A fish species that evolved to cope with colder waters...in just three years

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Evolution isn't generally considered a race, but no matter - the tiny stickleback fish is a clear winner. Faced with suddenly colder water, the species managed to adapt in record time - fast enough to potentially beat climate change.

Stickleback fish are very small, no more than ten centimeters long. They originated in the oceans, but after the end of the last Ice Age some 10,000 years ago part of the species split off and colonized freshwater rivers and lakes. The two different groups have since developed very different physical features and behaviors to cope with their surroundings. All of these features made them the perfect candidates to test the speed of their evolutionary processes.

Researchers at the University of British Columbia determined that the freshwater variety of stickleback fish can handle colder temperatures than their oceangoing counterparts, almost certainly because lakes and streams reach far colder temperatures than oceans ever do. To test how fast this adaptation occurred, the researchers, working with colleagues from Sweden and Switzerland, took a bunch of ocean stickleback fish and dropped them in freshwater ponds.

In just three years, the transplanted fish - or, more accurately, their third generation descendants - could handle temperatures 2.5 degrees Celsius colder than they could in the oceans. That's a fairly sizable shift in average temperature, and this speedy adaptation - one that's particularly fast for such a relatively complex organism - sheds an interesting light on how some species might deal with the temperature swings caused by climate change.

UBC researcher Rowan Barrett explains:

That said, he is hardly suggesting we shouldn't worry about the effects of climate change on such species:

Source: http://io9.com/5605038/a-fish-species-that-evolved-to-cope-with-colder-watersin-just-three-years

Rather interesting that the fish could adapt so fast in such a short period of time considering that we always view them as such fragile creatures who cant adapt to a wide variety of conditions.

 

I think that the very adaptability of the stickleback family is one of the very reasons why they are blacklisted here?

I used to keep them back in the UK (where it wasn't illegal to do so) and found they survived just about any water conditions or temperature variation imaginable, short of boiling water or a solid block of ice.

I have to admit to being slightly surprised that they only adapted to a 2.5'C in three years, and not three hours! lol!

Cheers!
G!

 

on 21st June, we were slap bang in the middel of our winter so obviously, I have some potent (4kw geyser elements) in my outside ponds to try maintain a water temp around the 26 deg C margin......
for 3 days, I noticed that the fish were'nt eating as vigorously as usual, so decided that maybe a good water change is necessary.... When I put my hand in the water to submerge the syphoning hose........Ice cold.
The guppy pond was 10deg C and the platy, molly and swordtail ponds were all at 12 degrees...... On checking, the outside plugs tripped on the main switchboard...(probably overload with 4 x 4kw heaters connected to one plug)
The fish were all fine considering that we were having fluctuations between 6 and 22deg C day temperatures. The guppies and Platies seemed the least (if at all) affected by the colder water. The swords and particularly the Mollies were sluggish and slow moving, but all survived.
I wonder if the fact that they are of many generations, (at least 15 years) year round outside stock, has evalutionised them to acclimatise to the elements.... I subsequently left the heaters off and (believe me) measured temps as low as 8 deg C....

 

Although this thread is talking about a blacklisted species, the context is not related to keeping them in SA, or giving out information on how to keep them. Can we please keep it like this. Any mention of wanting, sourcing, owning or generally keeping of this fish will result in:

 

My apologies did not realize they are black listed, kind of hard to memorize the whole list. I thought it was just a good article to share with everyone.

 

No worries Larch. You not describing keeping them. However if this post moves that way we will have to take action.

Regards

 

i have also heard of people conditioning guppies to live in a marine aquarium environment, is this true?


if this is true, would we ever find a strain of guppies that evolves to become a new salt water species all on its own?

 

Why would anyone want guppies in a marine tank? But mollies do very well in saltwater, they get sucked into the pumps very easily but, either very curious or very stupid

 

I don't think that that is an example of evolution. Sticklebacks, much like a handful of other fish found in fluctuating environments, are extremely adaptable. Evolution itself is a process that takes vast amounts of time, from hundreds of thousands to millions of years.

From reading the article, I'm beginning to doubt how well this 'project' was carried out. They failed to mention which species of stickleback they used, and they said that the 'dropped' sticklebacks originating from the ocean into a freshwater environment. I would think acclimitisation would be needed first, but then again maybe I'm just doubting how adaptable this species is. Regardless, I still do not see it fit to call what occured evolution - if they used the same species which also occurs in freshwater environments, then even the oceanic counterparts should still bear at least some of the adaptations to colder water.

Yup - you can do the same with many kinds of livebeaerers, but those from Poecilia (guppies and mollies) are the most well known of the group for being able to do so.

However, as I said earlier, evolution is a process that takes millions of years. For the guppy to effectively 'evolve' into a marine strain, a large number of generations would have to be left in the marine environment to eventually adapt to stay in the environment permanently and most important of all, adapt.

The sole reason why guppies and mollies (and other livebearers) are capable of living in a marine environment is because they are secondary freshwater fish species. What this means is that their ancestors arose from marine environments many millions of years ago and moved into freshwater. A common trait among most secondary freshwater fish is that they have at least some tolerance for saltier water. Another common example of secondary freshwater fish are the cichlids, and several examples from Central America, Africa and Asia show that cichlids still do sometimes venture into saliter waters.