A Tiger's Tale
by: Ben Swigle 4/16/2013
Each January, I have the pleasure of attending the annual statewide meeting of Colorado Parks and Wildlife’s (CPW) fishery biologists. CPW fish biologists are charged with managing Colorado’s publicly accessible waters with the mission of protecting and enhancing fishing opportunities for Colorado’s 900,000 resident and visiting anglers. This meeting sets the stage for fish managers to share successful findings aimed on improving the angling experience, with an eye on implementing triumphs in other regions of the state. Of particular interest this year was the production and stocking of a rarely encountered fish species cheerfully named tiger trout.
Tiger trout are a sterile hybrid of a female brown trout crossed with a male brook trout, with its name derived from the fish’s pronounced vermiculations, resembling the stripes of a tiger. Although it is virtually impossible to catch this fish in a wild setting, tiger trout are spawned at North Delany Lake west of Walden. When fall water temperatures and day length perfectly align, brown trout are cued to begin their annual spawn. Providing the egg component, female brown trout are netted and her eggs are removed by gently stroking the fish’s belly in the direction of a vent, located just in front of the tail. Next, sperm from a male Trapper’s Lake brook trout is added to the pan along with a splash of water, to activate the fertilization process. After stirring the mixture for 90 seconds with a goose feather, the eggs are rinse, stored, and ultimately driven to the Bellvue Hatchery near LaPorte or the Glenwood Springs hatchery. While the hatch rate for a pure brown trout is a remarkable 85%, the hybrid tiger trout hatches at a meager 15-20%. Thus, the poor hatch rate is the limiting factor influencing the greater availability of this species.
Fortunately for anglers salivating to knock this species off the proverbial bucket list, plans are in the works to expand production by collecting trout eggs and sperm at additional lakes. For those that simply cannot wait, a select group waters near Cameron Pass were stocked with tiger trout in 2011, with additional stocking planned for in 2013 for mountain lakes within the Poudre and Big Thompson River drainages. A total of 20 lakes in throughout Colorado have been stocked with this species, now that I’ve given you a few hints I think it’s fair anglers wear out some boot leather chasing this species in Colorado.
Tiger trout are known to be highly piscivorous (fish-eating) and are a good control against stunted populations of small trout and rough fish such as suckers. Amazingly the fish planted near Cameron grew nearly 10 inches in a single season. Armed with new plans strategized at this year’s meeting we’re hoping a larger number of anglers can have the opportunity to catch and photograph their very own tiger trout.
Go Fish Colorado!
Blog content © Ben Swigle
Coyute, CO 4/16/2013 11:47:08 AM
Right on Swigs! I hope we see some more of your guest blogs. :)
Fishful Thinker, CO 4/16/2013 11:56:33 AM
Thanks Swigs...we appreciate any information you want to share with us! CL
moosegoose, CO 4/16/2013 12:56:14 PM
tracks, CO 4/16/2013 1:06:41 PM
Great news and really good to see you here Swigs!
Dangly, CO 4/16/2013 2:07:11 PM
Swigs, great post, very informative, however, I must ask- How much money are we spending on a fish that we can only produce in a lab with a 15-20% success rate? Seems the money could be better spent.
Ben Swigle (Swigs), CO 4/16/2013 2:31:19 PM
Mr. Dangly, tiger trout are only produced AFTER we have met the state's request for pure browns. It generally amounts to 1/2 additional day of netting and tries to meet the growing demand for this species. Working with any animal is a crap shoot sometimes we can fill the state’s request in only 3 days. Other times the female spawners are spread out over a week.
We will likely always come up short on our target number for this species but we've got some new protocols in place (heat and pressure treatment) that may increase the hatch rate. The eggs are shipped to the same facility as the brown trout eggs and we usually send Glenwood a cooler of both browns and tigers. A good point but there is really not much money that would be saved by discontinuing this product.
redleader, CO 4/16/2013 5:34:44 PM
Great story and thanks for the efforts...Now let's get their big brothers theTiger Muskies going to clean out some suckers so we can have a real tiger tale.
reconfisher, WY 4/16/2013 5:36:27 PM
agreed...more tiger musky!
IndieCon, CO 4/16/2013 5:42:21 PM
Mr. Swigle, I sure would love to know which waters "near Cameron Pass" have been stocked. How do I find out? Any chance, if not already, that Lost Lake and Laramie Lake be added? Tigers should thrive in those waters.
Ben Swigle (Swigs), CO 4/16/2013 6:07:04 PM
Indie, see the part about the boot leather. I'm trying to balance the number of folks that would be disappointed if I reveal all the details. Because its in my district I will say tiger trout have been stocked in Yankee Doodle Lake.
I'll likely have a post about tiger muskie in the near future depending on how this goes.
pikeNcolorado, CO 4/16/2013 6:15:54 PM
Awesome info. Looking forward to trying my luck at a few of these. Thanks Ben and can't wait to hear about the Tiger Muskies.
IndieCon, CO 4/16/2013 6:32:27 PM
Ben Swigle, you're the man!
Say, may I suggest that fisheries look into what Manitoba (that's right... a prairie province) is doing with tiger trout?
I've caught and released hundreds of them there 20-25 inches andMB fisheries been particular about the lakes (forage base, summer and winter dissolved oxygen issues, etc.) that they stock tigers in. But they've done so with success. The fish grow like pigs in short order off minnows, leeches, etc.
I can drop a couple names your way of the biologists who've been succeeding with the program there if you'd like. I am suggesting it because I think we've some high plains lakes and several prairie lakes that could grow trophies with the right management.
If not interested, I'm in no way offended. I know you guys have a lot on your platters ALL THE TIME. But they may have some info that could be helpful and you might have some that would help them.
Ben Swigle (Swigs), CO 4/16/2013 6:51:24 PM
Indie, whats your email?
ADub TT, CO 4/16/2013 8:07:13 PM
Swigs... may I call you Swigs ha ha
By far one of thee best blogs I have seen on FX!
Nice to get the 411 from CPW biologist!!
>>Love the adjectives and adverbs!!!!<<
Keep it up, GREAT JOB all y'all do at CPW!
(I emailed a reply to Paul Winkle today stating the same. He replied to my email about Harriman,
Thanks Again!!! A-Dub
Ben Swigle (Swigs), CO 4/16/2013 8:21:35 PM
Yep, my pleasure. Winkle picks up where I leave off South of Boulder. Good walleye fishin in Denver, Winkle is the cause or blame. The only person that does not generally call me Swigs is my wife. No problem, she's my lady.
IndieCon, CO 4/16/2013 11:35:04 PM
BobLoblaw, CO 4/18/2013 4:06:05 AM
A couple of points and a couple of questions. First off let me thank you for all the great work you guys and gals have done with the fisheries in this state, a state that is arid in nature that has remarkable fisheries. Bigger walleyes than Minnesota has says it all! That is my main point, just a great job by you guys!!
Second point like the big wipers I love catching that dont reproduce. Sterile hybrids should be caught and released as many times as possible and not bopped over the head as small juveniles (and I like to eat fish but they make lots of other trout species for consumption). If you catch a Tiger Trout let it go, they were put in there for a reason (fun to catch/admire but mostly to control brook trout or rough fish numbers being the fish eaters they are). Plus being fish eaters these will grow in a hurry and pack on the pounds. Take a picture and put them back!
On to the questions. Since Lake John has an every 5 or 6 year plan it seems with poisoning it and starting over due to minnow and sucker infestations is there any discussions or plans to put Tiger Trout in Lake John? Fish already grow to huge proportions in that lake being entirely a littoral zone type that is photosynthetic food factory. Imagine how big Tiger Trout could grow to in Lake John and they might help control that rough fish population that occurs after what seems to be a set time period until the next rotenone poisoning becomes mandatory.
Lastly while I dont mind expending boot leather to find fishing places (as my in town exploits of discovering saugeye and walleye ponds will attest) I do mind $3.50 a gallon gas and numerous trips running down which lake holds Tigers around Cameron since there are a plethora of lakes I can think of in Zimmerman, Kelly, Trap, Peterson, Long Draw, Joe Wright, Agnes, Ranger Lakes, Ruby Jewell, and North Michigan Creek Res. So is there someone else I could ask since it sounds like you dont want to spill someone elses beans? Again thanks for the job you do and your reply.
Ben Swigle (Swigs), CO 4/18/2013 8:57:01 AM
It comes down to numbers of fish available and past history on particular water.
First the numbers, 1 million fingerling (3-5”) brown trout are stocked statewide, hatchery space is limited and the number is representative of what each biologist requests based on the previous year of sampling. To stock that number of fish it takes 1.2 million eggs or roughly 670 female brown trout that are actually ripe (1,800 eggs per female). By the time we reach 1.2 million eggs the spawning run is generally past its peak and we're subjected to taking eggs from the a smaller number of spawners within North Delany's population. That usually amounts to 300,000 additional eggs x 0.15% survival = 45,000 tiger trout available for the entire state. Rather than putting all the fish in 1 or 2 lakes we divide the product among 15 waters in all regions of the state, thus giving the greatest number of angler’s a water that is within some proximity of their home. The tiger trout are raised to about 4” and we have fairly good survival once they enter the water. This year the final tiger trout number was about 24,000 fish (split among 4 regions), two of my requests (Mary’s Lake and Lake Estes) had to be canceled but 2 requests can be filled for Jenny and Yankee Doodle Lake. Splitting the operation among 2 separate lakes holds promise in that we could hit the peak to 2 different locations. That would also get us home 2 xs as fast as Mr. Dangly noted concerns about the cost of production.
Ben Swigle (Swigs), CO 4/18/2013 9:04:03 AM
Part 2: Past stocking success of a particular water. Lake John was stocked with 24,500 brown trout @ 5 inches in 2001. Return to creel (angler catch) was not great and we noted little decline in the sucker population. Thus, pure brown and most likely tiger trout are not a good fit for Lake John. Next, the sucker infestation was the result of a breach in the shear screen that filters the intake. That screen has been repaired and should keep suckers out of John, which fished quite well this ice season. The fathead minnows in John are readily eaten by the rainbows. Hope that answers your questions. A little research on your end should answer your additional questions.
moosegoose, CO 4/18/2013 12:07:12 PM
Ben, I am glad to hear that the program is going to continue! I really look forward to they next few years and seeing its results.
Dmac3474, CO 4/18/2013 1:18:34 PM
This is awesome i would love for one of those on the other end of my line for the first time!
BobLoblaw, CO 4/20/2013 4:52:39 AM
Thanks for the additional info Ben much appreciated!
Ben Swigle (Swigs), CO 4/21/2013 7:31:38 PM
My pleasure, I worked on some materials this weekend during kids nap time, so I post something else soon. Might review what KoKo posted on walleye spawn as I'll add a finishing touch to walleye spawn 2013.