western dollar still has straiter profile of rostrum / forhead. Longear x western dollar alos has more distended swimm baldder which required shoot fish under different restraining conditions (very shallow water).


Fish euthanized with MS-222 for photographs.


Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 241 h post-fertilization.

longear x longear

Attached File  LE__X_LE_22.jpg   149.17KB   0 downloads

longear x western dollar

Attached File  LE__X__WD_22.jpg   132.53KB   1 downloads

#31 Guest_fundulus_*

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Posted 22 December 2008 - 06:26 PM

I notice that these photos were at 241 hrs. post-fertilization. Is this the typical time for swim-ups, in your experience, or do different species vary? Our more limited experience with bluegills and pumpkinseeds from some Massachusetts ponds was that swim-up was usually about 8 days, ~200 hours post-fertilization.

#32 Guest_centrarchid_*

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Posted 22 December 2008 - 07:20 PM

I notice that these photos were at 241 hrs. post-fertilization. Is this the typical time for swim-ups, in your experience, or do different species vary? Our more limited experience with bluegills and pumpkinseeds from some Massachusetts ponds was that swim-up was usually about 8 days, ~200 hours post-fertilization.


We are operating at lower end of temperature range (~ 20 C) for source longear and dollar sunfish populations therefore time to swimmup maybe longer than typical, but I do not say normal. Our northern bluegill of Missouri and pumkinseed derived from central Ohio swimmup at usually on night 6 post fertilization when incubated at about 26 C. Some broods of the former swimmup on night 5 when incubated 29 to 30 C. Broods incubated at about 18 C require between 10 and 11 days. There is more to this but I do not have enough experience to really know what is going on.

#33 Guest_centrarchid_*

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Posted 24 December 2008 - 12:57 PM

Longear x longear swim about in open while hybrids tend to stay in corner and near sides of tank. The longear x longear lighter in color and caudal fin still under going metamorphosis. Vertebrate of longear x longear straighter than in hybrid (this is consistent). Dorsal rays of both are evident, the dorsal spines starting to show. Longear x western dollar still has more distended swimm bladder which rapidly increases in volume when MS-222 added. Requires shooting fish in shallow water.


Fish euthanized with MS-222 for photographs.


Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 288.25 h post-fertilization. Third image of LE x WD hoppers where swimm bladder is not properly inflated.

longear x longear
Attached File  LE__X_LE_24.jpg   128.15KB   0 downloads

longear x western dollar
Attached File  LE__X_WD_24.jpg   136.28KB   0 downloads

longear x western dollar HOPPERS
Attached File  LE_Reelfoot_X_WD_St._Francis_12_24_08___1600_1.6x_HOPPER.jpg   148.25KB   1 downloads

#34 Guest_fundulus_*

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Posted 24 December 2008 - 02:15 PM

Do you typically find more abnormalities such as swimbladder dysfunction in sunfish hybrids? If so, that would obviously have a strong effect on hybrid fitness.

#35 Guest_centrarchid_*

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Posted 24 December 2008 - 02:51 PM

Do you typically find more abnormalities such as swimbladder dysfunction in sunfish hybrids? If so, that would obviously have a strong effect on hybrid fitness.


Generally speaking, we do not see more disfunction in F1 hybrids although F2's and greater tend to be a real mess. Exceptions are with a particular population of coppernose bluegill crossed with any nothern bluegill, regardless of direction and crosses involving warmouth.

The (coppernose x norhtern bluegill) consistently have an upturned caudal-peduncle. Otherwise they grow very well and we will attampt to breed the charactersistic out if the lineages survive future rounds of brood stock selection.

I think warmouth should be in a separate genus. Some crosses involving warmouth are just about inviable and some of those that are viable might just be natural triploids. When we make triploid versions of those same nearly inviable hybrids, viability jumps way up, which is the opposite of most triploids owing to the extreme nature of the triploid induction process.

I think the longear occuring in the North Fork White River in south central Missouri are of hybrid origin involving redbreast sunfish. Some look quite a bit like redbreast and ear tabs are not only all over the place in terms of appearance but tend to be highly assymetrical on a given individual.

The swim bladder problem with longear x western dollar I think has more to due with water quality. We are running them as batches in static 10-gal aquariums and they are not getting priority care. We are doing this more for fun than anything else. Would take replication, broods and tanks, to get handle on whether hybridzation cause or not.

#36 Guest_fundulus_*

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Posted 24 December 2008 - 06:02 PM

OK. I would have guessed that F2's would be much more prone to deformation due to "hybrid breakdown" probably from the increasing failure of regulatory genetic elements. As to warmouths... you may well be right about the accuracy of separate genus status, people seem to have strong opinions about it one way or another.

#37 Guest_centrarchid_*

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Posted 26 December 2008 - 12:33 PM

Both crosses now disperse throughout water column. The LE x LE still lighter in color but disparity decreasing. LE x LE considerably harder to catch , they swim much further when disturbed.

Previous images made with 1.6X objective, this with 1.25X.


To control apparent differences associated with lighting, fish will now be photographed in same image.

Vertebrate of LE x LE still straighter than in hybrid. Median fins (dorsal and anal) are evident, but LE x LE now larger than LE x WD. LE x WD still has more distended swimm bladder, LE x LE is not a hooper despite swimm baldder being so small.

Fish euthanized with MS-222 for photographs.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 336 h post-fertilization.

longear x longear (top) and longear x western dollar (bottom)
Attached File  LE_X_WD_and_LE_X_WD_26.jpg   144.67KB   1 downloads

#38 Guest_centrarchid_*

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Posted 28 December 2008 - 03:17 PM

Objective 1.25X. Both with fork length (FL) = 9.12 mm.

Differences in head shape maintained. The hybrid appear much darker then the LE X LE from a distance than the photograph indicates.

Fish euthanized with MS-222 for photographs.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 387 h post-fertilization.

longear x longear (top) and longear x western dollar (bottom)

Attached File  LE_Reelfoot_X_WD_St._Francis_and_LE_Reelfoot_x_WD_St._Francis_12_28_08___1400_1.25x.jpg   208.07KB   0 downloads

Soon these guys will be large enough to begin feeding with pellets.

Edited by centrarchid, 28 December 2008 - 03:19 PM.


#39 Guest_centrarchid_*

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Posted 30 December 2008 - 11:56 AM

Objective 1.0X. Fork lengths; LE x LE = 10.37 mm, LE x WD = 8.87. LE x WD not a biggin (gonna be a runt). LE x LE pulling ahead. Environmental or genetics? LE x WD not feeding well, need major water change.

Differences in head shape maintained. The LE x LE starting to get pull ahead in terms of ventral - dorsal development. The hybrid appear much darker then the LE X LE from a distance than the photograph indicates.

Fish euthanized with MS-222 for photographs.

Attached images includes half-sibling (same mother) longear x longear for comparison with longear x western dollar ~ 432 h post-fertilization.

longear x longear (top) and longear x western dollar (bottom)

Attached File  LE_Reelfoot_X_WD_St._Francis_and_LE_Reelfoot_x_WD_St._Francis_12_30_08___1400_1.0x.jpg   183.16KB   0 downloads

#40 Guest_gonative_*

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Posted 09 January 2009 - 10:51 PM

Sounds like an American Currents article to me.

Any up to date information?




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