Archive for the ‘brook trout’ Category

Whether a fish likes to hunt down its food or wait for dinner to arrive is linked to the composition of its brain, a University of Guelph researcher has revealed.

Prof. Rob McLaughlin has discovered that foraging behaviour of brook trout is related to the size of a particular region in the fish’s brain.

“We found that the fish that swim around in the open in search of food have larger telencephalons than the fish that sit along the shoreline and wait for food to swim by in the water column,” said the integrative biology professor. “This means there is a correlation between foraging behaviour and brain morphology.”

The telencephalon is a brain region involved with fish movement and use of space.

“It’s responsible for a fish’s ability to swim around to different places and remember landmarks in the environment so they don’t get lost.”

In previous research, McLaughlin discovered that brook trout display two personality types: fish that are active foragers and appear to be risk-takers, and those that are sedentary and apparently more timid.

“These are young fish that have been foraging for less than a month, and we are already seeing a difference in the propensity to take risks and move around. This made us wonder if these differences were significant biologically.”

For the current research, which was recently published in the journal Behavioral Ecology and Sociobiology, McLaughlin and researcher Alexander Wilson collected these two types of fish from the Credit River near Toronto and measured the size of their telencephalon region.

They also measured the brain’s olfactory bulb to ensure that the active foragers did not simply have larger brains overall than the sedentary fish.

“We found there was no significant difference in the size of the olfactory bulb between the two types of fish,” said McLaughlin. “We picked this part of the brain because trout are visual feeders, so the olfactory bulb is not tied to foraging, and it’s also an area that’s near the telencephalon.”

Although this research has shown that the fish’s feeding activity is tied to brain structure, it is still unclear whether behavioural differences reflect initial differences in the brain or whether the brain changes in response to differences in behaviour, he said.

“It’s possible there is something in the environment or in the fish’s genetic makeup that is making some fish more active than others, and this level of activity is altering the brain. There is evidence that fish are plastic and can change structure based on where neurons are developing more rapidly.”

Either way, this finding will help in understanding the neural mechanism behind different foraging behaviours observed in wild animal populations, he said.

“It’s a huge step towards understanding why different types of personalities exist in the same species and how diversity arises in a population. We tend to focus on our impact on the environment and how our actions are reducing biodiversity and overlook processes in the environment that may be creating diversity.”

Contact:
Prof. Robert McLaughlin
Department of Integrative Biology
rlmclaug@uoguelph.ca
519-824-4120, Ext. 53620

For media questions, contact Communications and Public Affairs: Lori Bona Hunt, 519-824-4120, Ext. 53338, or lhunt@uoguelph.ca, or Deirdre Healey, Ext. 56982 or d.healey@exec.uoguelph.ca.

It started out typical of previous Opening Days – with Dave up and “at ‘em” earlier than me.  He started his day be fishing some creeks and rivers and then onto Lake Eugenia, where he caught a few small brook (speckled) trout.

I later met Dave in the afternoon in Orangeville, and we decided to head over to Humber Springs and try our luck for some rainbow trout.  When we arrived, we were told that the fishing had been pretty darn good earlier in the day, but the fish seemed to have stopped taking.  Sure enough, after we set up our fly rods, we found that there was no action whatsoever for quite some time.

But it was still nice to be out on the water, and good to keep up a tradition with Dave where we have hardly missed an Opening Day together since about 1978.  There have been a few in there where emergencies or a major family commitment interfered with our plans, but not many.

I tried a variety of fly patterns with no luck at all, including wets, leech patterns, and after noticing some midge husks on the water, a variety of chironomid buzzer patterns.  But nothing.

Finally, after thinking it was going to be a useless afternoon and evening as far as catching fish, Dave, who had walked over to another part of the pond, called out to me.  When Dave does that, it usually means fish in the neighbourhood.  I scrambled over to where Dave was fishing, to hear him tell me that he had just had a fish on that had broke his fly off.

As well, there were fish rising nearby – appearing to be taking small minows that were swimming near the surface.

A few minutes later after a cast from the bank, Dave hooked and landed a nice rainbow trout of about a pound and a half:

David Moore and his Opening Day Rainbow Trout.

Me? Well, I tied on a fly that was given to me – no idea the name of it. I did get to feel the strike of a fish for the first time in months – in fact three times, I had a fish on but lost it.

As it got dark, the temperature cooled down and the fish seemed to take another break from their feeding.

It wasn’t the most successful Opening Day we’ve had, but after a long winter, just being out fishing is good no matter the number of fish caught or seen.

I’ve had a couple of emails forwarded to me with an image that purports to show a “Tom Turnbull” of Labrador City, Newfoundland holding a very large speckled (brook) trout. The email suggests that Mr. Tom Turnbull recently caught the 17lb trout near “his cabin.”

Turns out that someone is probably playing a trick or pulling a hoax on Tom Turnbull, whoever he might be.

The photo actually shows Tim Matheson of Manitoba with the huge brook trout he caught on Barbe Lake, about 130 km from Sherridon, MB. Tim was not fly fishing though – he was trolling with a crankbait.

Full story (along with the photo that is being emailed, purporting to be Tom Turnbull) is here.