Fishing with Rod Discussion Forum
Fishing in British Columbia => General Discussion => Topic started by: BladeKid on December 11, 2007, 06:59:02 PM
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I was just wondering what the differences between bull trout and dolly varden are. I tried to find the answer through various websites, and the answer was only vaguely described. Any info would be greatly appreciated. Thank you.
Michael
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When I studied Fisheries at UBC, a friend was doing his Masters thesis on Bull Trout & Dolly Varden. I assisted him during the time with his sample collecting. DNA testing was not yet developed so he collected morphometric data (counts & measurement). There were some differences between Bull Trout & Dollies. Bull trout are landlocked forms of Dolly Varden & are usually found in large inland lakes (eg. Kootenay) while Dollies are found on the coast. The difference in the data he collected may be due to one form being landlocked while the other is often anadromous (sea run). Another example would be the variations found between Interior lake rainbows & steelhead...they are both forms of rainbow trout.
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Wondered that myself one night :
http://www.srd.gov.ab.ca/fishwildlife/status/btrout/cons.html
http://article.pubs.nrc-cnrc.gc.ca/RPAS/RPViewDoc?_handler_=HandleInitialGet&calyLang=eng&journal=cjfas&volume=54&articleFile=f96-289.pdf
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Hi Michaelt,
good question, it was once thought that they were all the same. However, with more research, there's more features which distinguishes the two. There are a few morphological differences (some are very slight) as well as DNA differences differentiating the two different species; dolly varden (Salvelinus malma) and bull trout (Salvelinus confluentus).
A good book to look though is the new one that Dr. JD McPhail just published called "Freshwater fishes of British Columbia". This book is great as it tells you not only unique characteristics, but it's distribution in BC of each species.
As a fisherman, I often look at the size as well as the upper Maxillary as bull trout are often a larger and have longer upper Maxillary than dollies. The upper Maxillary of a bull trout will often go beyond the eye. In the below picture you can sort of see how far back the upper Maxillary passes beyond the eye regardless of the size of the fish. Typically bull trout are more piscivorous than dollies as suggested by the size of mouth and larger teeth, however, dollies are known to also eat fish. (http://img.photobucket.com/albums/v669/mykiss/monster2.jpg)
Also, depending on the watersheds, you'd find more dollies than bulls and vise versa. Yes, dollies are more coastal and bull trout are more interior, however, there are some exceptions as there is a large overlap in distribution e.g. Fraser and a few other watersheds, so you can find them living in the same water systems. For example, the Fraser river, Skagit, Squamish, to name a few has both species.
You can find both species in lakes, as well as rivers and streams. It's true that there are land locked populations, but there are also many that are connected to the sea. I hope that helps.
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PS. I know those listed rivers have bull trout in there because I've done DNA work of char from those systems and there's definitely bull trout in there ;)
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Hi Coryandtrevor!
Your first link is very interesting! I states that the differences between bull trout & dollies were confirmed in 1991 by Haas & McPhail. Well... I was assisting Haas with the collection of the samples before the publication of the paper. Also, it mentioned that hybridization is possible which suggests that bull trout & dollies have not evolved or deviated genetically to such a great extent that they are completely different species and cannot interbreed.
Mykiss, very interesting post! I knew Dr. McPhail, the stickleback specialist, who was interested in variation/speciation due to geographically isolated fish populations. Dr. McPhail was a really nice guy & his lab had tanks of sticklebacks which he was studying. I really enjoyed working with Haas & McPhail, going out in boats and setting traps or nets to collect fish. Hope they are both doing well, I have not seen them for years.
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http://www.fishingwithrod.com/articles/2001/0601_03.html
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
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Como lake ;D ???
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
Not sure exactly but its in Alberta I believe.
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
Is this a trick question? By some definitions ability to mix and produce fertile offspring would mean there is only one species. :P I seem to recall Pitt lake or Pitt river tribs having overlapping spawning going on... kinky.
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
Is this a trick question? By some definitions ability to mix and produce fertile offspring would mean there is only one species. :P I seem to recall Pitt lake or Pitt river tribs having overlapping spawning going on... kinky.
What about Ligers,Tigons and Grizzlars ? Oh My ! :D
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
Is this a trick question? By some definitions ability to mix and produce fertile offspring would mean there is only one species. :P I seem to recall Pitt lake or Pitt river tribs having overlapping spawning going on... kinky.
Ding Ding Ding! The supposed hybrids were collected from Iceworm Creek, which is a trib of the upper Pitt.
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
Is this a trick question? By some definitions ability to mix and produce fertile offspring would mean there is only one species. :P I seem to recall Pitt lake or Pitt river tribs having overlapping spawning going on... kinky.
Ding Ding Ding! The supposed hybrids were collected from Iceworm Creek, which is a trib of the upper Pitt.
Pitt River , Alberta what s the diff ! :'(
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Interesting note on the length of the maxillary as one of the determining factors. When I was a kid growing up and fishing with my dad no one used to call the fish "bulltrout"...we knew them as small mouth or large mouth dollies.
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dollies are bucket mouths and their mouth is almost like a squawfish mouth but bigger and with a hell of alot more teeth while bull char's mouth is thinner and more like a regular trout/char mouth and i find the bulls have bigger shoulders while the dollies are just fat pigs all the way through
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sez here the hybrid is found in Boise creek
http://www.sqwalk.com/bc2007/BMNletterPennerPitt07.pdf
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Trivia Question: Who can name off the top of their head the body of water in which the supposed Dollie/Bull Trout hybrids can be found.
Is this a trick question? By some definitions ability to mix and produce fertile offspring would mean there is only one species. :P I seem to recall Pitt lake or Pitt river tribs having overlapping spawning going on... kinky.
What about Ligers,Tigons and Grizzlars ? Oh My ! :D
It's a Liger. It's Only like My Favorite Animal Ever.
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So if Boise creak is the place of the supposed Hybrid, what is this (caught at the mouth of boise)?
(http://i29.photobucket.com/albums/c269/IH8XC/IMGP2039.jpg)
(http://i29.photobucket.com/albums/c269/IH8XC/IMGP2038.jpg)
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So if Boise creak is the place of the supposed Hybrid, what is this (caught at the mouth of boise)?
(http://i29.photobucket.com/albums/c269/IH8XC/IMGP2039.jpg)
(http://i29.photobucket.com/albums/c269/IH8XC/IMGP2038.jpg)
Not sure what the first pic is, but the second one is a beek. ;D
Hybrids tend to have characteristics that are overlapped by the two parents (ie. number of anal fin rays between anal fin ray numbers of DV and BT, jaw extension neither short or long). Interesting finding of DV/BT hyrbrids is the ability to produce offsprings, which most hybrids cannot do. Mykiss' colleagues are researchers in this field, so he can tell you all more about it (now he has to go find Taylor's papers and read and translate them for us ;D ).
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thank you for all the interesting and helpful info. much appreciated! ;D