Splake

[hook_line_sinker]

With all of the talk about splake on here in the last few days I thought that this might be a good time to ask this question. I know that I have read several places that splake are sterile. However, a few weeks ago Chincheck and I caught a couple of female splake in Causey which were chuck full of eggs. Does this mean that the males are unable to fertilize or is there another explanation?

Todd
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[Curtisfish]

The Splake raised in Utah hatcheries are supposed to be sterile. It is done using temperature changes during the fishes early life. I don't know all of the details. Just like the "sterile" Rainbows planted in Strawberry, a small percentage of fish are capable of spawning. It is not an exact science, just very close. I've heard estimates of 97-98%.
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[ruger]

Both splake and sterile rainbows will produce eggs and sperm. Their sterility comes from the fact that both are in capable of producing offspring. Also, in the case of splake, they have a hard time figuring out where to spawn since they are a hybrid of a lake trout (lake spawner) and a bookie(stream spawner).

[Fishrmn]

[shocked] Splake are hybrids, and like mules and jennies have all the right parts. The eggs won't fertilize because the chromosomes are never split during meosis back into the normal haploid configuration of either parent. There are a few hybrids where the parent species are very closely related genetically, that can continue to reproduce. Cuttbows come to mind, but I'm not sure if splake are in that same category.
Sterile rainbows are produced by heat shocking the eggs during the 8 to 16 cell stage of development, and a few of them can still reproduce. If they use enough heat, they get 100 percent sterility, but they destroy a lot more eggs than they sterilize. They also sometimes get a tetraploid fish, which has 4 sets of chromosomes, that they spawn with a diploid (two chromosomes) and those offspring are triploids. Triploids (three sets of chromosomes) are not capable of reproducing. They have started testing sterile lake trout, but I haven't heard where they are planning to stock them.
Fishrmn
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[Curtisfish]

I found a question and answer on this very question from the Canadian fisheries. It gives good insight to this question.

[url "http://www.ibiblio.org/london/agriculture/aquaculture/1/msg00295.html"]http://www.ibiblio.org/london/agriculture/aquaculture/1/msg00295.html[/url]

Here is some information from Maine's DWR. I thought that the man made species were unable, but obviously not.



[font "Arial"]Identification: Splake and brook trout have very similar coloration patterns, making it very difficult for the untrained eye to distinguish between the two species. Splake tend to have a slight fork in the tail, a trait passed down from its lake trout parent, while brook trout tend to have no fork or "square" tails.[/font] [ul] [li] [left][font "Arial"]Splake are a hybrid trout resulting from the cross of brook trout and lake trout.[/font][/left] [li] [left][font "Arial"]Splake have been culturally produced since the 1870's.[/font][/left] [li] [left][font "Arial"]This hybrid trout is genetically stable and capable of reproducing. However, splake reproduction has never been documented outside of the hatchery environment.[/font][/left] [li] [left][font "Arial"]Splake are commonly stocked across the northern United States and throughout Canada for the purpose of providing fishing opportunity.[/font][/left][/li][/ul]
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[lonehunter]

i know we have them here in michigan , but i have only seen one in my life . now i know why , thanks guys , i'ts always good to learn something new !
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[Curtisfish]

As fishrmn points out, the problem is in the chromosomes.

The "Temperature shock" sterilization of fish is detailed in the July 2002 issue of "The Ichthyogram". Starting on page 3.

[url "http://www.udwrfes.org/PDF%20Files/Volume%2013-2.pdf"]http://www.udwrfes.org/PDF%20Files/Volume%2013-2.pdf[/url]
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[ruger]

[cool]Is this place cool or what?! As much as I don't like being wrong, I am amazed at the number of times that what I thought was right was actually just rumor. Thanks for the education guys!

[Theekillerbee]

Nice insight Fishrmn.

What method did they used to use (chemically) to sterilize rainbows? It was stopped becuase the FDA withdrew approval of the chemical several years ago. The first bows planted up at strawberry were of this type, and man were they ever big fat footballs! The biggest trout, in so short a period of time, that I've ever seen!
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[Fishrmn]

Theekillerbee,
They put methyltestosterone in the feed. I'm not sure at what size or how long they fed them the additive laced food. I think they had a real high rate of sterility, but the guys that had to feed the fish were suffering headaches and who knows what other ill effects from being around the stuff.
As to the splake being fertile, can anyone tell us whether they spawn with brookies, lakers, or as a seperate group. And what are the offspring called if they breed back with one of the parent species? Also, if they are reproducing, somebody better tell the Utah DWR because they have been calling them sterile, and have planted them with the idea that if they stop planting them that they will be harvested and disappear. Didn't see in the proclamation that the rule was or wasn't designed to protect spawners. I had the impression (coulda been wrong though) that they wanted to protect the bigger splake so they would eat the chubs.
Did I miss that. Can someone head me in the right direction to find that in the proclamation?
Thebirdsandbees,
I thought that the Utah DWR figured the Colorado river would provide current, and the outflow would too, but that the water would be too cold for the stripers. The old fisheries director told me that was one of the biggest mistakes that they had ever made. They figured that maybe a small percentage of the stripers would produce a limited spawn, and that they'd have to plant stripers most of the time.
Fishrmn
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[Curtisfish]

[blush] I can't agree with ruger more on how great this site is. I started in this post believing that all of the Splake produced in this state were sterile by design, then that changed to sterilized from fertile fish, and ending up at some being sterilized and others left able to reproduce. I hate being wrong too, but it is nice to be corrected when it will end up putting more slime on the bottom of the boat. Thanks everyone.
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[aquaman]

hey birdand bees a site i found somewhere on the internet said that wipers can back spawn (i think thats the right term). which means if one of the parent fish is present they are able to spawn with them and reproduce

aquaman
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[Xman]

i read that wipers are capable of reproducing but not likely in the wild. but could and do reproduce in hatcheries. that was new to me since i heard the same story that all hybrids are in capable of reproducing. so what does that mean for the tigers of pineview?
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[Xman]

uh oh the secret is out. that is a interesting story and situation. thanks for sharing it with us. i would imagine that the dwr are aware of the splake running up the creek to try and spawn. what i would be curious about and what you might want to tell this is to find out if they are really spawning or not. i think that would make all the difference in the world. as for the cutts, i think you assessment is right on, it seems whenver cutts have to compete for a food source they usually lose out for some reason. shame your good spot went to $%^& in a handbasket.
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