Skip to main content

Adventursome Personalities in Trout

Adventursome Personalities in Trout

https://www.youtube.com/watch?v=K23-ZuA9EX8

According to a recently released study, scientists at Exeter University in England have determined that Guppies have distinct individual personalities. The fish's reactions to various situations and stresses indicated unique coping strategies that can be attributed to individualized cognitive profiles. Parallel university research has correlated the stream movements of Brown Trout to biochemical data in the fish's blood, and appear to have implications for trout anglers wanting to better understand their quarry as well.

Coverage from Timeslive provided the following,

"Scientists from Exeter University in southwest England studied how individual Trinidadian guppy fish behaved in various stressful situations and discovered wide differences in how they responded. The researchers studied their coping strategies in situations designed to trigger various levels of stress. They found their modes of behavior could not simply be explained as risk-taking or risk-averse."


brwntr


"When placed into an unfamiliar environment, we found guppies have various strategies for coping with this stressful situation - many attempt to hide, others try to escape, some explore cautiously," said Tom Houslay, of the university's Centre for Ecology and Conservation.

"The differences between them were consistent over time and in different situations. So, while the behavior of all the guppies changed depending on the situation - for example, all becoming more cautious in more stressful situations - the relative differences between individuals remained intact. The tiny guppies were individually transferred to an unfamiliar tank, to create a mild level of stress, while a higher level of stress was caused by adding models of predatory birds or fish."

While Guppies are not generally considered of interest to fly fishermen, the insight gained from the research may now potentially be extrapolated to trout. A study released within the same news cycle as the Exeter work from the Institute of Biomedical Research at the University of Lleida in Spain has shown that blood chemistry in Brown Trout--analyzed through the new science of metabolomics -- indicates that individual fish can be more inclined to search out new territory or engage in localized migration than others that are inclined to a sedentary lifestyle.

According to the study abstract by lead author Neus Oromi,


"The mechanisms that can contribute in the fish movement strategies and the associated behavior can be complex and related to the physiology, genetic and ecology of each species. In the case of the brown trout (Salmo trutta), in recent research works, individual differences in mobility have been observed in a population living in a high mountain river reach (Pyrenees, NE Spain). The population is mostly sedentary but a small percentage of individuals exhibit a mobile behavior, mainly upstream movements. Metabolomics can reflect changes in the physiological process and can determine different profiles depending on behavior."

The summary of the research concludes that, "The metabolite profiles differentiated the individuals according to the home range classification (sedentary and mobile) and showed different level concentrations of some metabolites, which interact in different pathways. Considering that stream-resident S. trutta in the Flamisell river is mainly sedentary, the small proportion of individuals with mobile behavior, clearly differentiated by the metabolic profiles, can have a relevant function in the population dynamic."

What the heck does this all mean, anyway? In the case of Salmo Trutta, it is interesting as Brown Trout are famously territorial, defending home pools and preferring calmer, predatory lies than other species of trout such as Rainbows. The metabolomics analysis of the Spanish Browns indicates that typically, these sedentary trout will have a home range of not more than 800 meters within a stream, engaging in seasonal forays of only an extra 100 meters to find appropriate spawning beds. During the spawn, salmonids like trout exhibit large increases in hormones that can manifest in physical changes such as development of jaw kypes and more vivid coloration in males.


btff

However, the study made analysis of individual fish that had made broader movements outside of spawning season. The results found that these fish had measurably different levels of metabolic markers such as the stress hormone cortisol, indicating that they may be uniquely more intolerant of pressures being experienced within their home range, such as increased incidence of the presence of fishermen. They just aren't putting up with it.

As every angler knows, large, old fish are smart -- they don't get to be that way by making rash decisions or allowing harassment. If some individual trout that are by nature inclined to seek out more remote or difficult sections of river to elude human predators are genetically predisposed to that behavior, they may spawn local progeny that have the same aversive inclinations. If this is the case, anglers seeking them out may find that strategies such as more stealthy stalking and presentations made from longer distances are to their advantage, even if the fish are less pressured overall.

New available science and associated research is driving increased understanding of fish behavior, which will prove to be invaluable information for future generations of both fisheries managers and anglers alike.

Get Your Fish On.

Plan your next fishing and boating adventure here.

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

See More Recommendations

Popular Videos

Hobie MirageDrive 360 Kayak Propulsion: Amazing Control and Power

Hobie MirageDrive 360 Kayak Propulsion: Amazing Control and Power

The Hobie MirageDrive 360 pedal propulsion system is the pinnacle of kayak control with more efficient fin designs, glide technology and allows the boat to be moved in any direction.

Tying the Double Barrel Popper

Tying the Double Barrel Popper

All these tricks can be put to use on poppers or sliders for anything with fins, from panfish to billfish.

Rio Technical Trout

Rio Technical Trout

Rio Technical Trout

Scientific Anglers Amplitude Infinity

Scientific Anglers Amplitude Infinity

Scientific Anglers Amplitude Infinity

See More Popular Videos

Trending Articles

Hobie's MirageDrive 360 pedal propulsion system offers ultimate kayak control with more efficient fin designs, glide technology and allows the boat to be moved in any direction.Hobie 360 Drive Kayak Propulsion Technology: Power and Control in Any Direction Accessories

Hobie 360 Drive Kayak Propulsion Technology: Power and Control in Any Direction

OSG Editorial Staff - November 01, 2020

Hobie's MirageDrive 360 pedal propulsion system offers ultimate kayak control with more...

Best Panfish Flies Best Panfish Flies Flies

Best Panfish Flies

Skip Morris

Best Panfish Flies

You don't always catch large trout in these alpine lakes and streams, but even the small ones are brightly colored treasures.Alpine Lakes for Remote Monsters Trout

Alpine Lakes for Remote Monsters

Landon Mayer - April 18, 2018

You don't always catch large trout in these alpine lakes and streams, but even the small ones...

The top eight spots for lakes, ponds, and reservoirs.Locating Stillwater Trout Beginners

Locating Stillwater Trout

Ross Purnell

The top eight spots for lakes, ponds, and reservoirs.

See More Trending Articles

More Industry

$20 Million will go to 1,000 grassroots organizations including CalTrout, BTT, and the Wild Salmon Center.
Patagonia Consumers Donate $10 Million, Company Will Match Industry

Patagonia Consumers Donate $10 Million, Company Will Match

Fly Fisherman - January 06, 2020

$20 Million will go to 1,000 grassroots organizations including CalTrout, BTT, and the Wild...

Tom Rosenbauer received the 2019 Izaak Walton Award on March 12, 2019.Tom Rosenbauer Receives Izaak Walton Award Industry

Tom Rosenbauer Receives Izaak Walton Award

Ross Purnell - March 13, 2019

Tom Rosenbauer received the 2019 Izaak Walton Award on March 12, 2019.

Guide Beer first went on sale in March 2019.Guide Beer Grant Industry

Guide Beer Grant

Ross Purnell - January 23, 2020

Guide Beer first went on sale in March 2019.

We need more young people to become fly fishers.The Herb Miller Scholarship for Diversity Industry

The Herb Miller Scholarship for Diversity

Fly Fisherman Staff - January 05, 2021

We need more young people to become fly fishers.

See More Industry

Magazine Cover

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE Arrow

Buy Digital Single Issues

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Fly Fisherman App

Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Phone Icon

Get Digital Access.

All Fly Fisherman subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now